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Main Boards => PowWow => Topic started by: sbschindler on July 28, 2008, 12:02:00 AM

Title: what is a foam cored limb
Post by: sbschindler on July 28, 2008, 12:02:00 AM
I have been hearing about limbs that are "foam cored" what is this foam stuff,   :help:
Title: Re: what is a foam cored limb
Post by: amar911 on July 28, 2008, 12:06:00 AM
It is a bunch of little glass balls in a resin material. The foam is very stable and consistent and gives the limbs an incredibly smooth draw. I just shot some of my Morrison foam core limbs again this evening. The foam can be worked into the same shapes as other core materials like bamboo and hard woods. It is definitely not what you think of when you hear the word "foam" and think of Styrofoam or the stuff that comes out of a can!
Title: Re: what is a foam cored limb
Post by: Benny Nganabbarru on July 28, 2008, 03:18:00 AM
Are foam-cored limbs offered with exotic wood veneers?
Title: Re: what is a foam cored limb
Post by: mooseman76 on July 28, 2008, 05:10:00 AM
Check out the thread titled "Morrison Dakota" there is a foam cored limb with Kingwood veneers.  Looks really nice, but most I've seen have carbon backing and black glass on the belly with no veneers...Mike
Title: Re: what is a foam cored limb
Post by: leatherneck on July 28, 2008, 08:11:00 AM
I have the Morrison foam cores with Bacote on the front and back of my limbs. No carbon. Bob says the carbon doesn't do much for the recurve limbs but does help out the longbow limbs. Give him a call and he will surely explain them to you. It's pretty neat stuff.
Title: Re: what is a foam cored limb
Post by: sidebuster on July 28, 2008, 08:27:00 AM
Where do you buy foam core material to make the limbs?  How do you know what to ask for as far as poundage of the bow you will make?
Title: Re: what is a foam cored limb
Post by: leatherneck on July 28, 2008, 08:29:00 AM
Side-Better call Bob Morrison on that one.
Title: Re: what is a foam cored limb
Post by: SteveB on July 28, 2008, 08:38:00 AM
Bob has spent a lot of time getting the formula right. I personaly would not ask him to share too much hard earned and costly proprietary info.

Steve
Title: Re: what is a foam cored limb
Post by: Izzy on July 28, 2008, 10:15:00 AM
I ordered a set for my Zipper at Denton hill and they will have bubinga veneers.I noticed the noise reduction or total lack there of.Very smooth draw as well.I guess its been around for a long time and not new tech like I thought.
Title: Re: what is a foam cored limb
Post by: amar911 on July 28, 2008, 10:31:00 AM
Here is a link to the patent with the patent claims. It has some of the best information you can get without asking for proprietary information like how Bob Morrison builds his limbs. You can see that the foam was invented by Hoyt and used in the Hoyt limbs quite some time ago. The patent talks about the tiny glass spheres in the resin matix. Using that and a set of limbs from Morrison or WinEx, I guess you could sort of reverse engineer the limbs, but it will take some trial and error. I am not sure where the material can be purchased.  http://www.google.com/patents?id=h7oyAAAAEBAJ&pg=PA1&lpg=PA1&dq=United+States+Patent+4819608&source=web&ots=Mkt6HuKzS8&sig=EiF-yREkAIs-KLWwUxn956ZBKhs&hl=en&sa=X&oi=book_result&res num=10&ct=result#PPA1,M1 (http://www.google.com/patents?id=h7oyAAAAEBAJ&pg=PA1&lpg=PA1&dq=United+States+Patent+4819608&source=web&ots=Mkt6HuKzS8&sig=EiF-yREkAIs-KLWwUxn956ZBKhs&hl=en&sa=X&oi=book_result&resnum=10&ct=result#PPA1,M1)
Hope this helps.

Allan
Title: Re: what is a foam cored limb
Post by: mike g on July 28, 2008, 10:54:00 AM
Can Bob....
Make a set of limbs for any Take down Recurve....?
Title: Re: what is a foam cored limb
Post by: amar911 on July 28, 2008, 10:54:00 AM
Here are a couple of links that talk a little more about syntactic foam and even show some scanning electron microscopic photographs.  http://en.wikipedia.org/wiki/Syntactic_foam
http://en.wikipedia.org/wiki/Glass_microsphere

This is a link to someone who sells the foam, but I don't know if it is the kind that is useful in bow limbs. They might be able to give you more information, or you might even ask Bob Morrison where to get the stuff. I doubt he would be adverse to at least giving out that information.
http://www.crgrp.com/syntactics.shtml

Allan
Title: Re: what is a foam cored limb
Post by: amar911 on July 28, 2008, 10:59:00 AM
Mike,

I doubt Bob is tooled up to do that kind of work. It is not easy to do. If you have an ILF riser, Bob's ILF limbs will work on it, but otherwise I think you are out of luck.

Allan