Hi, A bit stumped on the following issue. After running bed leveling from the LCD the head will crash into the bed. This happens even while the bed is nearly good enough to print on after autohoming (which I'm doing currently). (Aside note: at some point the bed leveling also worked reliably). A bit more history and things I tried: I received the Z fix parts and mounted them and verified the Z is smooth. Calibrated the Z offset so after autohoming a piece of paper fits snuggly between bed and head. All seems well.... Run bed leveling from the LCD. Start print and see that the head is pushed into the bed, cut power to abort things ASAP. Did various things like tweaking Z offset untill I noticed the problems only occurred after bed leveling and that the Z offset was actually not the issue. My test procedure is currently: auto home level bed move Z-axis in 0.1mm increments up repeat in other positions while using the LCD to move the head in X and Y I assume that if things are well I should not be able to crash the head into the bed. I can move the bed +/- 0.2mm 'into' the head. Things I tried: I took the rods/bed out once more and rebuild it so it's as tram as is possible. The Z moves really buttery smooth also when moving it slowly at the top of the rods, no snags. Verified this without the lead screws, and ran the bed up and down many times while watching the bearings if they were snagging (obviously with leadscrews ). No change in the behaviour. I had been using pritt stick glue on the glass so far. Double checked that the calibration points were similarly 'glued' so reflection should be the same. No improvement. Clean the glass completely, rinse repeat, no improvement. Put paper beneath the glass, rinse repeat, no improvement. While writing this I realized I did not test with paper on top of the glass. In this case the head stays wide away from the bed. So it seems the IR sensor 'kindoff' sees the glass bed. Anyone have any thoughts on this? Ric PS: I did not try fiddling around with the instructions on the page of that describes this particular probe (https://miscsolutions.wordpress.com/mini-height-sensor-board/) PPS this is on a single extruder Bigbox.