pic: 2791's Shifting Winch

Not sure HOW clever this is, but it’s a cool use of COTS parts in my book and the combination of me and the other team members that thought of how to use various parts of this design are proud of it.

The whole assembly is 100% COTS except for the metal holding the ratchet in place. The CIM drives from here through an AM Planetary and AM Toughbox Nano to the winch, made of two AM Hubs put together. On the end of the winch is a socket wrench, the end cut off and welded onto some metal. A servo is attached which allows us to activate and deactivate the ratchet; since our arm is a spring release, this lets us control the unfolding motion and the folding motion with the same motor.

Using JVN’s spreadsheet, I’ve speced the robot to about a 3 to 4 second hang.

I love how many teams are using Mastercraft (or similar) GearWrenches as a ratcheting system this year for their winches.


we thought of using a gear wrench because it would have been easy to implement especially with our love of 1/2 hex. In the end we just decided to rely on the Dewalt Roll back pins.

Well, it’s cheaper than the one you can find on McMaster, and one of the mentors used to sell them so I guess he had a few around :smiley:

you could always use a craftsman and take it back after the season :smiley:

Actually it is a Craftsman, the Evolv Series. Still lifetime warranty, the ratchets work the same from both series, but the Evolv closes with screws instead of a snap ring. We did need to make a custom steel output shaft yesterday. I had the ratchet backwards and cim sheered the AM Al hex shaft in half! Needless to say I almost had a heart attach. But after we fixed it I thought “that is a lot of torque” so I guess it is doing its job.

Just being picky - but the proper expression would be “that is a lot of torque”.

Good point. Thanks