Prototyping

I thought I had the dimensions right for this slow motion control but once assembled, it was obvious that the worm gear was. 23" above engagement with the spur gear.  Also putting the pillow blocks on screws in two different slots was less convenient for vernier positioning than I had hoped.  Solution: mount both pillow blocks on a .25" thick carrier plate and use the slot to position the pillow blocks side to side relative to the worm gear.   Using .25" thick plate both solves positioning problem while adding one slot to the base plate and solves the vertical positioning problem.

I briefly tried prototyping in acetal but acetal is so slippery that I cannot get a good grip on it with my mill vise.  Perhaps if I mounted spikes on the jaws.  CFC is rough enough that it clamps well