Setting zero on Z axis

[fourwheeler]

What are you guys using to set zero on the Z-Axis?

[cteufert]

I have been using a corner of an index card under the cutter. I jog down until it just grabs then I know the surface is 0.010" below... the card is 0.008" and the additional 0.002" is the gap that lets the card just move without tearing. (Verified by measuring a step machined in to a block.) I like using the index card because it gives a bit of a cushion should you over run, preventing the material from getting a dimple. It is also nice that a nice round number, 0.010" is the offset.

Since I installed the touch probe yesterday I will be moving towards using it and the known heights of each tool. This works for me since my tooling is being installed in TTS holders so they always go back in at the same height.

[UUU]

I use a 6mm roller - jog close to the surface, then jog away until the roller will pass under the tool. Then set Z at +6. I prefer this method to the card or shim method as the jogging away is safe from overrun.

[kvom]

I have one of the electrical contact boxes that light up when the tool touches.

If the box doesn't fit for some reason, I use a 123 block or a gauge block, jogging up .001 until it just slips under the tool.

[John Gamble]

Might want to check out Edge Technology Products for their 4 In Touch Off Tool. (See attached Picture).

While its advertized for Z touch off only, I use it exclusively for X,Y & Z touchoff.

For my money its:
1. Quick
2. Safe
3. Accurate

Gave up using paper , feeler gauges etc.

John