Auto-Squaring UCCNC

[Kitwn]

When I recently moved from using LinuxCNC to UCCNC it was said that it is not possible to auto-square a two-motor axis using software settings in UCCNC as it is in LinuxCNC. I've done some test today to show that this is not the case.

When using UCCNC to drive a two-motor machine, the long, dual-motor axis is designated as X (or Y if you prefer for some odd reason) and another axis (typically A) is slaved to it. The screengrabs below show the setup for my machine. Separate limit sensors are used for homing the two sides of the gantry and a "Back off" distance specified for each. You should aim to make your machine square itself as accurately as possible with the two back off distances set equal. This is done by adjusting the position of one of the limit switches. However, axis A does not become a complete slave to X until after the back off move is completed which means that fine adjustment of the squaring can be done by making the back off distances slightly different. UCCNC will only let you enter back off distances to an accuracy of 0.1mm which is probably adequate for most of us. If not then I'm sure we could pester the makers to allow an extra decimal place.

Tests were done today by fixing the X back off and making small changes to the A value then re-homing the machine and confirming that A moved to a different finishing position and X stayed the same. Changes in multiples of 0.1mm were confirmed possible.

Kit