Cheap Motors; cheap for a reason

I love a good deal. But more than the deal is the hunt, garage sales are the best for finding that goldmine. This story takes us to ebay…

There was a pair of WheelChair motors, with wheels, crazy cheap. When they arrived they both worked, but one was much faster than the other.  It wasn’t untill they were mounted up to the frame of the robot that curiosity got the best of me and I  had to find out why one motor was so “clunky”.

Gotta love Cnc, from print to part in moments.

I pulled the motor bolts out, removed the brushes, and the case and endbell came off as one unit.   So did 2 of the magnets…

Just Busted loose, not broken or even chipped. The magnets had clung to the armature, when the motor  reversed direction the magnets would rotate with the laminations till it hit the bolt that runs the length of the motor can. The “Clunk, clunk” noise

You can see the groves worn into the magnet from rubbing on the steel laminations. Tough magnets indeed.

One i’ve prepaired previously. Glued that magnet in yesterday. Couldn’t imagine trying to keep 2 glue soaked self repelling objects in place…

A clamp should hold this well enough till the glue sets up.

Hacking Harbor Freight

I love and Hate Harbor Freight tools. Everything is “junk”, but its all cheap, and some select items are a good value for money.  In the game of combat robotics, where the total operational life of a robot can be as short as 6 minutes, it makes sense to shop for parts at the temple of HarBot Freight.

$15 buys you a somewhat OK propane torch handle, with valve and Piezoelectric starter.  It stayed whole for about 20 minutes. End Result, a nice compact propane bottle fitting and shut off valve, or so we thought…