cdb wrote: > The motor will be moving slowly - I'm not sure how slow, but it moves eggs so I would think hospital lift slow! > > > Opto Switch - Either with cam or just blocking a LEd A pcb drilling machine I used to repair used two opto sensors (at each end) of the horizontal travel. The flag attached to the drill head passed through the first opto gate at high speed and the resultant signal reduced the drive speed to a crawl so that the next sensor could stop the travel accurately and repeatably. A separate microswitch was used at the end stop to cut power to the drive if the sensor(s) failed. Geo -- http://www.piclist.com PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist