Shapeoko Pro XXL, HDZ, bitrunner, bitfinder and bitsetter.
I have stops on spoilboard and saved it’s x-y-z zero in quick actions (user)
I run the following procedures to setup for carve.
Connect to cutter
initialize machine
on run menu go to quick actions, user, and run macro where I saved home posisition
on jog menu go to rapid position, rapid to current z, pop up says tool not measured would you like to measure it. I click yes and it takes a trip to the bitsetter.
when I go to run menu it says z is not set ,set or continue, I continue.
At this point I have the x-y-z set and ready to carve.
This takes about 6 or 7 clicks and less than 10 seconds.
So far I have had no issues with this procedure, Does anyone see a future problem I haven’t found yet.
I’ve found initialization with proximity sensors to be, in extreme conditions, as much as 0.010" off.
Usually within 0.003". So for higher tolerance work, I don’t trust it. Or the bitsetter. I’ve had a few cases where consecutive tools were cutting at different depths.
If you’re going to cut away your Z index point on the stock, touch off to the spoilboard & make a note of the Z height. You can always use that as a reference.
My general experience is whenever the CNC is turned off I have to reset my zero. I do trust the bit zero, so much so that if I lose power and have to start over, I’ll zero the project with BitZero and continue on (unless I’m tiling… that’s a completely different plan).
I’m not sure I follow how this works how its written but I could be missing it… Because step 4 isn’t setting Z0, its just adjusting wherever its set for the current tool. Then 5 says you skip setting Z0 by choosing Continue. Maybe I should back up…
When I first connect and initialize, the value of Z0 is unpredictable. My experience with CM and a 2025 Shapeoko 5 is this. When I power on for the day and initialize, XY0 is remembered, to within .001" usually, of the previous session. Z0 is anybody’s guess. Sometimes it’s exactly where the previous session ended. Sometimes its at the top of Z travel, or some random place. I just don’t know.
So I would never try to run a built in or saved command to move to Z until I have manually set it by jogging to it. I change Z0 a lot. Most of my projects involve making 2 parts which are then glued together into one taller part. Then come back the next day to machine the taller part.
Because I’m paranoid haha after I set Z, THEN I do Rapid to current Z at a clear place on the table outside the material. I keep a stack of cutoffs for each size material I use. These act as feeler gauge I can slide under the bit to confirm Z0 is in the correct place.
GRBL remembers the Z zero as well. But it’s the position of the Z axis / Spindle, not necessarily the tool, as they all have different lengths.
But if you have the same tool in the spindle at the same length, i.e. you haven’t removed it since…
then your Z should be right where you left it. (within tolerance)
Don’t get me wrong, I ALWAYS check it as well as the XY zeroes.
Tod1d, I didn’t know GRBL saved the spindle location. Thanks
4wm. The way I explain it is to put the cutter at your desired x, y and z location. Go to Run, Quick Actions, User. Save the location with a name. That will save the x,y and z zero. When you run that macro it tells the machine where the x,y zero is but the axis does not move. When you go to rapid position, Rapid to current z and say yes to do you want to measure tool, the trip to the bitsetter sets the z. I think this is as safe and quick as any method. You can change tool before going to rapid z.