[lgr]

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

[mactec54]

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

It most likely won't be very reliable, it is best to add a Brush, to run on the spindle up at the top is the best place, this is also a good idea to get a longer life from your Bearings, something like this can be quite small

[SignTorch]

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)

[Mogal]

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)