Z Zero 0.9mm end mill

[paul_z]

I have some 0.9mm end mills that I have tested and they cut extremely crisp holes and lines. My question is how do I Z Zero such a fragile bit?

[bleeth]

You might try going into the z zero file and changing the down speed and then saving it as a different custom file but the safest way is to do it by keypad manually. a piece of paper between your surface and the bit used like a feeler guage is helpful.

[billp]

Paul,
Years ago I did this with a similar sized bit, and I just wired in a piece of copper circuit board to the z zero wire. This way I knew the copper surface was "soft" enough for the small bit tip to contact without significant smushing...

[dana_swift]

I have some very tiny end mills, 0.020. The way I zero them is change the second touch speed on the ZZero routine to as slow as I can get it. Then I lift the zzero plate above the surface about a tenth of an inch, so it gets its first touch "near" zero, then I lower the plate to the surface for the second touch.

Its the first touch when the Z is moving fast that is the problem and can break such small bits. The second touch going slow is not a problem.

Your bits are about 0.035 so that should work.

[curtiss]

I use the same procedure with small bits as Dana... One thing I learned a week or so back, is that when you rack up the z-plate after only the first touch,

the "second touch" goes very poorly....

[dana_swift]

LOL.. Curtis I can see that in my mind. Its good for bit sales tho..

D

[paul_z]

Excellent ideas all! Thanks for the help.

Paul Z