Making a Height Gauge PT2

This spindle is an NT30, and the R-8, tool holder looks a little different.  Don't worry, this will work the same way in an R8 collet, or whatever you have.

You are using your CNC as a height gauge.

If you have a CNC Mill get close to the surface, then loosen the quill lock and press the tool against the surface, and re-lock it.

To be exact, what we care about is the fact that the bottom edge of the tool is at 0.0000

Drive down until you find a number you like.  The number is arbitrary, just find a place that you can repeat.

You'll notice we added a spring under the plunger, the little spring inside the indicator didn't press very hard with the aluminum plug on the top.  We just added the spring on..

We stopped going down when everything points straight up.

Notice the little black dots on the face.

Ours says Z 5.6702" from the table.

This is YOUR OFFSET.  REMEMBER THIS NUMBER.

We just dropped the 0.0002 off the end.  This way we just need to remember 567 and we're good to go.

You are now good to go, You can begin machining, or touch off the next tool for the run.

Be sure to save the tool table when your done "touching-off" tools

For those who do get it:

It's possible to use a similar approach to get the Z offsets for fixtures as well, plus it's quick and accurate.

For those who don't get it:

Look at it this way, a few pictures up you see an end mill pressing down on the gauge.  My hands on the dial are at their known point (Big hand at 0, little hand straight up).  So I now know that the bottom of the end mill is EXACTLY 5.670" above the surface (top of table).

The steps following that tell the controller that the tool 14 (my 1/2" 3 flute) is EXACTLY 5.670" above the table.

Since the controller knows where 5.670" is, it now also knows where 0" - 20" are.

So I can say "Go to Z 0""and that end mill will just touch the table, or I can say "Go to Z 1"" and it will go to exactly 1" above the table.