Do ceramic bearings effect touch probing?

Does anybody have experience using the tool setter or touch probe with a spindle that has ceramic bearings? Do they mess with the conductivity through the tool or do they work fine?

They kill conductivity. I had to switch back to attaching the magnet.

Agreed. My spindle with ceramic bearings requires using the magnet.

Ah, thanks, I suspected that might be the case.

How much does it bug you?

I’d buy a spindle with regular bearings. For hobby use the spindle will last a long time.


I’m considering ceramic because I expect to be cutting a fair amount of metal and other non wood. Also if there’s any noise advantage i dont mind squeezing every possible db out… But mainly its because although this will be my first hobby CNC, I’m coming off about 5 years running a lower end industrial 4x8 with a fairly serious spindle on it, and I’m a little worried that I’m more likely to get over aggressive with it than too timid :).

I like the G Pennys with the “bullet head”, they look cool :sunglasses:

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Hey Bunkstaff,

what prolongs the life of ball bearings in spindles the most is a spindle with sealing air. This reliably prevents anything from getting into the bearings and can delay bearing wear for years. You should also make sure that you have angular contact bearings in the spindle.

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True. A spindle of a quality level that would justify/include sealing air is likely gonna be beyond my means. But the bullet head g-penny looks to have a much less permeable business end, and it claims angular ceramic bearings(series 7 if that’s a real thing). It’s cheap enough that I won’t be in tears when I trash it, and if I don’t, then the extra 100 or so seems reasonable for some extended life.

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I went with the ceramic bearings as I think they can operate at much higher temperatures, I have the Air Cooled G Penny and the internal fan blows from the top down and I believe the bearings are sealed from the outside environment to some degree. My spindle even when running hard for several hours gets no hotter than 105 F using an infrared gun on the outside.
With regard to the tool setter, ceramic bearings have no effect on the functioning as it is a mechanical switch.

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Thanks for the info Pat. Yes I also expect I may have some very long cuts, that is indeed another reason I’m looking at ceramic.