First Layer Height Intermittent [Live Adjust Z]
Aloha Folks,
We have two i3 Mk3S printers that were donated to our school. One prints beautifully without issue 99.9% of the time. The other is a hot mess, literally.
The other printer, however, is not consistent at all. It seems to me that when calibrating the Live Adjust Z, I bounce between -0.1 to -0.5 values intermittently. For instance, I run the Live Adjust Z calibration function from the menu and I find a nice first layer adhesion with a value of -0.5. I then immediately run the calibration again find that the nozzle is practically scraping across the bed and have to change the Z up to around -0.1 where the rest of the test print works out well. I then again run another Live Adjust Z calibration and find it is not adhering to the bed well and have to adjust the Z back down to -0.5. I bounce back and forth between these two values intermittently so I am flummoxed as I can find no rhyme or reason.
I am guessing that whoever had originally assembled the machine did a subpar job as one of the first issues was that the extruder motor seemed to have failed but on closer inspection I found that the set screw needed to be tightened down. Some of the 3D printed parts on the hot end showed signs of damage and warping so I decided to reprint all the parts and rebuild the hot end which I have done but I still get the same behavior.
I've read in other posts that it may be a temperature issue and some folks have had success with modifying the gcode to pause a minute after homing and before the start of the print to 'stabilize' the temps but this did not help me nor did it make sense as I have another printer sitting right next to it that needs no such provision. In another post, someone had suggested replacing the PINDA sensor but I am wondering if there is anything else I can try before purchasing replacement parts.
Any suggestions or insight are welcome, mahalo!
Switch build sheets with the other machine, run a new first layer Z calibration and test print; does the problem follow the sheet?
I am guessing that whoever had originally assembled the machine did a subpar job
Impatient and incompetent builders are more likely to pass on the machines they messed up. Usually fixable.
Is your PINDA loose in it's mount?
Are the Y smooth rods secure?
It may be worth contacting Prusa Support: Log into your Eshop account, navigate to Help and live chat is at bottom right in most browsers. If not you may need to disable your ad-blocker temporarily.
Cheerio,
RE: First Layer Height Intermittent [Live Adjust Z]
One other thing I would check is to be sure that all electrical connections are tight and secure, and that the cable for the Pinda is physically OK, as in not bent anywhere at an angle where the conductors might be damaged or frayed, etc.
It sounds to me that this may be a Pinda issue. As noted above, be sure it's tight and solid in its holder.
It could be an issue with the Pinda itself, or in the Einsy board, but I would first check the cabling to be sure it's physically un-damaged and everything is secure.
It might also be good to double-check all mechanical items, such as be sure the belts are tensioned and that those trapezoidal nuts on the Z axis mechanism are in good condition and do not have any slop or play in them.
RE: First Layer Height Intermittent [Live Adjust Z]
Thanks for the suggestions.
The PINDA sensor, Y rails and bed feel quite solid and secure.
I tried using the build sheet from the other printer but it still exhibits the same behavior.
I will try support.
[SOLVED] RE: First Layer Height Intermittent [Live Adjust Z]
Aloha Folks,
I just wanted to update this post for any future folks who may be in the same position.
I connected with Prusa support and they linked me to a document that assesses the status of the PINDA sensor:
https://help.prusa3d.com/article/p-i-n-d-a-superpinda-sensor-testing_2091
Executing the steps in that document demonstrated that the PINDA sensor was/is functioning within normal parameters.
Support then linked me to another document outlining steps to complete a factory reset:
https://help.prusa3d.com/article/full-system-refresh-original-prusa-i3_133258
Executing the steps in that document seems to have mitigated the issue.