horizontal bar clamping device

[cosmicexplorer]

For pyramid climbing: I'm considering a way to rotate our robot upwards off the ground by clamping onto the horizontal bar and swinging our robot body up, like this poorly drawn diagram.

http://i.imgur.com/D1Hvs.png

Two questions:
1) What kind of clamp would be able to stay in place without slipping? Is it COTS or can we build it ourselves?
2) Is there a way we could make the clamp not require motorization (because motors are heavy and draw power)? For the motor that would be rotating our robot body upwards, would a window motor work on its own? Would two? Or would we have to have some intense gearing? We expect our robot will be around 100 pounds at the very least, weight is always an issue with our team.

[Kevin Sevcik]

Window motors would be hopeless unless you want to spend all day climbing the pyramid. You want to use a CIM with a really high gear ratio.

[DonRotolo]

Preventing the clamp from rotating on the horizontal bar would be very difficult in my opinion. Especially without damaging the finish of the bar.

Here is a different idea: what if your clamp were to clamp onto the bar and the robot were to spin sideways, in the plane of the pyramid's face? If the clamp were several inches wide and had a soft grippy foam surface, it might not spin around The axis but lift the robot into the air, kind of like what team 33 did in 2010 breakaway.

[Kevin Selavko]

Also you will have to be able to remove the clamp unpowered.

[Justin Montois]

Think monkey wrench

[cosmicexplorer]

Preventing the clamp from rotating on the horizontal bar would be very difficult in my opinion. Especially without damaging the finish of the bar.

Here is a different idea: what if your clamp were to clamp onto the bar and the robot were to spin sideways, in the plane of the pyramid's face? If the clamp were several inches wide and had a soft grippy foam surface, it might not spin around The axis but lift the robot into the air, kind of like what team 33 did in 2010 breakaway.

At first when reading that I thought you meant going up the diagonal, but what you propose is actually really interesting. It also means we could do it with just four or so motors. Making the gripping claws wider would mean we'd be relying on the grippiness of our claw, too. If our robot is short enough, we might be able to swing up and grasp onto the third horizontal bar with two clamps. We'd have to be able to dislodge it unpowered (thanks Kevin), but there's probably a way to get around that.

Hm. Definitely something to prototype. Thanks!

[JPC]

Preventing the clamp from rotating on the horizontal bar would be very difficult in my opinion. Especially without damaging the finish of the bar.

Here is a different idea: what if your clamp were to clamp onto the bar and the robot were to spin sideways, in the plane of the pyramid's face? If the clamp were several inches wide and had a soft grippy foam surface, it might not spin around The axis but lift the robot into the air, kind of like what team 33 did in 2010 breakaway.

We did some concept packaging of this idea. We struggled with the robot package running into the pyramid and getting the second clamp on the second bar before moving on to other ideas.... Just want to help you avoid or design around the issues we saw if you go this way.:)

[Ninja_Bait]

Grabbing a corner gusset may be better than grabbing a rung. Also, think bear trap for your clamps if you don't want to use motors.