The Crawler

I spent a little more time working on The Crawler this weekend.  I managed, despite my effort at precision, to get the two shafts out of parallel.  The primary driven shaft is pretty straight, but the secondary shaft was out of parallel.  This means I needed to move one of the bearing mounting points to bring the secondary shaft into parallel with the primary shaft.  To do this I cut one of the frame rails, slotted the mounting holes in the top sheet metal, and then shortened the frame rail by 0.050 inches.  The modification is barely noticeable.

Also I found a battery holder that I can tuck under the frame rail that was modified.  This gets the battery off the top of The Crawler so there is more space for the microcontroller board, and test equipment.  Another thing that needed to be modified was the motor shaft.  It has a notch in the 1/4" output shaft, and the Pulley is round in its bore.  So a made a 0.060 inch thick piece from a 1/4" shaft to fill in the notch in the motor drive shaft.  This holds the pulley more squarely on the motor drive shaft, and helps alleviate periodic strain on the drive system.  The pulley is still kind of eccentric, and causes periodic strain on the drive system.  Its something I need to fix next.