I was looking for a "mechanical" rather than electronic means of setting the Z axis height using something other than a piece of paper under the bit etc. V-bit tends to punch through paper.

I came up with using a business card taped to a block of wood like a diving board. It has give and doesn't damage the tip of the vbit. (Sorry if you have seen it before, I have not.) I slowed down the jog rate in Mach3 to about 20% and tapped the down key on the Z axus until the v-bit just visibly moved the card down ever so slightly. It is easy to see the card move. You can stand back and do it.

I marked the card so the bit hit the same spot each time. It is surprisingly accurate. I could get it within 0.02mm (0.000787402") to 0.05mm (0.001968504) of zero each time.

I just entered distance between the slightly lowered card and the top of the table using mach3. And then I added the nominal thickness of the material. So it was 24.16mm (0.9511811") from the lowered card to the table. The thickness of material is 6mm (1/4"). So I set the z height to 18.16. I ran a simulation in Mach3 first and it seemed ok.

Would you try this business card diving board idea and see what you think?

Setting the height to top of spoil board comes from here:

https://www.youtube.com/watch?v=Q-Q1...ature=youtu.be


Mike