$102 - Z-Steps/mm Default

Can anyone confirm whether a $102=188.976 value is the default value for this parameter? And if a user changes this value after a Z-axis calibration process, will it get reset to a default value if you are forced to perform a Machine Setup process. A search through the forum for $102, yielded a lot of results where the $102 value is reported as being 188.976 (so I’m thinking that is the default), as well as a lot of complaints about Easel resetting this parameter back to this value.
For some reason, I have been forced to go through the Machine Setup process twice in the last five weeks, and I now realize I should have done a better job of recording these values (as well as $100 and $101).
I think I have finally come up with a good Z-axis calibration routine, and I’m looking for confirmation of my starting point.

Default microstep is 2
Stepper is a standard 1.8deg per step, or 200 steps per rev
The 3/8-12 leadscrew has 12 threads per inch = .08333 in/revolution = 2.11667 mm/rev

2*200 steps/rev / 2.11667 mm/rev = 188.976 steps/mm


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Thanks, Neil!!!

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@RobertNichols I would suggest keeping a log. Anytime you make a change record the original and the new setting.

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I store a screenshot of my current GRBL settings locally and in the cloud.
IIRC I think PhilJohnson once descirbed a way to “auto import” via UGS as a macro?

Thanks guys!!! I have started a log of my Grbl settings, and keep a copy on both the laptop I use to run my machine, as well as my home server for backup purposes.
Any insight as to whether a Machine Setup resets the value of $100, $101 & $102? I suppose I could revise these values to something arbitrary, do a Machine Setup, and check the results. If they get reset I can then “use my log” to revise them back to the correct values.

@RobertNichols. I have heard that as well. When I added my new z axis I had to change the settings. I have tested this numerous times and no, it has not defaulted back to the original setting nor should it.

I am pretty sure if you run the Machine Setup it will reset all your setting back to the original settings. So be sure you have them copied. There is one way to find out.

Good to know!!! I watched your video on your Z-axis upgrade and may do the same. Besides the gain in height capacity, did you notice any performance changes. When I was researching $102, I saw a comment about increased speed, but I can’t find it this morning.
Thanks for your help, Phillip

Have you resolved this issue? If so, can you help me understand how to fix it?