I have at last measured and set up the backlash compensation on my SC420/2.
I used my DIY digitising probe with a 2mm ruby ball and a micrometer set to 3mm to allow me to move each axis by exactly 1mm. The DRO on the UCCNC "Run" screen indicates the amount the stepper had to move to achieve the 1mm axis movement - the excess over 1mm being the backlash correction required.
When taking these measurements, disable backlash temporarily to get a true figure, enter this in the appropriate parameter box, re-enable backlash, use the new settings and double check before saving the profile
In my case the X axis required 0.21mm and the Y axis 0.80mm, and afterwards the DRO read 1mm +- .005mm on both axes. The DRO was set to zero at one extreme to more easily see the required value
Here is the measurement setup for the X axis.
Hope this is useful
Peter
SC 420/2, Industrial VFD spindle from StoneyCNC
UC100 + UCCNC
Cut2D, Autosketch10, Draftsight, Eagle 9.5.1
There is no problem, however simple, that cannot be made more complicated by thinking about it.