very nice climber!
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Igus slides (cylinders) with the 1/2" polished aluminum shafts.
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That’s awesome. We prototyped something like that. The suction cup works well as long as there’s no damage (grooves) in the Hab surface HDPE. If there are, it doesn’t work very well at all.
Thanks! What type of suction cup did you use? When we prototyped our suction cup with scratched up HDPE, it seemed to work well so we decided to go for it.
These are the ones we ordered from Amazon.
This one, which I would guess is pretty close to yours. We tested it on HDPE leftover from last year’s platform though, which had some pretty good gouges - enough to worry us, but probably not as much a risk this year. Good luck!
What’s that piston doing at the end of your arm? Can you maintain suction after the match ends so the robot doesn’t crash down?
[quote=“AriMB, post:169, topic:343744, full:true”]
What’s that piston doing at the end of your arm? Can you maintain suction after the match ends so the robot doesn’t crash down?
[/quote] I believe the piston in the end of that arm pumps the built in hand vacuum pump on their cots suction cup that @echen01 linked above. If so, it can indeed maintain suction.
Is there any reason you didn’t use a motor with a cam to pump the suction cup rather than the pneumatic piston? Seems like a much more effective use of power than a large cylinder like that.
I’m asking because we went with this type of mechanism in 2003 and used a motor with a cam to great success.
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I like this one the most so far. Have you tested the suction cup on the textured side of an HDPE sheet, like the one that will be used on the field? And what is the vacuum mechanism that is being actuated by the cylinder? EDIT: should have read further, that’s answered.
@echen01 how are you guys deploying your climber arm and locking it in place so it doesn’t move during the climb? Also, are you guys planning on lifting any other robots with you?
The piston continuously pumps the suction cup to maintain suction for as long as possible. We can maintain the suction for about 4-5 minutes after the match ends, though we are working on a method to keep the robot from crashing down just in case.
We did think about using a cam but went for the cylinder for simplicity. We may or may not switch to a motor, but the air consumption isn’t a huge worry for us.
The climber arm is on a single stage lift with a constant force spring and some clever rope routing that keeps the arm from falling until it reaches its max height. A ratchet prevents the lift from backdriving. The rope is what keeps the climber arm in place and prevents the robot from tipping forwards.
We are thinking about adding forks and lifting at least one robot with us, though we are currently focusing on fixing up other areas of the bot.
Last year, our climbing mechanism was an elevator. We were afraid of sliding down if supporting another robot’s weight was too heavy so we made holes in the elevator and had locking pins operated by pneumatics. Turns out, we were strong enough that didn’t even need them. Not sure if you have to weight for this as each were about 5 pounds. Not sure what kind of metal the “pins” were but they had to be strong to be fail safes.
What gear ratios is everyone using for climbing. Asking for a friend…
0/7 bumpers didn’t stay above level 3.
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Highly depends on how you’re climbing, number/type of motors, length of your arm, diameter of your winch drum, pitch of your lead screw, etc. I suggest you check out my design calculator to help you find a combination of motors and gear ratio that will give you the specs you want for your specific case.
Team 5712 - Hemlock’s Gray Matter
Near successful climb during our Week 0 event
Team 2102’s first Hab climb:
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That absolutely made my jaw drop. what a crazy design
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