touch probe connectivity with ceramic bearings

**voyager1972** · 2 Weeks Ago

having mounted a spindle which has cermaic bearings the touch probe no longer has connectivity , is there a workaround for this ?

**JohnHaine** · 2 Weeks Ago

What form does the probe take?

**voyager1972** · 2 Weeks Ago

form ?

at the minute i just have a simple probe one wire to the probe input ,another wire grounded on the frame .

**JohnHaine** · 2 Weeks Ago

So I think you mean the probe is a rod of a known diameter which used to be connected to ground through the bearings but is now isolated because the balls are ceramic. So you need to clip a ground connection to it with a "croc clip" or the like.

**voyager1972** · 2 Weeks Ago

I had thought about the Croc clip , is this the only solution to the problem , how do the big machine manufacture get around this

**pippin88** · 2 Weeks Ago

The big manufacturers don't use touch probes that involve a circuit through the spindle / machine frame.

They use infra-red or wireless communication often. Probe is battery powered.

**JohnHaine** · 2 Weeks Ago

Most of the cheaper "professional" touch probes are based on the original Renishaw design (the basis of their present success), which essentially has a normally-closed switch that opens when the probe stylus touches anything causing a microscopic movement. The opening of the circuit can be sensed in several ways, some of which involve a ground connection. You can buy quite low-cost probes now based on the same principle. Generally use a wired connection relying on power from the machine.

Renishaw have much more advanced systems now often using wireless or optical and the probes can be mixed with tools in an ATC carousel, and also probe whilst rotating. Correspondingly MUCH more expensive!