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« on: October 10, 2016, 04:57:41 PM »
On a Bridgeport with steppers and a rapid of 2500mm/min, homing speed was set to 40%. I had a glass scale DRO on the mill at the time. I homed the machine and zeroed the DRO, moved off and homed and repeated I think about 100 times, only a couple of times did the DRO show other than zero. Now this was on a clapped out retrofitted Bridgeport and the chances are that the times it was out was more likely to be due to the slop in the axis.
The switch was a fully enclosed affair that had a rod poking out either side of an Alu case and the flag was attached tp the rod and the rod held central with springs either side of the flag. The switches were originally bought units from some place in the USA, I forget the name of the place but it changed hands and they stopped making them. Anyway the original optos in them gave up the ghost one by one and I just modified the housing and replaced them with the OPB916B.
The optos are cheap, about £6 or £7 here so even if they are not suitable for your job it is no big loss.
Hood