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Unread 30-01-2017, 21:32
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Re: How many seconds to climb the rope?

Quote:
Originally Posted by bobbysq View Post
Here's a test with a 100:1 VP and a 775pro on our 2016 robot (nearly at the weight limit)

https://www.youtube.com/watch?v=VyNp-fGKJDk
Thanks for posting test footage!

What is the diameter of that spool that the strap is winding around? Also it sounds like you have some kind of speed control on the motor, have you tried going 100% throttle as it climbs up?

With a 100:1 reduction on a 775 and a full weight robot, you'll start to draw more than 40 amps when you're spool reaches about 2.5" in diameter (which is kind of the limiting factor with the breakers, but they won't pop immediately if you go over 40 amps). With that size of spool it should take just over 2 seconds to span the distance from the top of the robot to the davit.

As you make the spool smaller in diameter, the motor will draw less current (you're electronics system will be happier) but your climb will be slower.

Be careful not to let the magic smoke out of the motor!
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Unread 31-01-2017, 11:19
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Re: How many seconds to climb the rope?

Quote:
Originally Posted by s_forbes View Post
What is the diameter of that spool that the strap is winding around? Also it sounds like you have some kind of speed control on the motor, have you tried going 100% throttle as it climbs up?

With a 100:1 reduction on a 775 and a full weight robot, you'll start to draw more than 40 amps when you're spool reaches about 2.5" in diameter (which is kind of the limiting factor with the breakers, but they won't pop immediately if you go over 40 amps). With that size of spool it should take just over 2 seconds to span the distance from the top of the robot to the davit.
I believe we weren't gunning it, but we were going maybe 80%-90% speed. The tube was a PVC pipe around 1.5" in diameter. Our test rig actually used an ATC fuse box, so it only had a 30A breaker and we were surprisingly able to stall it for a little while. The full robot will probably use a 40 amp breaker though.
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Unread 31-01-2017, 11:21
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Re: How many seconds to climb the rope?

Time to pony up and make it official. Go vote!
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