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Main Boards => PowWow => Topic started by: Holm-Made on July 08, 2008, 04:13:00 PM

Title: aluminum Bow Form questions
Post by: Holm-Made on July 08, 2008, 04:13:00 PM
I might have the opportunity to trade a bow to a machinist in return for having him machine an aluminum form on his CNC machine for me.  I don't intend to change my osprey longbow form as it has served me well for several years and thought it would be nice to have a form made that I will never have to replace.  

Does anyone use an aluminum form and are there any considerations to be aware of.  Does it transfer heat to the lams differently, etc?  
Thanks,  Chad
Title: Re: aluminum Bow Form questions
Post by: TimZeigler on July 08, 2008, 06:41:00 PM
Chad, I haven't come up with any reason not to.  I've thought about the idea myself and don't think it would be hard at all to get a form that would last a lifetime.  I think a take down press would be my choice due to the weight that might be involved with a one piece set up.  Tim
Title: Re: aluminum Bow Form questions
Post by: Holm-Made on July 09, 2008, 05:09:00 PM
TTT
Title: Re: aluminum Bow Form questions
Post by: Gordy on July 09, 2008, 05:35:00 PM
Sure would be a lot easier to mount clamps to or lay in a press. Imagine mounting angles along the form halves with a weld nut or thread through the plate to use for clamping.

You'll need to get the data from your current form reverse engineered into a CAD program to utilize the CNC.....or maybe this guy already has a means to digitize your parts to program from.  (?)

One easy way to get this done is trace your forms 1:1 on gridded paper. Then if you sent it to me I could model up your form halves pretty easily in Solidworks.

Maybe I should start a form modeling service......hhhhhhmmmmmmm    ;)

BTW - aluminum is an excellent heat conductor and heat dissapator.  I'd think you'll want to use 6061 instead of cheaper aluminum as well.
Title: Re: aluminum Bow Form questions
Post by: Gordy on July 09, 2008, 06:00:00 PM
Well, I got the first half done.   ;)   Just a visual to show you how it can be done and show you the clamp idea.
Gotta go pick up kids but will check back in later.

(http://img.photobucket.com/albums/v431/TimDougherty/Archery/chadsform.jpg)
Title: Re: aluminum Bow Form questions
Post by: Bucksnort101 on July 09, 2008, 11:57:00 PM
Hey Chad, give Dave Dwyer a call about the aluminum press. He had one made for his last bow design, the Duantless Longbow. I'm sure he could give you pointers and suggestions.

P.S. How's that Chronograph working out? Did anything hit 300+ FPS:)
Title: Re: aluminum Bow Form questions
Post by: Holm-Made on July 10, 2008, 12:48:00 AM
Greg, I'll see Dwyer at Horicon this weekend.  I'll ask him.

Gordy, I think I'll stick with the air hose method as it works great.  What is 6061?  Is it a top grade of aluminum?  Chad
Title: Re: aluminum Bow Form questions
Post by: Gordy on July 10, 2008, 09:59:00 AM
Yes, 6061 is more of a tooling grade aluminum.

Don't you need something to hold the form halves together ?

Maybe I over did the clamps !   ;)
Title: Re: aluminum Bow Form questions
Post by: Pluck Yew on July 10, 2008, 01:34:00 PM
Chad, Keep the thread going ..need the info...solidworks.. what other programs would work?  :confused:

Shawn..
Title: Re: aluminum Bow Form questions
Post by: HalfRack on July 10, 2008, 06:58:00 PM
Wait a minute, I thought I was the R & D guy for Holm Made Traditional Bows?   :)  

(http://i179.photobucket.com/albums/w297/mrehnelt2/FormsAndForms.jpg)

Basically any old CAD package that exports a .DXF file will do.  The trick is getting a good CAD guy to smooth out the transitions between the radii, the rest is easy.

However this is done, you need to at least have the guy plot out something full scale before you start making aluminum chips, and hold it up against the old form, even half or a quarter of the form would do.

Chad or Shawn let me know if I can help. Chad that .DXF I sent you some time ago would be a good one to test to see if the guy can read it into his software. The more sophisticated CAM packages could work with solids files like .SAT or .STP, there is a solids version of .DXF too.

-Mike
Title: Re: aluminum Bow Form questions
Post by: Holm-Made on July 10, 2008, 10:19:00 PM
I have a shoot to attend this weekend.  I'll get a hold of "my guy" next week.  Oh wait a minute Mike, your "my guy".  Sorry,  Chad
Title: Re: aluminum Bow Form questions
Post by: Pluck Yew on July 10, 2008, 10:21:00 PM
Mike, I will wait till after this weekend..chad will have more info and I will talk to my tool-maker friend..oh I thought you were the R/D guy for Holmmade bows.. I think you should re-negoetiate..  :notworthy:  

Shawn..