Horseshoe Mount

               pillow block72.jpg (25762 bytes)   Homemade  Pillow Block and Motor Mount - declination axis    101-0198_IMG72.JPG (27152 bytes)

The pillow block has 1/4" x 3/4" bearings.  I drilled a 3/4" dia hole 1/4" deep on each face and a 5/16 hole through the block.  The trick is to get the 3/4" od bearings aligned so that the shaft is exactly perpendicular to the face of the motor mount.  I did this by adding a 1/4" ply face to the pillow block with the 3/4" hole drilled in it.  Then with the bearings and shaft installed and aligned, glue the 1/4" ply in place.


                                         gearbox172.jpg (82639 bytes)    Gearbox for RA axis    gearbox272.jpg (91635 bytes)


openfacegearbox72a.JPG (65559 bytes)  The front of the gearbox is removed for this photo.  The stepper turns a 3/8" shaft, which drives a 1/2" x 10" diameter steel wheel.  This wheel in turn has a 3/4" shaft which turns the 42" double banded horseshoe.


RA_encoder.jpg (74653 bytes)   Placement of the optical encoder on the RA axis.  8192 count encoder with 8x gear.  65536 ticks per revolution.