I purchased a tool height contact unit for my router and it requires either an alligator clip on the tool or ground through the bearings of the spindle. Since I want this to be an automatic operation at the beginning of each program I prefer the later. Anyone know of any problems running the 5v signal through the spindle bearings? is this the industry standard? thanks
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Mactec54
the 5V doesn't flow through the bearings - the bearings (or alligator clip) are always grounded - the tool setter is an open contact which floats at 5V by way of a weak pullup resistor - when the grounded spindle makes contact - the tool setter contact becomes grounded - during which time 5V flows through the pullup resistor - works reliably in my experience -
in some tools the bearings may be mounted in a plastic housing or rubber boot (insulated from ground) - in that case you could improvise some sort of reliable connection from the outer bearing case to ground (same effect as using a grounded alligator clip)
www.signtorch.com
I'm trying to do just this, but its not working.
It worked GREAT on my old Bosch Colt. Now I want to implement it on my new 600w spindle.
I've got the parts made up, and thinking it would be a straight plug and play, it's not.
Seems like it is electrically interfering (shorting out) with the other electronics.
I have no resister in line, and honestly, not sure of the polarity (Going to double check tonight)
But if I can get this working. its a supper set up!
I have some pictures, but can't seem to get them uploaded.
I'll try uploading them again later(might be a work computer thing)
My Build: http://www.cnczone.com/forums/diy-cnc_router_table_machines/113711-my_build_-_many_thanks.html