# CNC your own bow?



## baller (Oct 4, 2006)

Would be hard to copy anything currently out there without come sort of copy right or trade mark infringement. 

If anyone were to mill their own, it would have to be some sort of original design.


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## nakedape (Sep 28, 2015)

It's not for resell,
you can copy any riser for your own personal use.


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## zal (May 1, 2007)

I've seen a mate do all kinds of parts for bows with his own CNC machine, but he stopped at making a riser. According to him, it just wasn't worth the hassle or time/cost as a good quality aluminium blank cost about same as ready riser, if you buy only couple at time. He did some modification work for other bows, and machined my Axis to ILF-fitting.

I'd go for something with similar pocket construction as PSE X-factor/X-appeal.


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## SHPoet (Nov 13, 2009)

baller said:


> Would be hard to copy anything currently out there without come sort of copy right or trade mark infringement.
> 
> If anyone were to mill their own, it would have to be some sort of original design.


Get one of Chinese knockoffs and copy it. What's good for the goose.....


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## stick monkey (Mar 9, 2015)

I'm pretty sure that with patent infringement laws in the U.S. ... you would be found guilty.


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## Mr. Roboto (Jul 13, 2012)

Our court system is such that all you have to do is convince the jury/judge to believe you. It has nothing to do with right or wrong.

But as for Patents. First is there a patent on that riser? If no - copy to your heart's content. Is there a patent about a specific feature on that bow. If no, then copy to your heart's content. If there are patents, look at the claims. That is the key element of the patent. Start with claim number 1 the main one. Make a change in your copy that keeps you from violating the "exact" wording of claim #1. Then look at claim #2, and so on. Violating lower order claims while not violating higher order claims won't get you sued. Note the exact wording. The law doesn't go by the intent of the wording, it goes by the exact wording. If the wording has numerical dimension, than make outside the dimension. If it has a range, make outside the range. If it has a material, make it from a different grade of material.

The key thing about patents is that they don't prevent people from making copies of your product. All it does is give you a right to sue card. If the person that has the patent, and feels that you are violating the patent. They will first send you the scare tactic letter informing you that they have a patent. That is step one, they all do that. In fact, they do that to people that are not violating patents. Its all about fear and control.

Then if they still believe you are violating their patent, they have to sit down and decide, if it is financially worth their time and effort to sue you. Patent Attorneys charge about $400 per hour. So one has to decide is it worth the expense of suing vs what they can get out of it. Most companies won't spend the money to sue someone making a copy of their product. Its not worth it financially (other then sending the scare letter). 

Now if someone was to make a business selling copies, and the patent holder sees that the lost revenue justifies the lawsuit, then they will initiate the process.

But they have to know for sure that the copy is in fact violating the patent. Remember earlier, if the copy had enough changes that it didn't violate the major claims in the patent, they will have no case and it will get thrown out.

So bottom line, if one wants to make a copy of a riser, and make changes to make that riser work better for them as opposed to having to settle with what the original make thinks is the best, then go for it. Most likely no one is going to know that someone made a copy, or even do anything to stop it.

Businesses are in business to make money. They are not going to waste money going after someone to make no money off of.

But, in this country, there are those that will cut their nose off to spite their face.


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## huckduck (Nov 24, 2014)

Mr. Roboto said:


> Our court system is such that all you have to do is convince the jury/judge to believe you. It has nothing to do with right or wrong.
> 
> But as for Patents. First is there a patent on that riser? If no - copy to your heart's content. Is there a patent about a specific feature on that bow. If no, then copy to your heart's content. If there are patents, look at the claims. That is the key element of the patent. Start with claim number 1 the main one. Make a change in your copy that keeps you from violating the "exact" wording of claim #1. Then look at claim #2, and so on. Violating lower order claims while not violating higher order claims won't get you sued. Note the exact wording. The law doesn't go by the intent of the wording, it goes by the exact wording. If the wording has numerical dimension, than make outside the dimension. If it has a range, make outside the range. If it has a material, make it from a different grade of material.
> 
> ...


or you could get those lousy people who claim to be patent holders and in reality are just fishing for idiots


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## Delw (Mar 28, 2014)

nakedape said:


> I met a new archer at my range who is a machinist.
> 
> He asked me if there are open source CNC files for an oly riser.
> 
> ...


Any machinist thats competent can make a bow riser recurve or compound, its not that difficult, changing the riser to different specs are pretty easy as well. the cams arent that difficult to copy either changing them for a different design isnt that hard if you know what your trying to achieve. nice thing about cad/cam software is you can make some changes try it and if it doesn't work change it

a competent machinist can copy a riser in a matter of a few hours(with standard inspection tools that he should have being a machinist) then machine it. if you have a cmm you can do it in mins. then if you have decent software you can make any changes you want for looks grip size etc etc

I was going to make a compound target bow using bowtech cams and limbs just because my daughter is a bowtech freak and they didnt have a target bow at that time. Luckily for me they came out with the fanatic one, during the time I was designing it.. I say lucky cause its alot of work. Yeah it would have been fun to do with her as she runs machines also, yes it would have been just as good if not better that what you can currently buy. but the cost and time factor would have been huge. which I dont have a problem with I just cant justifying recreating the wheel when it can be bought . with time fixtures and material plus cams limbs customer made strings and cables I was probably looking at $2000-$3000, for a recurve riser your looking at about 1k time and materials
your biggest cost is going to be the chunk of material 6061 doesnt work and it sucks. 7075 is best. but its 4-5 times the price of 6061.
we buy large volume of material every week so I would have gotten it at a pretty good price. most guys will pay about 200-400 bucks for a chunk if not more(rough guess). IN billet/blocks the direction of the grain is important also. 
you will have to plan what limbs to use in advance and cut those limb pockets to the dims on a bow that is already using those type of limbs not to mention you might have to have a string custom made. 
if you count your time in for the machining your looking at 3-10 hours run time on a cnc plus set-up. of course this depends on the level of skill the machinist has and the types of machines that are avail to him or her.
I'm fortunate cause I got mills up to 80x47x35" inch travel with full forth axis if I elected to go that way.
the biggest problem most machinist will have is making the grip just right, if you cant program surfacing/3d or have no way to program surfacing dont even attempt it as you might have made a pretty riser but your grip may not work for you.
true positions/squareness are extremely critical in making a riser due to the fact the risers are long, just .001 wrong indicating a riser for the next operation can make a huge difference at the other end. limb pockets would suck if they weren't square , perpendicular and at the correct angle
the machinist will also have to make fixtures its a must, your not going to just clamp it on the table with clamps so your looking at another 200+ in material and 5-10 hours of time making your fixtures to hold the riser so you can machine it.

getting a open source code ie a program that's already written is just downright foolish for the simple fact that #1 you have no idea what your making, you have no idea if its going to work with the limbs your using(chances are 99% it wont be correct). #3 you have no idea about the shape of the grip they used and how it fits. and you just wasted 300 bucks in material not to mention time if you can get the drawings at least you can modify them to your liking and just run the grip section on some small chunks for testing. remember one thing on open source stuff anyone can draw a pretty picture with today's software , but not very many can apply tolerances and other key factors into the actual part.
if you have doubts in what I said look at all the guys trying to machine ar-15 lowers, uppers carriers and bolts from all the junk open source/programs out there, not to mention all the prints that were measured with a pair of calipers and oh thats close enough attitude.

Delw


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## grantmac (May 31, 2007)

Delw, 

Clearly you have a machining background, bit not much recurve experience. 

For target use recurves use limbs made to a fairly consistent standard that is interchangeable across manufacturers. Likewise most bows have grips which are interchangeable as well. This makes designing certain aspects quite easy. But due to their nature you have to be extremely precise on where the limbs seat.

Also 99.99% of recurve risers are made from 6061 and it works just fine I promise.

Grant


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## zal (May 1, 2007)

grantmac said:


> Also 99.99% of recurve risers are made from 6061 and it works just fine I promise.


Well, not quite. 7075 is also very popular (most Korean bows) and 6082 (most Italian bows, Merlin bows etc.). 6082-T6 is much cheaper and easily available here than either of the two usual options. But still you are looking at least around $200 for the billet. You can try to order from China (Alibaba) as a commercial sample but you can't be sure what you get, and they are much more customed to delivering metric tons rather than small samples.


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## Delw (Mar 28, 2014)

grantmac said:


> Delw,
> 
> Clearly you have a machining background, bit not much recurve experience.
> 
> ...


I have absolutely no recurve experience. and my compound experience is limited.
The reason I dislike 6061 is due to its soft, holes wear out fast and anything with lots of pressure over time tweaks a little. That being said hard annodize will make 6061 surfaces a tad harder on high wear/use areas.
I had no idea about that grips good to know as well as the limb being a standard so to speak from manufacturer to manufacturer. makes it a little easier for the person who is machining there own bow.


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## Mr. Roboto (Jul 13, 2012)

I have always wondered at some of the hidden reasons behind the dislike of barebow/Traditional/Longbow as compared to Olympic Freestyle bows and Compound bows in competitive tournaments.

I think part of this is the manufacture of the bow. Most people don't have the tools or know how to make a compound bow, or an aluminum riser Olympic freestyle bow. But you do see that there are a lot of home made barebows/traditional/longbows out there.

So is there a hidden bias that says you can't be competitive unless you are shooting a CNC machined riser with carbon fiber limbed bows? As time goes on, people have moved from wood to metal, have developed and honed there skill at shooting and new generations see the performance of these shooters with the new materials, and want to shoot the same thing, and they get better, and so on and so on, and develop the perception that hand made hardware is inferior to the marketing hype of corporations making high tech gear that says its the gear and not the archer and yet it is the skill of the top archers that are the ones that do all the work, and not the equipment.

So if there is this bias against home made bows being inferior to anything CNC made, then people move away from learning how to make their own bows. They don't learn how to make a aluminum riser, they don't learn how to make a better mouse trap. A skill set is lost.

So as time goes on, we start to get these strange questions, can someone make their own CNC riser. And people look at them like they are from Mars.


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## SlinginwithSage (Aug 1, 2012)

I would say that Dewayne Martin and Calvin Smock of CDArchery are from Mars..And I say that in a good and admiring way!


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## beefstew27 (Mar 18, 2008)

Mr. Roboto said:


> I have always wondered at some of the hidden reasons behind the dislike of barebow/Traditional/Longbow as compared to Olympic Freestyle bows and Compound bows in competitive tournaments.
> 
> I think part of this is the manufacture of the bow. Most people don't have the tools or know how to make a compound bow, or an aluminum riser Olympic freestyle bow. But you do see that there are a lot of home made barebows/traditional/longbows out there.
> 
> ...


I don't think there is any bias against them, it's just that as technology develops old things fade away. If you were entering a speed shooting pistol contest, would you rather have a lock and wheel pistol from the 1500's or a modern pistol designed for speed shooting? Consistency, vibration control, adjustability all go into effect, and those are things that you just don't get with wooden risers, that you do get with moder aluminum ones.


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