Live Z Issues
Just completed an insulated enclosure to help with ABS. Moved the printer in and re-calibrated. With the door open ran a PLA print and all was well. Tried an ABS print with the door closed and had some first layer issues, so I went through the steps in this post:
https://shop.prusa3d.com/forum/prusa-i3-kit-building-calibrating-first-print-main-f6/-before-you-ask-troubleshooting-video-updated--t472.html#p39190
Specifically, re-ran xyz, ran z, centered and adjusted live Z with a piece of paper. Started dragging at -.245 so I dropped it to -.2. Pre-heated for ABS and then started a first layer calibration test (75mm x 75mm 1 layer square). When it started to print the nozzle was WAY above the bed. I had to the drop live adjust z to -1.2 (out of the comfort realm from that post) just to get something reasonable. Stopped the print to get rid of the rats nest, pre-heated ABS, and then tried the same file. The nozzle is back to way above even with live z now at -1.2. It is like it constantly gets farther from the bed every time I initiate a print. The enclosure sits around 100 Fahrenheit with the door closed. Could the temps be messing with the PINDA or should I be looking elsewhere?
Re: Live Z Issues
The MK2 PINDA is temperature sensitive. The new one for the MK3 has a thermocouple inside so it can calibrate that out.
If the enclosure gets too warm, the fan that cools the heat break will not be able to keep the filament solid in the heat break, and it will be soft and cause a clog. It is a balance with enclosures. Warm to keep the print from warping, but cool enough to keep the heartbreak cool.
Any advices given are offered in good faith. It is your responsibility to ensure that by following my advice you do not suffer or cause injury, damage or loss. If you solve your problem, please post the solution…
Re: Live Z Issues
Thanks for the fast response! Copy that, can that be swapped into the mk2? Perhaps before I go that route does this sound like a PINDA issue or are there some other things I should try trouble shooting as well?
Do you know at what temp the hot end would become a problem in an enclosure? I haven't managed a long print yet so I don't know what it will really get up to.
Re: Live Z Issues
At the moment the Mk2.5 upgrade includes the Pinda probe V2 but it is an unknown what the probe's temperature sensor will connect to.
Re: Live Z Issues
Gotcha. Another noob question, wouldn't the PINDA struggle on every first layer if the bed was at ABS temps if it is that sensitive? Before I built the enclosure I had a "successful" print in ABS (warping, but it was in a drafty room). Seems like being sub-millimeter away from 100-110 degrees would still cause a problem if that is what I am experiencing.
Re: Live Z Issues
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Gotcha. Another noob question, wouldn't the PINDA struggle on every first layer if the bed was at ABS temps if it is that sensitive? ...
no, it takes a few minutes for the pinda to heat up.
that's why the recommended procedure for a good mesh bed levelling (invoked by the G80 command), to determine the distance between the probe and the bed, is to "park" the extruder (with the pinda) high above (at least 10 cm) the printbed.
furthermore it's highly recommended to let the whole printer "cool down" before starting a new print. so that you always get the same starting conditions, as good as possible.
but at all, this problem should be solved with the pinda2, and a firmware to compensate the temperature sensitivity.
that's why I'm looking forward for the MK2.5 upgrade kit as well.
dem inscheniör is' nix zu schwör...
Re: Live Z Issues
Awesome, I will give it a try!!
Re: Live Z Issues
I re calibrated everything and then ran a test surface like the one you made (Started from 100mm off the bed. Live adjust z needed some tweaking but I got the layer to finish pretty well. Let everything cool down, moved z up to 100mm and then tried to print the test surface again. Nozzle came in way above the print surface again. Could I be dealing with another issue? I didn't have anything like this the first time I printed ABS.
Re: Live Z Issues
Also remember the hot end cooling fan blows hot air all over the PINDA probe. So it does not just get heat from the bed.
You are not alone in the issues you are having. I have similar issues.