How do you ZZero a diamond coated bit?

[paul_z]

Being the cautious operator, I tried to use an ohmmeter to make sure the coating is conductive before using the ZZero plate. Apparently the coating is a very poor conductor.

So how do you ZZero a diamond coated bit?

Paul Z

[steve_g]

With a feeler gauge and the "fixed" distance feature of SB3?

I have some rubber that is more conductive the more pressure is applied... I wonder if it would be consistent enough.

Steve.

[Brady Watson]

You'll have to set it manually. You can use the material or the plate as your reference. If using the plate (to protect the material), use the keyboard to get the bit about .25" above the material. Slide the plate in. In keyboard mode, press the D key or click on the Fixed button. Enter a value of .01, then keep hitting the Page Down key until the bit just touches the plate. If the bit is 1/16 or smaller, you might want to change the Fixed distance to .005 just to reduce the chance of impacting the tip to the plate.

Once the bit is just touching the plate, use the VA command to set the Z value to .121 (or whatever you measured your plate thickness to actually be) and you're done.

Otherwise....you can just eyeball the tip of the tool touching the material and ZZ or slide a piece of paper in between (mic the paper...) and bring it down .005 at a time until you cannot slide the paper out. Then ZZ or VA paper thickness.

What method you choose depends on the accuracy you need to hold...Most times just eyeballing it is sufficient.

-B

[gene]

could you put the bit in the collet , slide the plate under the bit , lower it until it touches and then tighten it up. would that be any easier?

[kenz]

Wrap it in foil.

[paul_z]

Ken's suggestion about foil gives me an idea. I'll make a brass sleeve with a bottom (like a cup). The sleeve will be pulled up on the bit with a strong rubber band. The ZZero clip will be clipped onto the sleeve and ZZero will operate as normal. Knowing the thickness of the bottom of the sleeve, I can compensate for the sleeve.
I’ll probably add a “sleeve ZZero” routine so the compensation will be automatic.
Thanks Ken!
Paul Z