Z-Axis Crash into Bed
I was re-running the 'self-test' after solving the y-axis issue I was having (already posted this solution) and the z-axis movement in the script was reached where the printer proceeded to lower the extruder into the bed without stopping. This is where I had to cut the power to the unit as I did not think the unit was going to stop on its own. Can anyone tell me what I am missing here? I do not see a mechanical end-stop in the z-direction and I don't remember installing one. Is the probe on the extruder head the means for "sensing" the printer bed? Is there a black cap on this probe that is blocking the sensor and is required to be removed? Thank you!
Re: Z-Axis Crash into Bed
Do not make such a thing!
Re: Z-Axis Crash into Bed
The black part is the sensor itself. This is caused usually because the PINDA probe is too high. Put it lower, it should be about 1mm above the nozzle end, at max. Once the probe is down enough, it will react on spot on the bed and stop it.
Also check that the probe is working at all. There is a red light on the top of the probe, put some metal thing under the probe and the red led should stop.
Milos.
Re: Z-Axis Crash into Bed
One more thing for the future. You made right decision to stop the printer when it starts to crash the bed. But to stop the printer it is better to use the Reset button. It is the only button on the LCD panel, with X.
It will stop and reset the printer. Much better solution because specially when you are already printing and the hotend is hot, it will should down the fans just for a couple of seconds. If you switch the power off and leave it, the filament can get jammed in the hotend. It is necessary that the hotend fan is running till the temperature goes back bellow 50°C.
Milos.
Re: Z-Axis Crash into Bed
Thanks, Milos! Prior to reading your post, I moved the probe down and this resolved the issue. I thought I followed the assembly instructions very carefully. I must have missed the instructions on setting the depth of the probe or misinterpreted the dimension. I recommend for future Prusa designs to maybe incorporate a load sensor of some kind to shut down the power upon such an impact. The bed is now damaged, but still useable. Thanks again!
Re: Z-Axis Crash into Bed
Yes, the assembly guide is a bit unfortunate. It describes how to allign the top of the probe. But the top of the probe is just some transparent plastic foil and you do not know if to allign the foil or metal edge. If there would be note about height relative to tje nozzle and very strict warning for first calibratiom attemp to watch this and stop as fast as possible, a lot of beds would have survived. It happend to me as well during assembly, but I was lucky to stop soon before any damage.
Milos.