Missed steps for sure you need to tune your Axes or turn down velocity.

The STEPCRAFT Grease will cause the axes to bind up in the cold.

progressively drops?

Check your main board has power? and check you are using the correct profile?

Clean of the STEPCRAFT grease and use light spray oil... 3in1 or WD... this will make a big difference to top end performance reapply regularly.

You are running UCCNC on the default profile. you need to run the STEPCRAFT specific UCCNC profile.

Yes - if the location is cold the grease can cause this. Best use light oil little and often

Check for duplicate vectors...

Remember also that the proxxon can only "work for 15mins before having to cool" any longer use and you've voided warranty

Remember smaller cutters will also deflect under load. we see commercial machines with better than 10 micron accuracy show weird circles if you dri...

There should be no reason to see any accuracy issues related to buffer or software related communication when using the UCCNC most likely its backl...

I think too much for a STEPCRAFT. you would need big cutters and big depth... STEPCRAFT Q better option

Correct setup wlll achieve good results. We have many clients doing this

Shallow pass depths... 0.1-0.2mm per pass and work from there

IF rollers are loosening then use loctite threadlocker on them have not come across this before. If you use loctite then super careful if you ever ...