# New bow design



## mathewsulmx (Apr 3, 2010)

pm sent.


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## mathewsfan10 (Sep 11, 2010)

very nice how long that take you to draw up in solidworks? and looks good my friend


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## nuts&bolts (Mar 25, 2005)

CNC Machinist said:


> View attachment 1214975
> This is how I spent my thanksgivig....
> 
> Now I neeed to add limbs, cams, string, rest. What do you think of it so far?
> ...













I suggest a Finite Element Analysis.

Looks like you have quite a few holes in the sight window area.

I have concerns about the size of the window just above the stabilizer mounting point, in the riser.

Where is the center of gravity?


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## CNC Machinist (Sep 28, 2003)

nuts&bolts,

Here is a screen shot of center of gravity on the assembly. The version of Solidworks I have, only has SimulationXpress, which I played with on the riser, I'll post a screen shot of that if you want. I'm new to using Solidworks, so all this is "play for now.

Thanks for your comments.


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## CNC Machinist (Sep 28, 2003)

I forgot the screenshot, oops..........:angry:


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## nuts&bolts (Mar 25, 2005)

CNC Machinist said:


> I forgot the screenshot, oops..........:angry:


CG looks good.

Generally speaking,
the tension in the cables will be roughly 300% of the draw weight, when the bow is at rest.

So,
if you can do a force diagram, and look for stress concentrations in the riser...

assuming a tensile load of say 180 lbs for a 60 lb draw weight bow, between the axles...

see where the stress concentrators are located. Then, start applying safety factors.

A 2X safety factor would have your riser trying to resist 360 lbs in tension between the two axles, for a 60 lb draw weight application.
A 3X safety factor would have your riser trying to resist 540 lbs in tension between the two axles.


I think you will find that you have weak points in your structure at the sight window, in one of the aperatures (possibly the 2nd one above the berger holes)
and
the long curved aperature just above the stabilizer mounting bushing. I think the rim under compression will deform and start to buckle.

If you machine the curved aperature and leave a web along the centerline (machine the slot from both sides, but leave a web),
you will simulate half of an I-Beam, essentially a "T" cross-section, and this will increase your stiffness ratio tremendously.


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## zestycj7 (Sep 24, 2010)

Alan, 
If you don't mind me asking, what kind of work do you do?
You are one very knowledgeable person.
Don.


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## CNC Machinist (Sep 28, 2003)

Nuts&Bolts,

I'm using Standard Solidworks 2009. Can you please explain how to run a force diagram. Can I do this on the riser only?? I tried to run SimulationXpress on the assembly, but it said I had to do a motion study 1st??

If I can do the study on just the riser, where should I put the restraint? (handle??), and where should the load go? (flat area and inside holes of where the limb pockets go??)

At the start of Simulation there is the options. (system of units (SI, English IPS) (Load (Force or Pressure, normal to each selected face, or Normal to a reference plane, Force value).

I put a web in the cutout by the stabilizer hole. I really appreciate all the advice you are showing! I'm a newbie when it comes to using Solidworks, and the Standard edition has limits to what I can do with it.


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## nuts&bolts (Mar 25, 2005)

zestycj7 said:


> Alan,
> If you don't mind me asking, what kind of work do you do?
> You are one very knowledgeable person.
> Don.


Hello Don:

My formal training is in civil engineering, with an emphasis on hazardous waste.
Worked at the State Health Department in the Hazardous Waste Division,
so developed expertise in toxicology, air, soil and water treatment. I am an expert
in what makes people sick, chemical-wise, and can figure out how to clean up toxic waste in air, soil and water.

Went into the private sector, and started consulting for large corporations,
in the hazardous waste field.

Semi-retired a short while ago, and then decided to re-entered the work force and started some new work. 
Now working on medical devices.

I was a pre-med student, so have a very solid understanding of biomechanics 
(human anatomy, how the joints work with the muscles).


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## nuts&bolts (Mar 25, 2005)

I would do a static force analysis,
as the first test case.










Assume that the tips of the limbs are holding a 180 lb tensile load,
assuming a 60 lb bow, with the bow at rest....limbs in the un-bent scenario.

Cables are holding the 180 lbs of tension.

In the full draw position,
the 180 lbs of load are split between the bowstring and the cables.

At full draw,
let's say the bowstring is holding say 80% of the load,
and the cables are holding 20% of the load.


You need to model the limbs...limb length, fadeout position (center of bending) and
then, once you know the limb length, and fadeout position,
you can calculate the tangent lines
and calculate the load direction / angles.


Take out two of the slots in the sight window.

Bottom-most slot will fail where you are tangential to the berger holes.
Top-most slot is too tight to the fillet at the top of the sight window, and is a stress concentrator....proximal side of the slot.

After you take out these two slots, redistribute in the available space in the sight window,
but I would leave a safety zone directly above the berger holes and leave a matching safety zone at the top of the sight window....

aesthetics and structural reasons.


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## nuts&bolts (Mar 25, 2005)

CNC Machinist said:


> Nuts&Bolts,
> 
> I'm using Standard Solidworks 2009. Can you please explain how to run a force diagram. Can I do this on the riser only?? I tried to run SimulationXpress on the assembly, but it said I had to do a motion study 1st??
> 
> ...


Bow hand is located at the grip area.


Ideally, the bow hand should represent a distributed load across the grip area,
where the resultant vector would be perpendicular to the long axis of the riser,
located at the center of the grip area.

You need to model the best case,
and both extrema.

So, one extrema,
would be the fella who concentrates his bow arm vector at the pivot point (top of the bow hand).

Point load vector at the deepest part of the curve on the grip.


Other extrema,
is the fella who "heels" the bow hand,
so this would be a resultant vector at the base of the bow hand,
just above the top aperature below the grip.


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## nuts&bolts (Mar 25, 2005)

CNC Machinist said:


> Nuts&Bolts,
> 
> I'm using Standard Solidworks 2009. Can you please explain how to run a force diagram. Can I do this on the riser only?? I tried to run SimulationXpress on the assembly, but it said I had to do a motion study 1st??
> 
> ...



I would run a failure analysis, to find your yield stress point....riser collapses.

Then,
I would figure out what is the max acceptable deflection
and find that design load.


If I am designing a skyscraper, say 100 stories tall....
and I have a crowd of folks on the top floor...100th floor...

the building could be WELL inside the structural limits for strength,
but if the walls and windows are moving during a high wind storm...

and folks can SEE The walls and windows moving.....

this will freak people out, and therefore, is STILL a design failure.

If people cannot SEE the walls and windows moving during a high wind storm,
but they can FEEL the floor moving...can FEEL the floor vibrating slowly....

this is ALSO a design failure.


So,
figure out the load required to make your riser fail (deformation beyond the plastic limit)
AND....

figure out what load is required to make the riser plastically deform (BENDs...some, but returns to the original position)
and how MUCH plastic deformation is TOO MUCH. IF the riser FEELS bendy....this is a design failure.

Gotta set the critierion for HOW MUCH plastic deformation is too much.
Gotta figure out HOW MUCH plastic deformation a customer can FEEL,
and then design for say 50% LESS than that limit....

and that is just for a single static load.

Then,
you need to perform a fatigue study,
and have strain gauges measure the amount of deformation,
when you have a machine draw the bow to full draw,
say for 100,000 cycles
say for 1,000,000 cycles.


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## ullr88 (Oct 19, 2010)

nuts&bolts said:


> Hello Don:
> 
> My formal training is in civil engineering, with an emphasis on hazardous waste.
> Worked at the State Health Department in the Hazardous Waste Division,
> ...


:thumbs_up


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## Nytro69 (Nov 24, 2004)

Here is my question...

How in the world do you if at all possible... Model the strings and cables?


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## nuts&bolts (Mar 25, 2005)

Nytro69 said:


> Here is my question...
> 
> How in the world do you if at all possible... Model the strings and cables?


I would just do a static load diagram.

Need CNC Machinist to tell us what is the limb length,
so we can figure the brace height.

Need to know from CNC Machinist if he is using straight limbs (more of a target bow)
or
if CNC Machinest is planning on using pre-loaded limbs..Bear Archery or PSE Evo style.

Mostly,
I am looking to locate the axles in position...(coordinates)
with the bow at rest...
with the bow at full draw.


Once we have the axle positions (bow at rest....bow at full draw),
then,
we calculate the angles for the bowstring,
and
start assigning horizontal and vertical (x and y components) of the force diagrams.

For now,
we assume that the riser is a rigid body (zero deflection)
and figure out the bending moments,
for the 3 scenarios of the bow hand pressure....

point load at the center of the grip
point load at the pivot point (top of the grip)
point load at the heel of the grip (base of the grip).

Since CNC Machinist is just starting out,
I would like him/her to go through a static force analysis,
to figure out failure modes
and to figure out stress concentrators
and to figure out what design changes are needed to keep deflection to an absolute minimum (shooter wants to FEEL zero torsion and deflection).

Zero deflection (below the limit that the shooter can feel) might be on the order of thousandths at the pivot points on the limb pockets.


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## CNC Machinist (Sep 28, 2003)

Here is a link to my 1st posting on these bows.

http://www.archerytalk.com/vb/showthread.php?t=1537541&highlight=kudlacek

and this one.

http://www.archerytalk.com/vb/showthread.php?t=1482444&highlight=kudlacek

Keep giving your comments, and advice. I would like to say again that I'm doing this for Don Kudlacek, his web site is,


http://genesisarchery.com/

So I'm all ears to what people think. I enjoy other archers input.


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## CNC Machinist (Sep 28, 2003)

Here is REV 3, Comments?


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## nuts&bolts (Mar 25, 2005)

1) what is the new Center of Gravity?

2) I see NEW features..excellent work

3) slot length needs to be shorter

4) curved beams at the limb pockets need to be heavier...these beams are under maximum compressive load, when at full draw (suggest reducing the aperture size at the limb pockets)


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## CNC Machinist (Sep 28, 2003)

If you click on the jpeg picture you can see the triad @ the center of gravity.

















I want to keep the pocket inside geometry at both ends of the riser the same, because I have a fixture made for drilling and tapping the limb bolt holes from the
1st bows we made. I'll have to change the outside area for this.









You have been very helpful with this. Have a great evening.


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## Bean Burrito (Apr 20, 2011)

I would suggest, as N&B said, beefing up the two curved sections. They would work better if completely parallel to the compressive vector i.e. straight bars.


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## nuts&bolts (Mar 25, 2005)

CNC Machinist said:


> If you click on the jpeg picture you can see the triad @ the center of gravity.
> 
> View attachment 1215688
> 
> ...



Nice balance point.

Based on your limb pocket angle,
the brace height will be very comfy.

Finite Element Analysis would be ideal,
but....

assuming billet 6061 aluminum alloy,
you might be within the material strength limits,
for those two arches buttressing the limb pockets.

Keep up the good work,
and say hello to Don.


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## CNC Machinist (Sep 28, 2003)

REV 4, I think???

I have been taking the very helpful advice of nuts&bolts on this and I think it's a winner now.

Thd cutouts in the window area have a little over .500 wall thickness now. The same goes for the areas where the limb pockets mount.

Take a look.....









:thumbs_up:thumbs_up:thumbs_up?


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## nuts&bolts (Mar 25, 2005)

CNC Machinist said:


> REV 4, I think???
> 
> I have been taking the very helpful advice of nuts&bolts on this and I think it's a winner now.
> 
> ...












This design is an improvement.

Now, you can work on improving the radius on all of the edges, for cosmetics.


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## CNC Machinist (Sep 28, 2003)

I've been working on modeling and adding accessories.


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## nuts&bolts (Mar 25, 2005)

CNC Machinist said:


> I've been working on modeling and adding accessories.
> 
> View attachment 1216250


 I thought I recognized the Genesis stabilizer design.

Makes sense, since you are working with Don Kudlacek.


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## theedz (May 31, 2006)

I am not gonna lie, You guys are simply amazing! I think this thread is one of the coolest I have read on here in quite awhile. I like how you have allowed and included the AT community to watch the progression of the design and give us somewhat of an inside look at the beginning stages of a new bow design. I don't think I would be far off in saying that 95% of archers don't know or thought about a lot of the stuff that you have described here. I defintaly am interested in seeing the progression CNC and also reading your knowledge and input N&B. Thanks and keep up the good work!


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## Hoytman_Sax (Oct 8, 2007)

I didn't understand much of the technical talk but nice communication! It was awesome watching the process of setting up a DIY riser/bow... Keep it up!


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## huntin4Christ (Sep 3, 2009)

Keep this thread going.............seeing the progression and logic behind it is fascinating


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## Hoytman_Sax (Oct 8, 2007)

Can't wait to see the finished riser


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## Bean Burrito (Apr 20, 2011)

Just a few suggestions:

Black circle: This is a MASSIVELY stressed area. I've seen very clean breaks right here on Martins and even a Hoyt. The limbs have quite a large moment advantage here so the stresses onn that little bit of metal are big.

Red circles: Screwing the limb bolts right into aluminium is OK but IMO isnt a perfect finish, and I'm not a big fan of it. I think the stainless steel bushings which are drilled perpendicular to their axis and threaded, which ride in holes and have slots through the riser for the limb bolts are neater.

Pink circle: While it's not needed for the sake of the arrow a lip here is a very good idea (otherwise the hand will slide up... to you know, the arrow). It can be substituted with a grip with the flare but IMO that's a half assed way to do it. If you're not working with extrusions and it would cost too much then the lip could be machined from aluminium and bolted on with small allen or TORX head screws.










Here's the limb bolt design I meant:









You could also add some holes underneath where the grip plates would sit to shave off a bit of weight. They don't have to be too big. Holes in this instance are more desirable than slots imo for ease of machining and strength

Also, just another note in general: I'm not sure what you're planning on, but stabilizer bushings in stainless steel are a very nice tough. Constant screwing and unscrewing of stab threads will eventually chew up the aluminium if the utmost care is not taken. Extra stab/v bar/weight mounts on the back of the riser are also a very nice touch. This is of course extra expenditure though so it's up to you and Don to weigh up if it's worth it or not

Edit: Stress


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## carlosii (Feb 25, 2007)

nuts&bolts said:


> CG looks good.
> 
> Generally speaking,
> the tension in the cables will be roughly 300% of the draw weight, when the bow is at rest.
> ...


you took the words right out of my mouth...just what i was going to say.


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## ls3 (Jun 30, 2010)

That's one of the coolest things I've seen on AT. Can't wait to see it


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## Bearlee (Dec 24, 2009)

Bean Burrito said:


> Just a few suggestions:
> 
> Black circle: This is a MASSIVELY stressed area. I've seen very clean breaks right here on Martins and even a Hoyt. The limbs have quite a large moment advantage here so the stresses onn that little bit of metal are big.
> 
> ...


AS a civil engineer, I agree the black circle looks to be the weak link. That would make me nervous. The area to the front of the bow should be in tension, the back side in compression, thus both sides need to be analyzed.
As the OP said about more places for stabilizers, it will concentrate stresses at those areas and will need to be beefed up to support them.

I also think the sight window cut outs are not in the best configuration to be the strongest possible design. A truss type solution would work more efficiently. IT seems the load paths will be on both edges with on the center parts holding them together as lateral bracing. I would choose for the center section to add strength rather than just hold them together. However, if the numbers work ... Go for the desired look.


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## CNC Machinist (Sep 28, 2003)

OK smart people. A little help on this.......

Here are what I know how to do so far. (I Don't really know how to do this the right way, so maybe some of you solidworks users could help me with this).






















I don't know when I will get to making chips on this, there are some changes being made on the 1st bow currently. When I do start the machining, I will take photos of the process, and maybe a video.

I appreciate all the interest this has got. Thanks.


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## nuts&bolts (Mar 25, 2005)

Bearlee said:


> AS a civil engineer, I agree the black circle looks to be the weak link. That would make me nervous. The area to the front of the bow should be in tension, the back side in compression, thus both sides need to be analyzed.
> As the OP said about more places for stabilizers, it will concentrate stresses at those areas and will need to be beefed up to support them.
> 
> I also think the sight window cut outs are not in the best configuration to be the strongest possible design. A truss type solution would work more efficiently. IT seems the load paths will be on both edges with on the center parts holding them together as lateral bracing. I would choose for the center section to add strength rather than just hold them together. However, if the numbers work ... Go for the desired look.


Gentlemen:

6061-T6 aluminum has a yield strength of roughly 35,000 psi.
60 lb bow will have about 180 lbs of load on the axles in the limb tips.

The riser is way over-built. CNC Machinist should consider the total mass of the riser,
and look for opportunities to lighten the riser, where possible.


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## nuts&bolts (Mar 25, 2005)

CNC Machinist said:


> OK smart people. A little help on this.......
> 
> Here are what I know how to do so far. (I Don't really know how to do this the right way, so maybe some of you solidworks users could help me with this).
> 
> ...


CNC Machinist:

Several comments.


a) set your restraint for FACE 1 and FACE 2

b) you need to assume the pre-loaded limb shape, when the bow is at rest.









(SEE yellow lines).

In your picture,
the bow limbs have zero pre-tension,
and this is not the case, when the bow is at rest.










The load vector is only applied at ONE POINT, per limb,
namely at the axle location.

So, set the centerline of the axle location say 3/8ths inches away from the end of the limb
and apply a load at this location, per limb.


IN your animated clip,
you are assuming that the limb is a monolith,
and that you have a CONSTANT cross section for the limb thickness.

This is NOT the case.

What you have is a THICKER section at the limb bolt/limb pocket area
and then....

you get to the FADEOUT, which is a transition zone from thick to thinner
and then,
from the FADEOUT,
you have a new THINNER, cross section.

So,
for modeling purposes,
you have three zones...THICK and then TRANSITION and then THIN. JUST like the crease in your shoe.

Your SHOE HINGES at the crease.

SAME for a compound bow limb.


Another way to put this,
is that the radius of curvature is NOT constant.

ON a race track, this is called a decreasing radius turn or corner.

So,
for your modeling purposes,
assume a simple 2 radius limb.

For the final 1/3 portion of the limb, nearest the axle,
assume the SHORTER radius.

For the first 2/3rds portion of the limb, from the limb bolt/pocket area...
assume the LONGER radius.


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## sawtoothscream (Apr 19, 2008)

keeping an eye on this thread. great stuff


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## nuts&bolts (Mar 25, 2005)

CNC Machinist said:


> OK smart people. A little help on this.......
> 
> Here are what I know how to do so far. (I Don't really know how to do this the right way, so maybe some of you solidworks users could help me with this).
> 
> ...


ONE more thing.

I did a snap shot analysis of your 3D model.

Limbs are too long. Brace height would be way way too long, thereby making your power stroke nearly non-existent.










Assume a hinge point...change in limb stiffness, point of change in radius/curvature. Hook up two arcs...long radius and then shorter radius arcs.

Decide what brace height you want,
and then draw the limbs to scale.

Starting point is the yellow limbs/arcs.

Ending point (full draw) is the orange limbs/arcs.


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## nuts&bolts (Mar 25, 2005)

CNC Machinist said:


> OK smart people. A little help on this.......
> 
> Here are what I know how to do so far. (I Don't really know how to do this the right way, so maybe some of you solidworks users could help me with this).
> 
> ...


Here are the two CENTERS of Rotation, for the limbs.


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## CNC Machinist (Sep 28, 2003)

*Nuts&Bolts,* the "limbs" I just made up for FEA testing, They are not "real limbs", or the size and shape of the limbs for this bow. I had to make them as part of the riser, (all one solid model), because the version of Solidworks I'm using doesn't allow me to do the FEA on assemblies. Isn't this what you said to do?

How can you tell from the jpegs that this bow will have a way way too long brace height, and no power stroke? (Have you been talking to Don K.?).

*Bean Burrito,*Don has SS inserts for the limb bolts, and stabilizer holes that we will be using. I do like the limb bolt design that you showed a picture of. I had already added a stabilizer hole to the back of the riser. So you have the front, side, and back to mount a stabilizer to.

And, can anyone tell me what it means when you get a fortune cookie that reads, *"You would prosper in the field of wacky inventions"??? *Do you think this project is "wacky"? :tongue:


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## nuts&bolts (Mar 25, 2005)

CNC Machinist said:


> *Nuts&Bolts,* the "limbs" I just made up for FEA testing, They are not "real limbs", or the size and shape of the limbs for this bow. I had to make them as part of the riser, (all one solid model), because the version of Solidworks I'm using doesn't allow me to do the FEA on assemblies. Isn't this what you said to do?
> 
> How can you tell from the jpegs that this bow will have a way way too long brace height, and no power stroke? (Have you been talking to Don K.?).
> 
> ...


Relative scale.

Haven't been talking to Don.

Just going on what you have posted here on AT.

You have a very flat limb pocket angle. Almost a parallel limb design...but not quite.


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## nuts&bolts (Mar 25, 2005)

You are making me do this the hard way.

Assuming the grip area is 4-inches long........

you are showing in your animated FEA.....23.1-inch long limbs.

If we assume straight limb blanks (unloaded)...
this will give you a 38.0-inch ATA for the bow.....approximately
and
THE *BRACE HEIGHT will be 11-INCHES*
for the bow in your animated FEA model...assuming 3.0-inch cam diameters.

Soooooo,
if you look at the heavy BLACK lines...

these are 17.4-inch long limbs
which should give you a 34.0-inch ATA bow
and
7.0-inch Brace Height measurement to the axles.

*Assuming 3-inch cams...
the BH would be 8.5 INCHES...even with 17.4-inch straight limb blanks.*


So.....with your limb pocket angle...

if you were looking for a 40-inch ATA target bow with straight limb blanks....
you need a much steeper limb pocket.

Sooooo,
if you were thinking of a 34-inch hunting bow,
you need MUCH SHORTER limb blanks,
in order to get the brace height to something more reasonable.

What brace height are you targeting?


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## nuts&bolts (Mar 25, 2005)

CNC Machinist said:


> *Nuts&Bolts,* the "limbs" I just made up for FEA testing, They are not "real limbs", or the size and shape of the limbs for this bow. I had to make them as part of the riser, (all one solid model), because the version of Solidworks I'm using doesn't allow me to do the FEA on assemblies. Isn't this what you said to do?


Ok.

Just noticed that these are not the "real" limbs.

So,
yes,
the pivot point on the limb pocket takes a lot of compressive stress.

Assuming 6061 T-6 alloy,
how do the loads look on the riser?


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## CNC Machinist (Sep 28, 2003)

The riser is looking really good.

Here is a link to Don's web site. He has pictures, and specs for the 1st risers we built. (11 of them).

http://genesisarchery.com/bows.htm

There are people shooting this bow. So we do have some real time information coming in. I have been trying to come up with a stronger riser, and make it more of a deflex riser. (I moved the throat in front of the centerline a little).

Your advice and knowledge has been very helpful. So by all means keep helping.

You just surprised me when you mentioned the long long brace height, and having no power stroke. Don said the same thing when I moved the throat forward.

As I've said before, I'm new at using Solidworks, and my part in this is that I'm a CNC programmer/Machinist. So you and Don, and anyone else out there that wants to share their knowledge on the subject of bow mechanics I welcome. :thumbs_up


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## nuts&bolts (Mar 25, 2005)

CNC Machinist said:


> The riser is looking really good.
> 
> Here is a link to Don's web site. He has pictures, and specs for the 1st risers we built. (11 of them).
> 
> ...


Haven't spoken with Don,
but good to know we are seeing similar things.

When you moved the throat FORWARDS towards the target, to make a more "deflex" riser....
you obviously increased the brace height...

and since there is NO FREE lunch,
you drastically reduced the power stroke.


So,
Don probably also told you...that a DEFLEX riser (more of a straight riser from limb pocket to limb pocket)
also needs a NEW limb pocket angle (more vertical pocket angle)
to bring the brace height back down to a reasonable amount.


The horizontal measurement, from the throat of the grip to the nock groove touching the center serving...

this TOTAL measurement = brace height + power stroke.


So,
if you MOVE the throat (pivot point of the grip) FORWARDS to get to a straight up and down riser (deflex riser),
then...you bumped UP the BRACE HEIGHT for the same TOTAL MEASUREMENT.

So, therefore,
since we have a GIVE and TAKE......

when the BRACE HEIGHT goes UP...

and you do not change the riser length
and
you do not change the limb pocket angle...

then,
what you GAINED in brace height..
you also LOST the same amount in power stroke.


Sooooo,
I am not sure what your design parameters are...
but,

if you want to use your 23-inch limbs...
then,
you need to decide on the cam radius at full draw
and
you need to decide the ATA for the bow at rest.

If you want to use 23-inch limbs,
then...

you need to radically adjust the limb pocket angles (steeper angles)
so that you can get the brace height down to your design spec.


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## dougtoni1 (Oct 28, 2010)

This is an amazing thread. This would explain why bow designs are always changing so much. Just one change on a bow and everything else has to be modified. Thanks for the insight.


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## iawalleyeguy (Aug 10, 2009)

Wow!This is the coolest thread ever!Thanks Guys!


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## Terrier (Feb 19, 2009)

If you need a cam design aid: http://www.bowhunting.hu/images//cam_tervezesi%20segedlet.pdf

About the limb....
If you would like to define a real limb for the FEA firstly you have to decide the limb design "strategy". Need you a lower deflection value limb (rigider) or a soft characteristic limb? 
If you need an aggressive characteristic bow have to select the rigider limb (80-100 deflection) because the cam design is a simplier for this limb (these cam better look like a simple circle cam)

If you selected the deflection you can define the limb for the FEA. I made an english version calculator about the Barnsdale limbs deflection and moving ratio. http://www.bowhunting.hu/images//barnsdale_deflection.xls
Very important that the real deflection value measure is the two inches moving (measure from the pin of cam). Actually the load and the moving is not linear proportional under the draw cicle but not too big the difference so you can calculate a linear load and moving ratio. Example:
Load of the pin position: 112 pounds
Moving: 2"
So the deflection: 113

If you decided a strategy of the limb design and selected the deflection value you can define the limb load in the FEA. If you aim at the absolutely reality you can make the finite layered limbs model and have to define it like this:








I designed a special Zylon Quartzel composite limb with a new assymetric layer arrangement.









and this is my one of concept bow


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## Terrier (Feb 19, 2009)

This is my another one concept bow......


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## nuts&bolts (Mar 25, 2005)

Terrier said:


> If you need a cam design aid: http://www.bowhunting.hu/images//cam_tervezesi%20segedlet.pdf
> 
> About the limb....
> If you would like to define a real limb for the FEA firstly you have to decide the limb design "strategy". Need you a lower deflection value limb (rigider) or a soft characteristic limb?
> ...


Terrier:

Excellent design work.

My compliments.

Your concept bow is forged billet aluminum, I presume.

Very elegant.

Your control cables attach to pegs on opposite sides of the cams.

Also appears, your concept design uses the string suppressor arms as a cable guide / sliding bar.

Your one piece solid limbs have a LOT of stress, very close to the limb pocket.

Interesting design. Must balance the length of the limb pocket, to the spring constant for your limb blank material.
(I'm assuming you are considering laminated limb blanks).


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## Terrier (Feb 19, 2009)

nuts&bolts said:


> Terrier:
> 
> Excellent design work.
> 
> ...


Thanks.


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## Terrier (Feb 19, 2009)

nuts&bolts said:


> Interesting design. Must balance the length of the limb pocket, to the spring constant for your limb blank material.
> (I'm assuming you are considering laminated limb blanks).


My english knowledge is not the best but I try to summarize the gist of my conclusion.
There are some typical design problem of the limbs.

1, The geometry problem.
There is a stress concentration of the cam fork valey. The original geometry is absolute bad. The problem solverable with a simple geometry changing.
Example:
http://www.bowhunting.hu/images/stories/Balazs/Gordon%20and%20Hunor%20limb.mp4
http://www.bowhunting.hu/images/stories/Balazs/Deformation.mp4


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## Terrier (Feb 19, 2009)

2, The limb pocket and the limb connection point (actually this too is a geometry error)

View attachment 1223124


View attachment 1223125


View attachment 1223126


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## Terrier (Feb 19, 2009)

3, The unidirectional fiber problem

The tensile strenght/elongation of break ration is the best of this fiber (S and E Glass) from the cheaper material but the problem is apparent.
The biaxial and twill woven cloth would solve this problem but the tensile strenght of it is half like the unidirectional cloth. 
There are two possible solution for these problem.
1, Other laminating layer layout
2, Have to use a better tensile strenght biaxial or twill woven cloth (Zylon or Quartzel material)


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## Terrier (Feb 19, 2009)

4, The energy stored problem

The most factory think the best solution of the high energy stored limb is the simple lamination technology. This is just a half justice. 
The absolutly best solution is the asymmetric layer thickness. This is 20% better than a simple laminated version.









This theme is a very far-reaching and there are other aspect too.........


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## Nameless Hunter (Feb 10, 2007)

Cool stuff!
I use SW FEA on my machine designs - luckily my version does assemblies.
I have found out the hard way (to the tune of several $K) that getting accurate results depends heavily on how you set up your test.
Excellent work and good luck!


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## nuts&bolts (Mar 25, 2005)

Terrier said:


> 4, The energy stored problem
> 
> The most factory think the best solution of the high energy stored limb is the simple lamination technology. This is just a half justice.
> The absolutly best solution is the asymmetric layer thickness. This is 20% better than a simple laminated version.
> ...


Yes.

You read my mind.

Asymmetric layer thickness will spread your high concentrated stress at the limb pocket.

The "working area" of the limb (red zone in FEA) needs to be longer
and the cold zone "non-working area" needs to be shorter
so that the majority of the limb is storing energy, as you already know
so you have less DEAD WEIGHT.


Your design is very advanced,
and your design direction is proceeding nicely.

Impressive.


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## nimrod1034 (Oct 31, 2011)

Terrier said:


> This is my another one concept bow......
> 
> View attachment 1223085


That looks awsome. 

Nuts & Bolts have you ever designed any bows?


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## nuts&bolts (Mar 25, 2005)

nimrod1034 said:


> That looks awsome.
> 
> Nuts & Bolts have you ever designed any bows?


Have I ever designed any bows?

Nope.

Design and operate multi-million dollar treatment plants for NASA,
and large private companies? Yes.

Civil design, cleaning up toxic chemicals in soil, groundwater, air...
toxicology (what and how chemicals make people sick), biomechanics
are my specialties...work-wise.


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## nimrod1034 (Oct 31, 2011)

nuts&bolts said:


> Have I ever designed any bows?
> 
> Nope.
> 
> ...


very impressive.
I don't have much understanding of all of this and it is really interesting reading all of this even tho some of it I don't quite understand. 
You are very knowledgeable on this subject and was just wondering if you had any concept designs like Terrier. I really enjoy seeing them.

This thread also gives me a better understanding of why companies do certain things. 

With Mathews honeycomb design on their limbs having so much cut metal cut away are they weaker then many of the other bows out on the market, or do all the reinforcing contact points on it cancel that out? Also instead of having a diamond shape in the middle of the riser would it be possible to have some kind of web design?


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## nuts&bolts (Mar 25, 2005)

nimrod1034 said:


> very impressive.
> I don't have much understanding of all of this and it is really interesting reading all of this even tho some of it I don't quite understand.
> You are very knowledgeable on this subject and was just wondering if you had any concept designs like Terrier. I really enjoy seeing them.
> 
> ...


hello nimrod1034:

One of the strongest shapes for a frame is the triangle.

So, a honeycomb design can be very solid.

The large bow manufacturers are using computer control milling machines (router on steriods).
They start with a solid block of high strength aluminum, and then start making swiss cheese...drill out precision holes (cavities).

As you know,
if you have worked hardwood with a router bit, spinning at 20,000 rpm,
the wood can burn if you go too slow (wood gets hot)
and
the cut can get rough if you go too fast (poor finish...milling marks).

So,
you get out the sandpaper and start sanding.

Well,
for a riser, you will make a rough cut
and then start taking finer and finer cuts to sneak up on the final dimension for the cavity (hole).

If you take a round-over bit (small diameter) and smooth out ALL edges of holes,
this LOOKs good and helps to prevent hot spots (points / locations where bending pressure can concentrate.....e.g. at full draw).

When you have the raw riser completely milled out (finish size)
then,
you start the heat treating magic.

Depending on the material,
there are different recipes for ramping UP THE HEAT,
then slowly cooling the metal...

to relieve internal stresses, that were introduced into the riser, during machine work.

Kinda like a sitting in a sauna / steam bath, to get all the nervous energy out of the riser.

Then,
when the riser is all evened out...internally...no more hot spots for stress...
then,
gotta do some more temperature magic,
to bring the strength and hardness up to spec.

Expensive steps to get metal to do what we want...rigid, ZERO twisting (as little as possible), lightweight,
AND....

not feel like a tuning fork, everytime we launch an arrow up to top speed (300 fps +),
time and time and time again.



Fellas like CNC Machinst and Terrier do the hard work, coming up with the design...ingredient list and sizes/dimensions and materials.

Then,
gotta build it correctly.

Terrier shows up pictures of what happens,
when we choose the wrong ingredients....(de-lamination)....

so,
manufacturers have to BOTH select the latest design for limb blanks (5 layer laminated limbs)
and
play around with limb pocket angles,
play around with limb pocket depth (front to back length of the limb pocket)
and 
balance that with the shape of the thickness of the limb (some sections thick...some sections thin...some sections parallel...some sections tapered...maybe).


Next step....

CAM DESIGN.


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## Terrier (Feb 19, 2009)

nuts&bolts said:


> Yes.
> 
> You read my mind.
> 
> ...


Thank you. 
There are two aspects in terms of asymmetric layer thickness. 

1, The stress of connection point of the two difference layer has to be same in the both material under the tension. If it is not same the epoxy has to cope with the stress difference between the two layer and the bonding will be weak.
If we can change the thickness of layer in each cross-section position we can bear on this according the location appear stress.








2, Your conclusion is absolute correct. The our aim is the limb work in the biggest volume, but there is a rational limit of it..... The most limb work in the pocket position too. What we sacrifice with this?

This is my designed limb pocket side with the significant geometry transition









The lower frequency vibration lose on the whole in the pocket position so the bow vibration is lower. This solution solve the typical Mathews limb problem too....









The only one disadvantage of this solution the pocket section of limb is passive so not work but the virtue is better significant.

There is another very interest theme too. It is the epoxy systems........


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## nuts&bolts (Mar 25, 2005)

Terrier said:


> Thank you.
> There are two aspects in terms of asymmetric layer thickness.
> 
> 1, The stress of connection point of the two difference layer has to be same in the both material under the tension. If it is not same the epoxy has to cope with the stress difference between the two layer and the bonding will be weak.
> ...


Terrier:

I see one primary trouble.

With such long split limbs,
I see that you will have difficulty
to prevent axle torsion...

if we are talking the top axle,
with such long, narrow split limbs (but joined at the pocket),

you have nearly zero resistance
for the axle to drop on one corner (left corner wants to drop lower on a RH bow with cable guard)

and the top cam to rotate anti - clockwise,
if we are talking a RH bow with a cable guard.

Maybe you are considering a shoot through system?

Maybe you are considering the cam system with two control cables
and pegs on the outside of the cam,
but on opposite sides (left side peg for top cam and right side peg for bottom cam)?

I like the FEA stress signature,
for your long split limbs, but connected at the pocket.


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## Terrier (Feb 19, 2009)

nuts&bolts said:


> Terrier:
> 
> I see one primary trouble.
> 
> ...


Yes, the cam lean is a big problem and have to find a solution for this definitely.
This is a possible solution for this problem. Maybe unbeliveable but the G5 ceramic cable slide is not outwear the cables and it is a very simple solution without moving parts.








The only one problem is the bigger riser torsion so I design to produce it from the carbon laminating. 

About the pocket and limb connection. My pictures are just a parts from my bow design. I made some analysis about the complete assemble and defined the each bolt and other (pocket/limb) connection point.
Unfortunately lost the analysis database about it and the new calculation approx. two day with my four processor opteron workstation


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## Terrier (Feb 19, 2009)

Here is another picture


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## SilentElk (Oct 6, 2004)

Terrier said:


> Yes, the cam lean is a big problem and have to find a solution for this definitely.
> This is a possible solution for this problem. Maybe unbeliveable but the G5 ceramic cable slide is not outwear the cables and it is a very simple solution without moving parts.
> View attachment 1223913
> 
> ...


I have often envisioned a similiar setup to this Terrier. This thread has been a good read.

On another note that was mentioned earlier in this thread by NutsBolts; Heat treating. I had not considered heat treating to be a factor in a machined part. I find further information regarding this critcal in the sense I hope to be cutting chips on a riser in about a month. Will heat treating of 6061 be required? I understand if something welded and subjected to higher temps, this would be critical.

My back ground is basic. I have machined some very basic items using manual bridgeport mill out of 6061 but nothing as critical as a riser. The riser I will just have made at a local machine shop as I dont have CNC available. I program on Solidworks and fairly familiar with it as I have used it for 6 years but the last 3 or 4 years has been more of hobby than for actual work.


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## nuts&bolts (Mar 25, 2005)

SilentElk said:


> I have often envisioned a similiar setup to this Terrier. This thread has been a good read.
> 
> On another note that was mentioned earlier in this thread by NutsBolts; Heat treating. I had not considered heat treating to be a factor in a machined part. I find further information regarding this critcal in the sense I hope to be cutting chips on a riser in about a month. Will heat treating of 6061 be required? I understand if something welded and subjected to higher temps, this would be critical.
> 
> My back ground is basic. I have machined some very basic items using manual bridgeport mill out of 6061 but nothing as critical as a riser. The riser I will just have made at a local machine shop as I dont have CNC available. I program on Solidworks and fairly familiar with it as I have used it for 6 years but the last 3 or 4 years has been more of hobby than for actual work.


Primarily,
my concern is stress relief in the riser.

Here is a little "something" about heat treatment for aluminum.

http://www.eurospares.com/graphics/metalwork/MIL-H-6088G.pdf


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## SilentElk (Oct 6, 2004)

Where would I find someone to do a heat treatment?


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## nuts&bolts (Mar 25, 2005)

SilentElk said:


> Where would I find someone to do a heat treatment?


Hello SilentElk:

http://www.jmpforming.com/aluminum-heat-treating.htm

You can contact them for a quote,
but the cost will be probably be through the roof for a one-off prototype.


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## Terrier (Feb 19, 2009)

SilentElk said:


> I have often envisioned a similiar setup to this Terrier. This thread has been a good read.
> 
> On another note that was mentioned earlier in this thread by NutsBolts; Heat treating. I had not considered heat treating to be a factor in a machined part. I find further information regarding this critcal in the sense I hope to be cutting chips on a riser in about a month. Will heat treating of 6061 be required? I understand if something welded and subjected to higher temps, this would be critical.
> 
> My back ground is basic. I have machined some very basic items using manual bridgeport mill out of 6061 but nothing as critical as a riser. The riser I will just have made at a local machine shop as I dont have CNC available. I program on Solidworks and fairly familiar with it as I have used it for 6 years but the last 3 or 4 years has been more of hobby than for actual work.


The 6065 and 7075-T6 aluminium can heat treating by the "artificial ageing" method. Actually we can buy these materials in heat treated status here in Europe. 
If you have a manual milling machine make a profile sheet by first like this:








and cut the contour with water jet. Very important the older types water jet cut aslant so you need newest machine.


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## Nameless Hunter (Feb 10, 2007)

Terrier said:


> The 6065 and 7075-T6 aluminium can heat treating by the "artificial ageing" method. Actually we can buy these materials in heat treated status here in Europe.
> If you have a manual milling machine make a profile sheet by first like this:
> View attachment 1224624
> 
> ...


It's more of an offset vs an angle when cutting with a waterjet without a dynamic head.
Whether 1/4" thick or 2" thick, the bottom of the part could be anywhere from "0" to 0.008" larger than the top surface - depending on cut speed and setup.
I'm looking at a 2 1/2" alum piece now that is 0.005" larger on the bottom edge.
You can get perpendicular edges if you cut slow enough but having a dynamic head makes it a lot easier.


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## Terrier (Feb 19, 2009)

MOTU said:


> It's more of an offset vs an angle when cutting with a waterjet without a dynamic head.
> Whether 1/4" thick or 2" thick, the bottom of the part could be anywhere from "0" to 0.008" larger than the top surface - depending on cut speed and setup.
> I'm looking at a 2 1/2" alum piece now that is 0.005" larger on the bottom edge.
> You can get perpendicular edges if you cut slow enough but having a dynamic head makes it a lot easier.


Yes, thanks. You summarized the important things.... I can't to express myself easy.


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## orarcher (Jun 3, 2006)

My brain hurts just trying to understand this stuff !!! Looking forward to seeing some finished bows !! Cool thread thanks !!!


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## UniGram (Dec 11, 2010)

Actually, for first prototypes watercut material can be quite sufficient. The surface is not perfect, but mock ups rarely are.
These are fine for checking the angle of the pockets and even DFC for the cam. But getting the cam just right I find very challenging. I am now on my 3rd prototype and I have chosen a similar path to OK in Germany, They design is great for a first time builder.


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## Nameless Hunter (Feb 10, 2007)

Terrier said:


> Yes, thanks. You summarized the important things.... I can't to express myself easy.


I would say your command of the English language looks pretty good to me - better than some of my American customers. :darkbeer:


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## Terrier (Feb 19, 2009)

MOTU said:


> I would say your command of the English language looks pretty good to me - better than some of my American customers. :darkbeer:


Thanks :darkbeer:


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## Highball (Jul 17, 2007)

Just when I was starting to feel smart, I come across a thread like this...awesome!


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## PAracer56 (Dec 7, 2011)

That is the down fall of heat treating. think of it as a heating bill for a house (if you have to that is) now a one off part will have to be heated up at a certain temp over a period of time so when doing one part over say a manufacture doing 1000 parts cost is high. they have to throw one part in over being able to run multipule at once and cant throw your part in with another run due to the fact a slight amount of heat can effect it greatly. great work wish i had a seat of solidworks to play with. another thing is with solid works I have had issues with cams in the past when trying to put it in motion (if you are going to do so in a modle) im thinking the issue was that the actual lobe of the cam had to be extruded first as a hole and then bosses on both side added in after. 

good job :thumbs_up


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## PAracer56 (Dec 7, 2011)

could not find an edit post icon so forgive me if there is one. my question is you mentioned that you are limiting your design due to already having a jig made for machining. i know they are expensive to build; however, i feel it would be worth while to build a new one if you can make a major advance with your design. even at that you may even figure out a design that would make it much easier to use.


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## NoFences4Me (Jan 22, 2009)

Great thread!


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## CNC Machinist (Sep 28, 2003)

I'm really amazed that this thread has gotten so many views, replies. I've learned a great deal from all of this.

PAracer56: I'm not letting the jig be a limiting factor. There are many factors that play a roll with this bow. If you have followed this thread since the beginning, The bow is for Don Kudlacek, http://genesisarchery.com/, Don and his wife are retired, living on Social Security. Don purchased a smaller Haas mill a few years back. So he doesn't have the cash flow that others have. So when that factors in you can only imagine how that limits you, (tooling, fixtures, material, size and kind of machine) The riser almost doesn't fit when we position it to drill and tap the holes for the limb pockets. (it has to hang off the edge of the table, and the machines travel can just reach.

I found a couple of utube videos today that might demonstrate what I mean.

http://www.youtube.com/watch?v=6up_wy-ClQs

http://www.youtube.com/watch?v=ut2xiJFFJBA&feature=related

http://www.youtube.com/watch?v=YGOsGMz0aH4&feature=related

You can see in these videos that they are much bigger machines, a vertical mill, and horizontal mill, and one with a rotary axis. I do not have these options.

Have a great weekend every one.


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## nuts&bolts (Mar 25, 2005)

CNC Machinist said:


> I'm really amazed that this thread has gotten so many views, replies. I've learned a great deal from all of this.
> 
> PAracer56: I'm not letting the jig be a limiting factor. There are many factors that play a roll with this bow. If you have followed this thread since the beginning, The bow is for Don Kudlacek, http://genesisarchery.com/, Don and his wife are retired, living on Social Security. Don purchased a smaller Haas mill a few years back. So he doesn't have the cash flow that others have. So when that factors in you can only imagine how that limits you, (tooling, fixtures, material, size and kind of machine) The riser almost doesn't fit when we position it to drill and tap the holes for the limb pockets. (it has to hang off the edge of the table, and the machines travel can just reach.
> 
> ...


Keep up the good work!

Each new design gets better and better.


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## Terrier (Feb 19, 2009)

CNC Machinist

What is the limb made from?


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## PAracer56 (Dec 7, 2011)

CNC Machinist said:


> I'm really amazed that this thread has gotten so many views, replies. I've learned a great deal from all of this.
> 
> PAracer56: I'm not letting the jig be a limiting factor. There are many factors that play a roll with this bow. If you have followed this thread since the beginning, The bow is for Don Kudlacek, http://genesisarchery.com/, Don and his wife are retired, living on Social Security. Don purchased a smaller Haas mill a few years back. So he doesn't have the cash flow that others have. So when that factors in you can only imagine how that limits you, (tooling, fixtures, material, size and kind of machine) The riser almost doesn't fit when we position it to drill and tap the holes for the limb pockets. (it has to hang off the edge of the table, and the machines travel can just reach.
> 
> ...


Im a new guy on here so i just breifly read threw some of the posts. There is a lot of good info in here. on a side note what model hass machine is being used. the links are not working for me at the moment (video currently unavailable). at the price of these cnc machines its understandable that it is hard for someone on ss to get a machine with enough travel let alone to be able to aford tool holders and tooling.


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## CNC Machinist (Sep 28, 2003)

PAracer56,
The mill is a Haas VF-OE. It has no rotary, and a very small memory in the control. I've tried to DNC the machine in the past with not much luck. (program runs for awhile, and then sends an alarm)!!! So, we have tried to simplify the design to make it more cost effective to machine, and more affordable to build.

If I could build a bow without limitations, it would be the fanciest bow you would ever dream of.

The follow attachment is a picture of a riser Don had built years ago. I would like to build one similar one of these days. (A shoot-thru riser).









I had started a cad model a long time ago, but got to busy to work on it again.









I have seen since starting this thread that there are others who are working on their own designs, so good luck, and keep on it.


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## Nytro69 (Nov 24, 2004)

I feel your pain on the limitations of the machine controller... All we have are older Hurco Utilimax controlled machines one small knee mill and two enclosed mills with tool changers and cat 50 tooling... Luckily I've been able to trickle feed the code to the controller via hyper-terminal for the more complicated programs etc... But that in itself presents it's own set of challenges. That being said. There really is not limit to what you can machine even with a basic vertical mill... Your only real limit is your creativity and fixture building imagination. Although you really can only work inside the envelope you are given but I've done large parts on the Hurco before... I had to machine a set of transfer rails that were about 12 feet long... I just took a plasma cutter to the mill's enclosure fed the rails through the holes in the side and leap-frogged my part zero along the rail as I went... Sometimes you just have to do what you can with what you have. But it helps to have a good imagination. One thing I've found Over the years in this business is... "If you need a tool to do a job and don't buy it today... You will have paid for that tool many times over by tomorrow..." Every time without fail when I've tried to work around not having the right tool for the job I've inevitably paid for that decision dearly in the end... But you do what you have to when doing low volume or prototype work...

Have you guys given any thought to finalizing a design that you like and then just contract the machine work out to a job shop with the capabilities to do the part just the way you design? If the volume is there you can usually get good per part pricing... Just a suggestion.

Good luck

Let me know if I can be of any assistance


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## CNC Machinist (Sep 28, 2003)

Nytro69,

Thanks for your reply. I'm doing this work for Don (Pro bono), and I only have spare time on the week-ends to drive to his house (35 miles) to work on this. So that also adds to when we will be building more risers.

I've been a machinist for over 30 years now, a CNC programmer/machinist going on 16 years now. In that time I've also had to use my imagination on jobs. Don can not afford to have someone else make these bows. Since he is retired, his time and labor is free. I'm sorry to say that it's my part in this project that keeps it from going forward at this time. (A full time job that is).

How busy is the shop you work for? :thumbs_up:thumbs_up:thumbs_up


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## PAracer56 (Dec 7, 2011)

it may just be me or my luck with hass machines but they seem a tad bit more finicky of a machine over say a mori seiki. again im a new guy to the cnc world compared to most of the guys on here. are these programs written using mastercam or an equivalent program or hand written? i doubt with your experience that i could help much but again this thread is a great read.


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## CarbonExpress (Sep 5, 2011)

This is awesome. Nuts and bolts and CNC go pick up some engineering jobs at a bow company lol


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## GoosebyFLuFLu (Aug 12, 2011)

It kind of looks like a Oneida bow.


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## CNC Machinist (Sep 28, 2003)

GoosebyFluFlu,

Are you talking about this bow?


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## CNC Machinist (Sep 28, 2003)

I've been modeling my surelock sight and adding it to my bow model. I still need to model the rest, limbs, cams, string.

















What do you think?


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## Oneida Bows (Nov 24, 2008)

Looks Great :thumbs_up


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## Shootin Jim (Dec 27, 2010)

Haas controls have always been a pain in the exit. The newest ones I've run were 2009, and they still suck.


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## CNC Machinist (Sep 28, 2003)

I personally like the Hass controls. I've ran Fanuc controlled Mills (Mori-Seiki's, Akiri-Seiki's, Femco, Haas and a Saeilo horizontal), out of those CNC mills, I like the Haas control best.

The quick set-up of tooling, offset numbers being the same for diameter, and length, (Tool 1 is H1, D1). Just last week I scraped a part by not seeing my diameter offset number was the same as the tool number. (This is a no-no on Mori-Seiki's) endmill headed north, right through the side wall of my part! *och!*:angry:

Have a Merry Christmas.


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## nuts&bolts (Mar 25, 2005)

CNC Machinist said:


> I've been modeling my surelock sight and adding it to my bow model. I still need to model the rest, limbs, cams, string.
> 
> View attachment 1230962
> 
> ...


Limb pocket angle is MUCH MUCH better, than before.


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## turkeyhunter60 (Apr 19, 2010)

I'm in for the Thread.....Interesting read.....Keep it going, I'm learning some good stuff on here...CNC.....Don't know Don Kulachek personally....But Don and I have a Mutual Friend down Here...Chuck Lynde....AKA.... Windy Lindy......:thumbs_up:darkbeer:


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## Terrier (Feb 19, 2009)

If you don't define the limb specification you can't define the exact limb pocket angle. 
You have to know:
- the desirable brace height
- the desirable ATA distance
- the limb lenght
- the limb moving

Here is a typical sample about a Barnsdale limb.









1 pos. - without tension
2 pos - before the draw
3 pos - under the draw


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## Terrier (Feb 19, 2009)

Here is a possible limb strategy

Material:
S2 Glass
Geometry:
short (10-12) limb because the palpable vibration is lower of it (higher frequency)
Position:
Paralell position because the frequency amplitude direction is near vertical


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## GenesisAlpha (Jun 26, 2009)

This is a great thread, CNC awesome work and Thank You for your help working with Don. Good things will come from your hard work!

Bob


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## CNC Machinist (Sep 28, 2003)

Well, I just got my bow today. It's one of the 1st 10 risers we machined. Don needed to make longer limbs for my 31" draw length.

I must say that after getting it all set-up at Don's house I came home and did some testing. (I shoot it through the chronograph).

Here are my findings for those people who want to know what this bow shoots.....

The bow is 40" axle to axle, 8 1/2" brace height, 52.3 pounds draw weight, holding 20.5 pounds, (measured with the easton hand held digital scale), the arrows where 320 grain Arrow Dynamics, 3 vanes, 29" long. (252 feet per second).

My Martin Septer III set at the same poundage with Nitrous X cams, and the same arrow, was (253 feet per second).

So now we know.

Here's a couple of pictures to look at.


























The last picture shows some of my other bows, (Can a guy really have to many bows???)

One last thing...I'm happy to be able now to shoot one of the bows I have made so far.


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## nuts&bolts (Mar 25, 2005)

CNC Machinist said:


> Well, I just got my bow today. It's one of the 1st 10 risers we machined. Don needed to make longer limbs for my 31" draw length.
> 
> I must say that after getting it all set-up at Don's house I came home and did some testing. (I shoot it through the chronograph).
> 
> ...


Very nice, CNC Machinist.

Slight reflex in the riser.

Tapered limbs...interesting.

Cannot see a limb bolt. Hmmmm.

Looks like you are using the ENTIRE limb pocket as the pivot point,
for draw weight adjustment. Very nice.


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## CNC Machinist (Sep 28, 2003)

Terrier,

Don said he makes the limbs from Gordon Composites Power tuff glass.


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## Oneida Bows (Nov 24, 2008)

Looks Great CNC machinest and as stated great thread :thumbs_up


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## Unk Bond (Aug 1, 2004)

Great thread CNC machinist.
=====================
Hello All


Nuts & Bolts I always enjoy your line sketches. And good points of advise.

==========

Now I own the pryor version, of this riser. And my limb pockets, might not be on the same degree, as this new riser has. To attain more speed. But I feel my Quad Fire bow for a indoor bow, it has out performed any bow I have at rest now. Being my Hoyt bows and others. 
Now I give my Quad Fire bow a rating of 99.999999999.9 % and with a :thumbs_up for smoothness.

Now my bow may rate a 100% with your style of holding a bow. But as I will point out in a picture of the area, that seems to give me top knuckle web pressure with a corner, in that area of my thumb knuckle. While holding the bow at full draw.by having that corner design, at the top right side of the the bow shelf.

In this new model riser, there looks to be more of a rounded curve in that area. Which I feel would be a plus in its self. Or at least for me, since I seem to get in deep of the throat of the bow grip. For sure when holding a bow at full draw and aiming. One doesn't need a sharp corner to contend with. Like Nut's & Bolts has pointed out the need for rounded coiners.

By the way Nut's & Bolts. Glad to see you adding your expertise here. And posting more. you have been missed.

=========================

Now to the limb pockets. I'm very impressed with the smooth design look, and I just might be a little envious. [ Smile


========================= 


Little add on here. Since I have been shooting my Genesis Quad Fire since September. It didn't take long, for me to understand the befits of less or no nock travel. And how this shorter AtA bow seem to just to set in my hand as good as my 40 1/2" AtA bows.. With little front stabilizer weight needed. In fact one just might be surprised. How well one might make a shot, with no stabilization with this bow at time of shot. 
For the hunter I might add, it would be a out standing bow in a tree. With no front weight needed. Then while still having thoughts, of the hunter in mind. Guys with less nock travel. Means less tuning for broad heads. Your field points and broad heads should be very close, with less or no nock travel.

==========================

This is a plus on roundness. U might want to compare this picture, with the pryor Quad Fire in same area, for consideration. For what I'm trying to show and explain.[ Later


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## CNC Machinist (Sep 28, 2003)

Unk Bond,

I've got the same riser now that you have. I got my bow Sunday, and noticed the same thing on that riser. (the 45 degree corner digs into the top of my thumb). I will make sure the new risers don't do this. I also found out that we should add another hole higher up for mounting the sight. 5 holes vs. the 4 holes that are in it now.

All of this I just found out, after shooting it.

Anything else you would like changed???


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## Edsel (Oct 1, 2011)

I'm really glad this thread,...

...well,...

...simply *EXISTS.*

*The content is just substantial, and is so much more engaging to read in comparison to the typical "that's how I've done it for thousands of bows I've set up in my shop" routine which've been forced down our throats ad nauseum.*

Kudos to N&B, CNC Machinist, and Terrier for this well - thought out, substantive, and educational thread.


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## rodsedge (Jun 23, 2010)

there is just 2 darn much stuff to keep track of Don but you can handle it I'm sure. Good luck I'll be in touch---Rod


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## GenesisAlpha (Jun 26, 2009)

Unk and CNC, I talked to Don about the issue of the 45 degree angle coming off the shelf. Even with the angle gone it will be a better guide for the hand with the adding of a grip. I have been working on a grip for the bow and here are a few pics of the index side of the grip. I am making a filler addition to take up the void where the machined angle is at present. I agree would be better to take that cut off the program.



















If you both would like one, let me know. 

Bob


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## CNC Machinist (Sep 28, 2003)

GenesisAlpha,

Your grip looks nice. It doesn't look like it would fix the problem where the other 45 degree cut hits the thumb. Circled area.


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## GenesisAlpha (Jun 26, 2009)

Actually, when the thumb side of the grip finishes the way I intend it to it just might resolve the issue you point out also. I never found that area to be a problem, but I can see where it may affect some. The 45 on the index side allows your hand to slide up past the point where it should be in relation to the shelf. I told Don it makes the bow lean top toward the bow arm and the bottom kicks out away from the archer. I will send Don a finished grip to try on the bow.


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## beretta_x_trap (Jul 24, 2007)

as a cosmetic hype, i would reccomend adding some sort of a bow hook to the top of the riser that style of accessorie is really catching on these days.


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## CNC Machinist (Sep 28, 2003)

beretta x trap,

What bow manufacturers are you talking about. Could you give me an example?


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## BLan (Aug 16, 2010)

WOW, simply WOW. So glad I ventured into this thread this evening. I feel smarter simply by reading through it all, even if I was lost for some of it. Great cooperative work by all who participated in this thread. This thread has renewed my faith that AT is about Archers helping other Archers and not simply bickering back and forth.


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## CNC Machinist (Sep 28, 2003)

I got the limbs, and cams modeled. Here's the assembly with them added.









It needs a rest, string and cables now.


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## Nameless Hunter (Feb 10, 2007)

CNC Machinist said:


> I got the limbs, and cams modeled. Here's the assembly with them added.
> 
> View attachment 1242550
> 
> ...


I design and build waterjet machines with Solidworks (yawn) but this is some cool stuff.


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## CNC Machinist (Sep 28, 2003)

Hey MOTU,

Thanks for the complement. I use to work for a machine shop, and we built a Abrasive Waterjet. We used the intensifier off a used machine, a Dynapath control off an old CNC mill. We where using Mastercam for programming, and we got a post from the company you work for I believe. (Wardjet).









They now run an Omax I think. :wink:


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## Nameless Hunter (Feb 10, 2007)

CNC Machinist said:


> Hey MOTU,
> 
> Thanks for the complement. I use to work for a machine shop, and we built a Abrasive Waterjet. We used the intensifier off a used machine, a Dynapath control off an old CNC mill. We where using Mastercam for programming, and we got a post from the company you work for I believe. (Wardjet).
> 
> ...


Well, actually Ward is a competitor. My company is CNC Machines Intl. One day I need to take some SW courses so I can draw at your level.


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## CNC Machinist (Sep 28, 2003)

Motu,



motu said:


> i need to take some sw courses so i can draw at your level.


 This is my level....:set1_violent002:

I'm a beginner, who has too much time on their hands. I got the rest finished today, and mated with the riser..


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## GenesisAlpha (Jun 26, 2009)

Was working on the bow setup and grip for Dons New Bow. Still have to put my tuner rest on it but so far it is sweet. Put a string stop on the bottom to see if there was a difference, bow was the same............smooth, quiet and shock free. Set at 55# with a 8.5 brace and a 39 inch Axle, 31 inch draw. My hat is off to CNC and Don, bow was awesome to start and it keep getting better. I will be dipping the limb cups and limbs shortly. Cups will be the same camo and the limbs will be carbon fibre. New cups have given the bow longer draws and a shorter brace.


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## Kstigall (Feb 24, 2004)

I didn't think I'd see a high wrist grip on a compound for another few years. I'm glad to see it and believe one day there will be more bows made with a higher grip. I understand the vertical grip but I don't necessarily agree it is "better".


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## GenesisAlpha (Jun 26, 2009)

I have shot for the most part bows that have a very close angle to vertical wrist grip. This grip is a moderate to high wrist grip and is very, very comfortable. It gets your hand into the proper location without having to adjust. The grip I designed helps to locate the wrist into a good rotation to get that bone to bone needed or consistent shooting bow arm form. In the good hands this bow will take any national paper indoor. I have the shorter limbs and will start testing it for 3D soon. Thing is it is so sweet right now I hate to change it, the up part is I know it will not let me down for a 3D bow by design. SwEEEEEEEEEEEEEEEET!


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## Unk Bond (Aug 1, 2004)

Hello All
Sorry guys for being late for the unvailing and party. :wink: But my Email DIY tread notice's failed me.
Bob very, very nice bow grips. And I might add, your bow is looking up. Can't wait to see your limb pockets in camo.

? Bob, whats that thing-of-a-ma-jig rod. You have atached in tht bottom hole of your riser with a allen set bolt.
Hint a small round weight with a allen set. Will slide nicely back and forth on that rod. For a sweet spot back weight. If one so desires. :thumbs_up

CNC and Bob, you are making my :tongue: hang out. For a set of those stylish limb pockets. Maybe later :wink: Keep up the good work. [ Later


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## Oneida Bows (Nov 24, 2008)

Great looking bow. :thumbs_up


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## CNC Machinist (Sep 28, 2003)

Since it's been awhile for me on updated this post.
I've been getting feed back on the bows that are out to see how they are shooting. (I was told that the bow is a winner!).
So after Vegas I will be machining more risers, and keeping this thread up to date while doing that.

I keep changing the riser design, so I would like to ask what you AT'ers think about my latest design?


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## nuts&bolts (Mar 25, 2005)

CNC Machinist said:


> Since it's been awhile for me on updated this post.
> I've been getting feed back on the bows that are out to see how they are shooting. (I was told that the bow is a winner!).
> So after Vegas I will be machining more risers, and keeping this thread up to date while doing that.
> 
> ...


Very nice.

I like the new arrow shelf extension.

Lower portion of the riser is much lighter....skeletonized.

The multiple sight mount options is also excellent.

Your design is evolving nicely.


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## Oneida Bows (Nov 24, 2008)

Your work looks exellent :thumbs_up


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## strikefirst (Mar 30, 2009)

Love the grip angle!


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## Unk Bond (Aug 1, 2004)

Hello All
Very nice. 
I also like the extended arrow shelf, and the end radius contour curve .
I also like the change from horizontal cut outs .To using vertical slot cut outs, in the riser widow.

Might add, that blue color riser. Is a very pleasing color, for the eye to view. Again very nicely done. 

[ PS. I have a set of limbs, cams and a harness. I think will go nicely with it also. And a big old box for shipping [ Smile [ Later


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## Unk Bond (Aug 1, 2004)

Hello CNC and All

As a suggestion. One might add two threaded 5/16 / 24 recessed holes . As pointed out in the picture.I can think of mutable uses, for two threaded holes in this location area. [ Later


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## CNC Machinist (Sep 28, 2003)

Unk Bond,

The holes will be there just like the one you have, *I haven't finished working on the model yet*. :wink:


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## Unk Bond (Aug 1, 2004)

CNC Machinist said:


> Unk Bond,
> 
> The holes will be there just like the one you have, *I haven't finished working on the model yet*. :wink:


===

Hello All
Here you loud and clear. New you wasn't quite finished working on the model yet. But I wanted to give a early bird suggestion. :wink: [ Later


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## Unk Bond (Aug 1, 2004)

Unk Bond said:


> ===
> 
> Hello All
> Here you loud and clear. New you wasn't quite finished working on the model yet. But I wanted to give a early bird suggestion. :wink: [ Later


=
Add on computer problems ukey:

Speaking of feed back. Here is a little feed back for you. Fellow club member just left. He shot my bow with using size 500 arrows. After sighting in with my short draw length. As you might know I don't use a peep sight, just a Anchor sight. He put the 2nd and third arrow in the same hole. I said now I want to show you something. I handed him a Gold Tip XXX arrow, smiled, and said have at it.This XXX went in the same hole.Now I had his attention. :wink: [ Later


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## robin smith (Jun 6, 2011)

This looks like a real shooter what is the ata and bh?


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## robin smith (Jun 6, 2011)

CNC Machinist said:


> Since it's been awhile for me on updated this post.
> I've been getting feed back on the bows that are out to see how they are shooting. (I was told that the bow is a winner!).
> So after Vegas I will be machining more risers, and keeping this thread up to date while doing that.
> 
> ...


I am a machinist with the fed gov and I was wondering how hard would it be to miror out the top half of the bow so as to have a shoot thru design and buy the extrusion that way.


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## kyle15066 (Jan 18, 2012)

that is looking great i cant wait to see the finished thing!


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## CNC Machinist (Sep 28, 2003)

Robin,
The bow I'm shooting is 40" axle to axle, 8 1/2" brace height, 31" draw length. This bow is machined out of billet, but I don't see a problem with an extrusion, (accept for cost). My wife is also a machinist for the fed gov. Have a great day and thanks for your reply.


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## onyx48166 (Feb 9, 2011)

sweet thread


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## Gabriel McCall (Feb 8, 2012)

Terrier said:


> Thank you.
> There are two aspects in terms of asymmetric layer thickness.
> 
> 1, The stress of connection point of the two difference layer has to be same in the both material under the tension. If it is not same the epoxy has to cope with the stress difference between the two layer and the bonding will be weak.
> ...



I'm new here, but have an idea for the bow limb that split along the layers. What if one were to simply loosely "Serve" the limb so that the composite structure didn't rely solely on the epoxy between the layers, but also had a few wraps around the limb structure on the outside so that the layers were compressed together externally and not just laminated?


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## nojreyd (Oct 1, 2008)

I am not into bow design but stubled across this thread. I design machines and specialty automation for a living. An FEA analysis (static) using solidworks or even back in Mechanical Desktop/Inventor is a very powerful tool when doing designs on pieces like this. I highly recommend you learn how to use it. The key to a good riser design is having material where you need it and removing it where you don't. Harmonics/vibration of the unit is a bit trickier, but knowing how risers react on current models of bows (youtube slo-mo videos) will provide the insight needed.

Ordering custom extrusions to machine risers from will not be cost effective until you are talking about building bows in the 100's or 1000's. For a handful, you are still better off using a solid piece. Not sure what alloy you are using (6061? Or a 7000 series?) but you might want to check out 2618. Its a lot less expensive than 6061 with similar properties.

Very cool to see the work being done. My own custom riser is something I will hopefully one day do, but just not right now...


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## CNC Machinist (Sep 28, 2003)

nojreyd,
Thanks for your input. I see that you are an engineer. I would love to learn how to use the FEA analysis of Solidworks, but I only have access to Solidworks 2009 standard edition.

We are using T6061 aluminum, and we weren't ever thinking on using extrusions. As you said $$$! I will check on 2618 alloy, that's not one I'm familiar with.

And for everyone that has been following this thread, watch for more info after Vegas. (Hint...Someone that is a *really good shooter*, is using this bow).


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## SilentElk (Oct 6, 2004)

CNC Machinist, you will have a FEA tool Its called Cosmos. If my 2006 and 2011 basic Solidworks programs have it, you have it. I am sure you used it already when making the bow. Here's an interested read up of FEA I came across. http://www.clear.rice.edu/mech403/FEA/Compare_FEA_Codes.pdf

EDIT: Note though that in a basic/standard Solidworks edition you cannot test assemblies. Basically how you apply limb pressure when testing will be identical material to the riser which doesnt give the most accurate results. It will tell you with a certain degree what is good and what is wrong overall but finer points such as changing a radius slightly to optimize wont be as accurate unless: 1. You can test as the true assembly used and 2. You have correct parameters for the materials used. Limbs would be one of the more difficult. PIA but thats how it goes.


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## kylecurtis04 (Nov 30, 2010)

keep up the hard work. it all looks great.


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## Terrier (Feb 19, 2009)

Gabriel McCall said:


> I'm new here, but have an idea for the bow limb that split along the layers. What if one were to simply loosely "Serve" the limb so that the composite structure didn't rely solely on the epoxy between the layers, but also had a few wraps around the limb structure on the outside so that the layers were compressed together externally and not just laminated?


The problem is with your idea that the unidirectional fiber laminate tensile strenght is ~1800MPa and the simple twill woven laminate (so the half of fiber is perpendicular with the lenght of limb) tensile strenght is just 900MPa. So you solution is really solve the problem but this possible limb would be frail. 
The possible solution would be the really composit material with aproxx 30 difference layers so have to make the full geometry in same time by one laminating and not from difference bonded layers. The best simplier and fast solution is another epoxy resin. The Gordon composite use an older epoxy with very bad tensile (34MPa) strenght and elongation of break 6% ration (5,6). 
Example. The Epolam 5015 tensile 80MPa the elongation of break 8% = 10


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## nojreyd (Oct 1, 2008)

We buy 2618 Aluminum from Clinton Aluminum in Clinton, Ohio. We use it for various parts/pieces. Its a cast-formed aluminum with properties similar to 6061 from what I can tell. It is less expesive, and supposidly machines easier. Only available is size 2" thick or thicker, but I am guessing your stock to start is probably 2".

Also, they may be able to save you some time by waterjetting your riser profile and sending you waterjeted blanks, just a thought.

http://www.clintonaluminum.com


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## Unk Bond (Aug 1, 2004)

Hello All

Can't wait to see your new design riser harness up. 

Mean while, just received . What-cha think of my new sin-E limb pockets, with a longer AtA now. And may I say here, holds like rock. :thumbs_up Just steady, I tell's U. :wink: [ Later


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## kirktink (Jul 15, 2011)

*This Bow is a phenomenol shooter for sure!!!*



The bow is a great shooter and will be even better with the new riser,,,the weak spots are corrected. It should be even better. I'm thrilled to be associated with the company now,,,i expect us to have a pure top performing target bow as well as a great bow for hunting..

in all reality i've had 6 weeks practice now..(after a 13 year retirement from archery). I competed in the Southeastern indoor tournament this past weekend.. My goal was to shoot 57 to 60 x's.. which i did on Sunday.300 with 58 x's. (My car transmission went out on the drive to Maggie Valley on Saturday morning, and i was more worried about that than shooting hence a lower score... 

I am posting my Sunday target... I missed my first shot for score then missed shot number 31 when we moved to the high target which was at least 3 feet higher than i had practiced on. Anyway, i attribute the excellent score to the bow as i've not had that much practice for sure...hopefully i will be primed for a high finish in the nationals in a couple of weeks!

Thanks to Don and Roger for this bow that i consider better than any i've shot in the past,,,(including my national championship wins!) also thanks to carbon express for the fine shooting x-jammer 27's

Anyway,,i submit my target for your viewing..








Kirk Ethridge


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## kirktink (Jul 15, 2011)

My number 1 target is high left i got nervous and missed my first shot!!! my 2nd miss was just off the line to the left on the same target (High left)

Kirk


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## kirktink (Jul 15, 2011)

P.S. 

also thanks to Mike Lapera (Original Brite Site) for the scope and rest!

Kirk


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## Unk Bond (Aug 1, 2004)

Hello All
Very nice shooting Kirk. :thumbs_up 
Looks like U are on your way back,from your long dry spell. We are rooting the best for U, in the up coming nationals. [ Later


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## Unk Bond (Aug 1, 2004)

Hello All
Got a little heads up for U on this bow,that I just become aware of. And thought I would share with U.
Just came in from my shop lab :wink: Where I took this bow down completely. Removed the hardness system and cams intact and tied up with two electrical ties. To be ready to put them back on the riser.
Then removed the limbs and the limb pockets, in about 20 minuets. Guys I sure hant no bow mechanic. It was just a piece of cake to do this complete take down with out a bow press.

All that's needed is a alien pack a small screw driver, for the E clips.And a couple electrical ties. Oh yes, shant for get to mention my palm magnet. To ketch the E clip. 

Guys I took pictures as I took this bow down. And will post later.[ Later


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## kirktink (Jul 15, 2011)

Thanks! my "dry spell" was inactivity, retirement from competition. 13 yrs no less...time flies..

Kirk


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## Unk Bond (Aug 1, 2004)

kirktink said:


> Thanks! my "dry spell" was inactivity, retirement from competition. 13 yrs no less...time flies..
> 
> Kirk


================
Hello All
I new that Kirk "My bad." That I didn't bring my post out clearer and explain.. U know how it is. Think one thing. And then just start typing. 

Well I even for got to mention ,that have this book, that U wrote on archery. Lot of great information in this book for a archer. [ Later


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## kirktink (Jul 15, 2011)

*This is a "Bow for the Ages"!!*



Now that i've had a few weeks practice with the new "Apollo". I'm pleased to say unequivicolly that this is the most accurate bow i've ever owned. This bow is really and truly special. 

Aiming with this bow has become unreal... Don's limb design and wheel combination has resulted in reality the best shooting bow i've ever owned... In the past, i would get a couple bows from my sponsor and work really hard getting them to shoot.... the key was coming up with a tiller & stabilizer combination that would aim well... every now and then a "magic" bow would appear,,, mostly they would be run of the mill.

This bow is different however.. it is just purely awesome When i won and set records 20+ years ago, good aiming was what allowed high scores... This bow has taken that to a new level... I am getting really long pauses of "dead still" aiming. (All my past bows gave short pauses, & getting the shot to release during a "pause" was key" This bow give such long dead still pauses, that making a good shot is becoming relatively easy. 

I'm really looking forward to Louisville next week... The bow will absolutely do its job... I attribute my good shooting to the bow as at my tender age of 52, the strength of my power lifting past has faded much... When i do well in the nationals,,,, most of it can be attributed to the bow... I'm shooting so much better than my small amount of practice should have revealed.

Anyway, Thanks Don, and Roger,,,& wish me luck!

Kirk
"


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## GenesisAlpha (Jun 26, 2009)

Best of luck to you Kirk, I agree this is a very special design. Don and Roger have done an awesome job with more in the works. The limb deflection is like no other bow out there and the true vertical limb pull gives the cams a straight thrust with no lateral force. The bow gives the feeling it could be shot in mid air by itself, no forward jump and no back at you preasure in the grip............SWEEEEEEEEEEEEEEEEEEET!


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## kirktink (Jul 15, 2011)

*NFAA National indoor performance*



GenesisAlpha said:


> Best of luck to you Kirk, I agree this is a very special design. Don and Roger have done an awesome job with more in the works. The limb deflection is like no other bow out there and the true vertical limb pull gives the cams a straight thrust with no lateral force. The bow gives the feeling it could be shot in mid air by itself, no forward jump and no back at you preasure in the grip............SWEEEEEEEEEEEEEEEEEEET!


The bow shot great, I had scored several 60x rounds the week before leaving for the match and was very confident i would at least be in the shoot off.. I decided to change nocks on thursday for safety and shoot each arrow a time or 2 to be sure of alignment. during this test my release broke! I was up all night thursday trying to get another one going.

I was shooting a little finger HT2000 that Jerry (Carter) no longer makes .(The little finger sear assembly broke completely in two! I had an extra one that didn't close properly so took the little finger sear out of it,,,turns out it was not the same length, so in effect i had no release to shoot..(At least not one i had been practicing with).. Needless to say i shot poorly Sat with 49x 300.. & lucky for that.. Sunday, i tried a different one and lost 2 in the floor, but 50x.. (290)

I was very disappointed to say the least. I hate to complain as i know many shooters would be thrilled to shoot just a 300 with any x count. The Apollo, (If this is the name Don decides to keep for the bow) has no bow that can out shoot it. If any of the 60x shooters had this bow, the would have won the shoot off. 

Kirk


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## Unk Bond (Aug 1, 2004)

Hello All

Any up dates on this new design riser.

===============

Here some new bow pic's I recieved from Bob. Thought I would share with you guys. [ Later


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## pinski79 (Jan 23, 2010)

awesome


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## Unk Bond (Aug 1, 2004)

pinski79 said:


> awesome




==================

Hello All
" awesome " Is a good word to describe this bow. I have the target model. Like you say its awesome and very quiet .

From what I experanced with this bow. And I have had it for quiet some time now. There is no forward jump to the riser when the shot is made, and no bow hand shock. And takes very little front tabulation as a target bow. As a hunting bow. I for one, wouldn't even use a front stabilizer, if hunting from a tree.

Might add here, this bow has no nock travel. How can that be you may ask. Well I asked the same thing. Even knowing and seeing that, after shooting the bow. it didn't have knock travel. 
Well it took a while for that to soak in I assure you. :wink: And after several question I did ask. 
It came down to how the limbs were design, and how the 2 cam's axles traveled. At time of drawing the bow to anchor, and after the shot was made. You see this bows limbs bow out, as the two cam's travel towards each other. Not out like the bows on the market at this time. 

Encloseing, might add here. You hunters useing broad heads . You will have very little tunning from your field point setting. Bragging, heck fire no. Just stating a fact. :wink:[ Later


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## CNC Machinist (Sep 28, 2003)

Dale,

Who jammed a stick up your butt?:angry: You have made 3 post, all negative commits about people who clearly have ideas to post in this DIY forum.

As for a crutch for people who can't shoot.........I have 6 Martins, 1 Hoyt, 1 Mattews, 1 Barnsdale, and one I made for Don Kudlacek. ALL OF MY
BOWS I CAN SHOOT EXCELLENT WITH. So, what's your problem???

If it wasn't for inventive people, we would be flinging wood arrows through a crude recurve bow.

Just saying.......

No hard feelings:wink:


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## REDVANES (Nov 27, 2009)

nuts&bolts said:


> I suggest a Finite Element Analysis.
> 
> Looks like you have quite a few holes in the sight window area.
> 
> ...



lol what a tool!...


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## Oneida Bows (Nov 24, 2008)

This bow looks awsome, looking forward to hearing and seeing more:thumbs_up


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## z7MagnumFreak (Aug 6, 2012)

Awesome!


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## DRock (Sep 7, 2012)

This is the best thread I have read so far on AT, it was very cool to see it come to fruition.

I myself work for an Aerospace R&D company funded by the government through NASA and the military and enjoyed reading all the technical posts as I now have a better understanding of how a compound bow is able to store so much potential energy. 

I do have to say though that it is disheartening to see the negative posts in here...I suspect that they come from lesser intelligent individuals who do not share the same drive to not only accept and understand what is currently known about bowhunting but have motivation to innovate and do things differently.

That...my friends...is the difference between the sheep and the Shephard.


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## SARASR (Oct 30, 2009)

REDVANES said:


> lol what a tool!...


If you refer to nuts&bolts recommendations then you sir are the "tool" he would be one of the most respected gents on this forum, who does have an impressive bit of knowledge, and freely shares it to help others. Try an advanced search of his handle, 
then let us know how that crow tastes.


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## brownback (Aug 15, 2006)

This has been great reading. Very glad you gents share your knowledge I know Mr. Bond has a lot of knowledge and it is great to see others here the same!


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## drillbit (Oct 26, 2009)

Awesome thread great looking bow and definitely peaked my interests...I've been a cnc "jobsetter" and operator for 3 years and have just started learning to model on Autocad and am also starting school in January to be a mechanical engineer with a minor in machine tool automation so this definitely appeals to me thanks for posting this.


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## Scojen (Jul 17, 2012)

it looks as if this thread is been silent for a while I would like to know if you have taken the bow back apart and check the alignments of the limb pocket holes cetera the reason why I ask is when you set up to run another riser you may want to leave about 0.90 of material overall then have the riser aged then do the final machine work this will help to alleviate any stress risers stilli floating around in the riser if you need you G code for the next 1 I am more than happy to help 

Scott


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## CNC Machinist (Sep 28, 2003)

I would like to give an update on this thread. I was unable to continue working on building these bows for Don. I had high hopes that *Kirk Ethridge* was going to do great things with his bow at Vegas, Indoor Nationals. And the bow would be looked at as a *WINNER*. _I think Kirk is now a staff shooter for OK Archery._

If any of you are interested in my Solidworks model PM me and I can send you my latest, last design.

I do want to thank everyone who contributed to this thread, I think a lot of people here on archery talk enjoyed this thread.


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