[Lab] 3.6k pot (Darcy Whyte)

[Adrian Jones]

Darcy,
A simple LED/photo resistor set-up, interrupted by one end of the toothed
cable, may be sufficient for setting an start point so that you know where
the spiders start. Then count the number of steps necessary for the stepper
motor to move the spider to the end point et voila. I used this simple
set-up for the pair of escalators I built for my partner's artwork
installation and it works well.
A geared stepper motor works really well when you want really slow
movement... See
http://www.ebay.ca/itm/221347325924?ssPageName=STRK:MEWNX:IT&_trksid=p3984.m
1497.l2649 Cheap and easy.


Many thanks, 

.... Adrian