Michael,

I hope this thread will help you get LinuxCNC 2.8 up and running without any problems.
One thing to watch out for that is mentioned on the LinuxCNC forum regarding the auto-squaring is that the sensors must stay triggered until the software tells the gantry to move again. If the cutout in your drawing were too narrow there is a risk of overshooting the slot during deceleration and resetting the sensor too early.

Kit