# Draw Board in JAVI technique



## oldglorynewbie (Oct 17, 2006)

Simple device that you make yourself to let you safely draw your bow while not holding it. You'll need a boat winch, a pipe flange and I used a 6" nipple. You can pick up the parts for next to nothing.


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## jcs-bowhunter (Jul 7, 2007)

oldglorynewbie

That looks pretty straight forward. Thanks for the picture and description. However, I am fairly weirded out by the fact you have the exact same dining room table and chairs as we do!

Thanks Again!


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## CWG (Nov 20, 2003)

Ok.....how do you use it?
Stick the bow on, crank it back to where the cams roll over, granted.
Then what? You look to make sure both cams (binary) are both at the same point?
And if they're not? Whats the trick to get them the same? Looks like a fun thing to add to my bow tweak stuff


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## Spotshooter2 (Oct 23, 2003)

Once you have the bow drawn back and checked the cams for timing, if they aren't correct then you are going to have to put it in a bow press and twist one of the cables to get them in time.


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## oldglorynewbie (Oct 17, 2006)

Spotshooter2 said:


> Once you have the bow drawn back and checked the cams for timing, if they aren't correct then you are going to have to put it in a bow press and twist one of the cables to get them in time.


Correct. Unless it is a Guardian or Commander of course.:wink:


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## boogeyman (Oct 17, 2007)

notice the turnbuckle for fine adjustments.


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## oldglorynewbie (Oct 17, 2006)

Good eye boogey man. I forgot to mention the turnbuckle.:embara: Really helps you get draw specific. You can't see it in this pic but I have marks on the board denoting the draw length.


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## Ohio_3Der (Jul 19, 2002)

*finer cranking*

If you go to a smaller diameter rope you can get less movement per click to put a little more preciseness into the crank. Plus, a spool with just enough rope on it to work is going to help out also. The smaller you can make that spool, the less rope you'll take up per click. If the spool is to big, chances are better that the wall on the draw cycle will be in between clicks. 

I've found though, after using my own board, that you can time/tune away on the draw board, but once you take the bow off the board and shove your hand up in the grip instead of a nice round peg that you'll need to time it manually anyways. Some people will say that you'll only get close on the draw board and that you'll have to fine tune by hand anyways. Well, I can rough tune most bows by eye to get them close enough to start fine tuning so why have the draw board at all for tuning? You can, however, really get a handle on measuring draw length on a board though, and I still sometimes use mine for that.


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## oldglorynewbie (Oct 17, 2006)

All true... you can also check bow poundage with the draw board as well.


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## Bellows1 (Oct 19, 2003)

Here are a couple with bows in them.

Nuts&bolts, WWG (I think) and Tbailey.


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## soonerboy (Sep 6, 2004)

I use a strap instead of a rope and I feel it makes a lot more consistant readings.


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## CaptPete (Nov 27, 2004)

I built a draw board that looks just like the 3rd picture above. When I "draw" the bow(Hoyt), the bow rotates or turns slightly on the peg. When I check the drawstop timing, it shows that the top cam is under rotated. If I pull the back(take the rotation out it) so it is sitting straight on the board the timing is right on. When I physically draw the bow(bow in hand), the timing is perfect. Do I need to tie the bow down so it can't rotate? Also I hooked my Hansen hanging scale between the rope and bow string. I get a reading that is 3-4 lbs. less than when I using the scale from the hanging postion. Why would that be? 

Kevin


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## bowfisher (Jan 21, 2003)

*bump*

ttt


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## KingOfAllThings (Apr 14, 2005)

I cut a groove in my crankboard, and mounted a yardstick in it, so that the "0" point is at the far side of the post (measuring actual draw). Then, I have a bow scale on the cable. That way you can plot force curves as well.


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## Rchr (Jul 3, 2003)

The only thing that I can add is that when you build it make the peg of center. The peg that I use on my bow is a hook and that hook (because of its shape) can be turned. 
Reason; this will simulate your bow at full anchor. Your bow hand and your release are not on the same plane. Your bow hand is slightly lower. Believe me or not but that slight change will change the timing of the wheels. 
Doing the adjustment without the offset gets you very close but not as close as you can get.
If you look at one of the pics where the bow is at full draw on the drawboard you can see how the bow is being pulled slightly upward.

A mechanical engineer friend of mine built my draw board in 1992 and I have been timing bows since then. 

Rchr


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## nuts&bolts (Mar 25, 2005)

That's why I built my draw board so the bow would be vertical.

The pipe nipple is slightly below the level of the workbench top.
The winch is mounted on top of the workbench top.

The centerline of pipe nipple to the bottom of the winch
should be about 3-4 inches, if folks want to rotate their
draw boards sideways, so the bow is vertical.

You can add a wooden peg so the rope has to travel
over the wooden peg, in order to get the appropriate
angle on the winch rope.

When the bow is vertical in a draw board,
gravity helps to keep the bow closer to vertical.

Cam timing is all about the string angle 
in relation to the bow riser angle.

The bow riser angle (close to vertical)
affects the angle of the cables (close to vertical).

So, if you have a 2x4 single board draw board,
just rotate it and clamp it to the dining room table
or a workbench.


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## Rchr (Jul 3, 2003)

Rchr said:


> The only thing that I can add is that when you build it make the peg of center.
> 
> I am sorry this should read "off center".


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## leadsled (Mar 9, 2006)

*Draw board*

Here is a picture of my draw board. It was made out of a garage door opener (worm drive), has an integral attachment for a Cordoza bow scale, and is run by a Makita drill. This is very precise.


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## bowfisher (Jan 21, 2003)

Very nice!!


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## leadsled (Mar 9, 2006)

Thanks Bowfisher. I know it's a lousy picture (too mush stuff in the background).


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## acal (Jan 13, 2003)

Rchr said:


> The only thing that I can add is that when you build it make the peg of center. The peg that I use on my bow is a hook and that hook (because of its shape) can be turned.
> Reason; this will simulate your bow at full anchor. Your bow hand and your release are not on the same plane. Your bow hand is slightly lower. Believe me or not but that slight change will change the timing of the wheels.
> Doing the adjustment without the offset gets you very close but not as close as you can get.
> If you look at one of the pics where the bow is at full draw on the drawboard you can see how the bow is being pulled slightly upward.
> ...


Do you have a picture of your board, in particular the hook ?


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## leadsled (Mar 9, 2006)

I agree, mine is offset for the same reason. It was designed by a machinist that works for Lockheed.


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## flybyjohn (Feb 4, 2006)

I might be missing something here but unless you add torque in the bow handle by pulling the bottom part of the grip towards yourself while drawing and at full draw, the bow will be in the same position on a straight draw board as it is in your hand. In other words, if there is not torque being added to the grip by your hand and at full draw if you drew a line staight down the axis of the release, then that line will go staight through the point in the center of pressure in your bow hand. The release acts as a hinge point, creating no torque and your bow hand is supposed to be holding the bow without torque and so the only two forces on the bow in a free body diagram are going to be equal and opposite each other. 

Think of two long rear wheel drive trucks in two separate lanes on the highway come to within 100 feet of each other going separate ways. Hook the front bumpers up with a chain and then back the trucks up to get the chain tight and then keep backing up. The truck front ends will turn towards each other, creating forces equal and opposite each other.

I may be way off base here but this is the way I have always understood forces. Now your bow hand may be torquing the bow and this is something you may need to fone tune for if this is the case.


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## Rchr (Jul 3, 2003)

flybyjohn said:


> I might be missing something here but unless you add torque in the bow handle by pulling the bottom part of the grip towards yourself while drawing and at full draw, the bow will be in the same position on a straight draw board as it is in your hand. In other words, if there is not torque being added to the grip by your hand and at full draw if you drew a line staight down the axis of the release, then that line will go staight through the point in the center of pressure in your bow hand. The release acts as a hinge point, creating no torque and your bow hand is supposed to be holding the bow without torque and so the only two forces on the bow in a free body diagram are going to be equal and opposite each other.
> 
> No, in theory maybe, if you look at post #11 you can see how there is some upward tension. I have checked to see if it made any difference in the timing and it did. If you check the position of the cams with a ruler you can measure the distance is off by a 2 -4 mm from being perfect in timing/synchronization. Don't trust your eyes, actually measure.
> Acal, sorry I never got back with you about the picture of the drawboard but I am not home I have been out Texas for a few months and will continue to be so until the end of March, (I hope, unless I get extended/mandated to stay some more). You wrote me a PM once and I forgot and erased my PM's and lost yours. Again I apologize for that and if you PM me again I will save it until I can either go home and get it or if someone from back home comes over here and they can bring it to me. I am going to need it I have a new bow coming.
> ...


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## archer58 in pa (Jan 3, 2007)

If I understand this correctly. You're saying that the winch/attachment should be BELOW the center line of the board (PEG holding the bow).
As if it is pulling slightly UP??? This will match ME drawing the bow more closely that if the peg and winch rpoe are in line?

Did I get that right??


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## Rchr (Jul 3, 2003)

The peg holding the bow (grip) should be below the winch-line pulling the bow string (nock pt.).


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## archer58 in pa (Jan 3, 2007)

Rchr said:


> The peg holding the bow (grip) should be below the winch-line pulling the bow string (nock pt.).


Approximately how far? Looks like 2-3 inches.


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## Rchr (Jul 3, 2003)

It depends it might vary a little bit from one bow to another. My friend just bent a bolt into a "J" shape and that gives you room to adjust. Most bows will have a very similar distance. I also don't use a winch it is actually an all thread. 

Rchr


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## ia bhtr (May 22, 2002)

*got a ? on drawing boards*

reading this I see a couple different set ups , one where the winch is set up straight behind the peg the grip sets behind ( bow seems to roll off of verticle this way ) and the peg for the grip being below the level of the winch much like a shooter would hold the bow , this seems better to me ......... but now the question , " IF " you were to use 2 contact points for the bow , say rollers set so they set right in each limb pocket equally , thus elliminating the bow wanting to lean top back or bottom back depending upon how you got your winch/front peg set up centered , to me this should allow for synching the cams closer to the way the bow is actually hand held ......... am I off base with my thinking or does this idea have some merit ?????????


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## Rchr (Jul 3, 2003)

Yes. The thing is that the draw board will be a little bigger because it will have a "T" shape. You must also make the "T" arms adjustable so that it can be adjusted to the different shapes and length of the different risers. I also have one like this that another friend made for me (It is a copy of one made by Apple). 

Rchr


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## JAVI (Jun 19, 2003)

You guys get way too technical  no matter how hard you try you will never completely duplicate the hand pressure and its effect on cam timing.. I use the board/Hooter Shooter for roughing in the cams and then creep tune to me... Anything else is a waste in my opinion:wink:


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## Rchr (Jul 3, 2003)

*Sorry Javi*

Sorry Javi but I disagree doing this increased my scores and the scores of others(by at least 1--3pts). You will be surprised at the difference it could make. Once my bow was out of synch and I hadn't really noticed it my groups were bigger than my usual and couldn't get them smaller after a week or so of trying to correct my form I decided to check the timing and sure enough it was out of time. Fixed it and my groups were back to normal. Let me add that after I check the timing on a bow, I will have the person draw and I will eyeball the timing on them just to see if it was right for them. 

Rchr


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## JAVI (Jun 19, 2003)

Rchr said:


> Sorry Javi but I disagree doing this increased my scores and the scores of others(by at least 1--3pts). You will be surprised at the difference it could make. Once my bow was out of synch and I hadn't really noticed it my groups were bigger than my usual and couldn't get them smaller after a week or so of trying to correct my form I decided to check the timing and sure enough it was out of time. Fixed it and my groups were back to normal. Let me add that after I check the timing on a bow, I will have the person draw and I will eyeball the timing on them just to see if it was right for them.
> 
> Rchr


Hey if it works for you go for it... 

That's the beauty of archery tuning; there is no right or wrong only opinions and results...

Just like advancing the top cam on a Hoyt... I've never needed to do it... but I find string center before I start...


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