Z axis not holding...slipping:(


Hole Test 1A.nc (29.8 KB)

1 Like

Wait…which version of CM do you have ? Just checked on CM 511 and it does not have a pop-up notification unless you activate the BitSetter option.

I’m using CM 513…

ok my bad, it does have the tool pop-up (later/ after run).
G-code looks fine

I ran your nc file on my machine and got the correct behavior: it first goes up to the top of the Z axis minus 5 mm, due to the following line:


then M05 (spindle stop / irrelevant here)

then comes the M6T102 which is the tool change command that brings the tool confirmation pop-up.

And then it goes down, to start the actual cutting job:

it will first go down to retract height (5mm above Z0):


and then proceeds to cut the first pass at 0.76mm depth (0.03", as specified)


So…what exactly is not happening correctly ? Your video stops when the cutting would have begun, if you had turned on the router and let it proceed, or am I missing something ?

Sorry it took me a while to respond, I don’t use CM so often anymore and I had completely forgotten about that behavior to raise the Z to the top minus 5mm at the beginning, and wanted to run the file myself to double-check.

oh but this reminds me of another comment I initially had while watching your video:
assuming your video starts with the endmill touching the stock surface (Z0), you can see that there is very little Z travel left to go downwards: maybe what happens is that the cut begins normally, but after a while, it reaches a cutting depth where the HDZ bottoms out mechanically, it cannot plunge any further, and then you lose motor steps, which would be why when you check Z0 AFTER the job is completed, it’s off.

Since you don’t seem to have a wasteboard on top of your baseboard, that is a possible explanation (stock is “too low” compared to available Z travel)


No worries Julien, its a crazy time! Sorry for my delay, needed to give my brain a rest:)

Yes, I just stopped the program as I thought thats all u needed to see.

DUDE, you are BRILLIANT! Went back and checked, you were right, there wasn’t enough travel on HDZ! Thanks explains it. It looked like it had enough, it was short by about .0300", doh!

Cannot thank you enough Julien! I owe you a beer, ok a few:)


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