kproche: (Jungleboy Transparent)
kproche ([personal profile] kproche) wrote2013-04-17 10:48 am

Eppur si muove

The one last thing I'd hoped to add to ThinBot for Robogames this year was motion, to swing the glass in and out from under the spout, making it easier to place a glass and pick up the finished drink.

I'm happy to report I got it working!



These parts were fun to make. There's a trick in the counterweight -- the groove fakes out the eye so you can't tell if I matched the outer diameter exactly on the top and bottom halves.

Brass Counterweight for arm, bottom
Brass Counterweight for Arm, top/side view

The complete arm assembly, screwed onto the servomotor "horn":
Assembled glass rest arm and counterweight

The servomotor, with mounting hardware. The scrap of paper is to keep a set of shim washers in place; the washers transfer the weight of the arm to the case of the motor, so there is no axial load on the mechanism. The counterweight eliminates any side load on the shaft.The whole arm/glass during operation could weigh nearly two pounds!

Servomotor with mounting brackets

Finally, here is (bad) video of a motion test:






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