Looking for a machinable foam or flexible material.

[VTX]

Hi,

I have kind of an unusual project that I'm working on and I'm wondering if anyone knows of a good material that might meet my applications.

First, let me explain what the project is and what it is being used for. My company makes rifle scopes and we have dealers who want to be able to display the rifle scopes for their customers on wooden rifle stocks. The dealers want to be able to swap scopes out quickly.

So, I have an idea of a scope mount that is essentially a foam block that mounts to the top of the rifle stock. It has a "C" shaped channel in it, with the opening at the top. The opening of the "C" shaped channel is slightly smaller than the diameter of the scope tube. So, the rifle scope can be pressed into the channel and it will be held in place.

This should allow a customer to quickly swap scopes and try looking through them the way they would on a rifle stock.

The obvious choice would be some sort of injection molded rubber piece, but the mold tooling would probably be expensive for something like this. So, I was trying to think of a way I could just machine something on my CNC mill.

The material would have to have some flex and/or compression factor so that the scope can be pressed into place.

I already called and talked to the people that make the RenShape material and they said that it wouldn't work for this type of application.

Is there any kind of machinable foam out there that might work for this?

[animuL]

http://www.aircraftspruce.com/catalo.../lastafoam.php ???

[leo.dearden]

How about machining a positive (out of pretty much anything, say PP, or Aluminium, or even MDF), casting a mold round it in Silicone Rubber, and using that to cast soft PU foam.

Check out http://www.smooth-on.com/

try ecoflex 00-30 for the mold, and FlexFoam-iT! 25 for the product. There's a video example of casting a sword out of FlexFoam-iT! 25 somewhere on there. Or it might be on the cast magic product CD that they'll send for free.

HTH,

Leo

[ViperTX]

Guess, I'm missing something....I don't see how you'll attach a scope to a wooden stock using a cast urethane or foam piece. I personally would design a snap lock fixture....think of a snow ski binding....

[Titanium]

With the correct dimensions and a material like delrin or nylon which has some flex it could be done with much better results. I would concerned the foam would let loose of that
$ 1200 scope!

[tnik]

Guess, I'm missing something....I don't see how you'll attach a scope to a wooden stock using a cast urethane or foam piece. I personally would design a snap lock fixture....think of a snow ski binding....

I'd have to agree with ViperTX.. having some sort of quick snap locking feature would probably work alot better, and then at least you wouldn't take a chance of the scope 'popping' out of some rubber/foam/plastic.