Quote:
Originally Posted by caincteam2777
what did you use to raise and lower your arm?
|
It is a two-stage extension arm. The bottom frame of the first extending stage was attached to a loop of #25 chain run around a drive sprocket and an idler sprocket fixed to the base frame of the arm.
The chain was driven up and down by two Fisher-Price motor/Bosch drill gearbox combos mated into a single drive assembly at the bottom of the base frame of the arm. Reportedly, *math* indicated that this system could lift the weight of our robot plus at least one more....
The second extending stage (the one with the hook on it) was driven by a Globe motor (*sniff* RIP) and another #25 chain setup. Both stages operated independently, so the arm extended very quickly.
It should be obvious, but the first stage did the lifting once the second stage extended fully, and the arm tilt driven by the van door motor (*sniff* RIP) smacked the hook into place, preferably without first being driven in the wrong direction by our copilot, an aggravating trait we did not fully flog out of him until the 2004 Canadian Regional.
Magic was used to keep the robot hanging once we became 100% exasperated with the Bosch gearboxes' anti-backdrive pins.