Maybe another rookie will read this and avoid my mistake. Altmill 4x4 is assembled and all seems to be working fine. I’ve surfaced my spoilboard and cut out a test project by manually zeroing. I updated to gSender 1.6.2 and was setting up the AutoZero touch plate. The config screen in the new version of gSender does not match the instructions currently published in the Altmill assembly section on the web. I matched the settings as best I understood them (again the config screen in 1.6.2 doesn’t match instructions). Nevertheless I failed to change the final Z retract which was set at 1mm on my machine. I went to do a test probe which went fine testing XYZ until it completed, withdrew 1mm in Z and moved toward the back left position while I was set on front left. It drove the bit down into the block and shattered the bit. (The shrapnel created could have easily injured an eye so keep those safety glasses on!). I then looked at the probe screen and noticed that I had not selected front left position. I didn’t even notice the selection option. Please be aware of the position selection option while learning this process. And change your Final Z retract for safety considerations.
This seems to trip up a fair number of people but I don’t know what could be done to make sure that the operator verifies this other than learning through the school of hard knocks (and broken bits).
I had that experience as well but in my case it just pushed the AutoZero around a bit because I was only setting x/y. Since I always put my z zero at the spoilboard level, it is very rare that I use the AutoZero for z. … I lucked out.
There is another thread where somebody asked if they can slow down the last movement from probing to x/y/z zero. I don’t know if this would have helped but it would possibly give the operator a chance to hit the emergency stop. Doing this move at full speed doesn’t really save time. If this was adjustable, I would probably slow it down by 50%.
Ironically I was literally just watching video on ncSender about this which appears as though it does have safety feature that prevents this from happening:
