Team 172 Prototyping
 

While our final design is still being worked out in the computers, we've assembled a simple gripper onto our 2004 Tetra bot, showing how truly simple a robot can be and still function in this game. If it hadn't been assembled two years ago, the robot you see in these pictures would be quite capable of competing (minus a few small technical updates in the rules and whatnot) and it would be able to score on all goals.

...Now if only our engineers and students in the back rooms could get that into their heads and design something this simple! :)




Essentially, it's a single pneumatically actuated solid boom on an A-Frame, with a three pronged pneumatic gripper made of aluminum tube from around the shop, and a little bit of surgical tubing (so that we don't poke any more holes in the tubes than we need to...). All the upper mechanisms are pneumatic and rather lightweight, and it only really has two moving parts for the whole gripper mechanism. Simple and effective. :cool:

Re: Team 172 Prototyping
 

can you safely control the height of your arm or does it jerk up and down as you actuate it?

and...How do you control the height?

Re: Team 172 Prototyping
 

The arm moves quite smoothly with the rings as a load. We have flow control valves on the pneumatics at both ends, so the arm moves at a rather constant speed up and down. (although, it admittedly is a little more jerky on start/stop then I would like. It's bearable)

As for height, it's currently just by eye. For the Tetra competition, we did mount magnetic sensors on the cylinder, that would act similar to limit switches when the piston reached points within the pneumatic cylinder, but they were never wired for that competition. We could do similar for this years after a little bit of tweaking to figure out the heights of the rack relative to the arm.

Most likely, though, our lift arm will be powered by an electric gearing rather than pneumatics, although in a very similar configuration.

Re: Team 172 Prototyping
 

This looks great as a concept, I love simple bots! When teams focus on designing things really well instead of arguing concept the results are always fantastic.

Maybe you could include something to rotate the wrist and change orientation of the tube for scoring?

also, it looks like this bot probably falls well below regulation weight... am I wrong? maybe you could devise a way to eliminate any CG issues and raise stability.

Re: Team 172 Prototyping
 

Nice gripper mechanism! Simple, yet very effective.

But for your arm, watch out for <R12>...you might be pushing it from what the picture shows.

Re: Team 172 Prototyping
 

Nice and simle.

Re: Team 172 Prototyping
 

We do plan on adding a simple wrist mechanism on the final design, with something close to 120 degrees of rotation around a pivot.

As for weight, the base robot still is using the old gearboxes, 4 CIM motors, and a good amount of 8020, so it is up there in weight (~110 lbs), but with the new drive train this year, and some strategic use of materials, a robot could be re engineered around the same basic design and easily save 20 lbs.

And, thanks for the heads up technoL. This robot would be pushing it in regards to <R12>, and we'll definitely look into that before we decide on something final.

Re: Team 172 Prototyping
 

Reminds us of our Team 987's robot in 05...are you sure the two foot piston is legal this time around? We didn't see your piston on the order form for this year's build.

Re: Team 172 Prototyping
 

I do not think that the piston is legal this year, that's why we're turning towards an electric powered chain/sprocket for the new build.

Re: Team 172 Prototyping
 

The 2' piston is legal, it just has to be 2" in diameter (or 1.5" according to the Bimba site for some reason).