http://www.thingiverse.com/thing:2414

http://www.thingiverse.com/thing:2433

http://www.thingiverse.com/thing:2415

There's lots of ways to make grippers and the material can vary from abs plastic , wood or even sheet metal. It's going to come down to what your comfortable working with as far as materials. Dont cheap out. You will probably spend 100 dollars on a well made gripper including the servos , wire , and materials used. If you are ok with 3d printing you can print one and add servos but it will still be a similar cost. The little things seem to add up.

Well, I found plans for an arm made of foam board(re-enforced) and I'm planning on doing a similar build to prannav's foam omnibot. So I was looking for an idea for the gripper so that the robot could pick up light-weight things. I didn't want to go and buy the 60 dollar grippers from ebay and the idea vhs896 gave me is basically the grippers on ebay but made of low cost durable material.

The most I have spent on any of my robots is well. Just on the ez-b and servos. The rest I like to use junk or free stuff. And I'm poor... lol

If you want it to work and look half decent I would take @aameralis up on his offer to knock up something for you and have it 3D printed. Or use it as a subject to get in to 3d cad and designing stuff for 3d printing.

To be honest, a lot (or probably all to be brutally honest) of the claw designs I've seen online are complete junk and not worth bothering with. If it needs to actually pick up something I don't think any of those linked to would do a satisfactory job.

Can we see some of the claws that you have made and tested? Like the ones that you say are junk? LoL after all. Its just bran storming here.

SMRT LoL smrt .... I have a crayon in my bran? LoL j/k

I made this gripper at a local fablab. Here's my result:

www.fablabamersfoort.nl/en/fabpublication/servo-claw

It only uses one servo and it's surprisingly effective at picking up objects.