The inventor pics look exactly like the real pics, except for the hands and the drill in the real pic of course.
I think that’s a very nicely made design. Seems like it’s pretty sturdy the way it’s created. Based on it’s small size, I’m going to guess that you are just planning on grabbing at the top of the tetra.
It really is great when drawings go perfectly to “real life” like that.
It’s hard to tell from the pics, is the piece that holds the gripper the cylinder itself? Seems like it could be bad to hang the tetras off the cylinder.
Are you grabbing them from the top apex or by a side bar? Just curious.
bent cylionder= BAD news
I agree, and it looks like the support IS in fact the cylinder itself. That could even be classified as a safety hazard. If the cylinder takes a blow from a defensive robot, or an obstacle like a steel bar, there could be an explosion. They could wrap something soft like a spongy kind-of material around it and that would soften any accidental collisions. Just don’t get too aggressive with it or anything! 
Those cylinders have kind of thin walls. If the assumption being made here is correct… be careful. But I do like the design. Seems light and strong. And the claw looks exactly like the inventor drawing… We dont even make plans, not to mention inventor drawings that we could follow as exactly as you did. Great Job!
60 psi isn’t enough for a real explosion*, but I can recall at least one such design failing after a few rough matches–team 22 used a cylinder as a support last year, and had it come apart on them. Granted, they put a lot more load on it by design–but in a collision, you’re certainly asking for damage.
What about putting a PVC tube or an aluminum extrusion around the cylinder?
*Provided we’re talking about a clean fracture, and the relatively large and heavy gripper coming off–if this were something that could produce shrapnel (which it isn’t), 60 psi would be much more hazardous.
putting it in pvc might make it a bit stronger if not it will be a barrier IF the cylinder tries to burst. but if you were to put aluminum extrusion around, i think itll defeat the purpose of the lightweightness of a non suported thing.
i had thought about making a gripper like this and then abandoned it in fear of bending the piston rod.
are you able to open the claw by hand? I can’t find the rule, but i believe you must be able to remove a tetra the robot is holding at the end of the game without powering it up?
Thank you all for the safety tips, we are going to grab the tetra by de top, we can open it by hand if necessary.
The claw will be always pointing to the ground because it is suspended by an axis in the middle of the cylinder PICTURE
i meant i was worried about it in that the refs wont know how to open it… see
http://www.chiefdelphi.com/forums/showthread.php?threadid=34392
i like they claw idea. it looks like itll be very effective. nice job!
Thank you for the compliments! It was hard to do it.