Z Calibration Drifting?
Hello All,
Had my Mk3s+ for ~6 months. Really nice printer. I've run into an issue that I suspect is a failing PINDA probe, but I was hoping to get some validation/ideas of other sources.
The problem is that when I start a print, occasionally the printhead will be printing much much lower than the print that just completed. I initially did the live adjust such that the offset was around -1.5mm (quite large I know), which worked great for ~5.5 months. Then suddenly one print was digging into the bed which caused me to raise that offset to about -1.0 to get a good first layer. Again, last night I start a print and the same thing happens causing me to raise the offset to -0.3mm. No other settings changed, same slicer, same settings, etc. I am running PrusaSlicer through RepetierHost and the print is being executed by RepetierServer, FW version is 3.9.3-3556.
As I mentioned, I suspect the PINDA probe is starting to fail, which I gather can happen. Does anyone have an alternative explanation or anything to check?
Thanks for reading
Drift
A slow drift can be normal but it should slow to near nill change.
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Chuck H
3D Printer Review Blog
drift
So a drift of half a mm in between prints is atypical?
Not normal, but may not be PINDA failure
So a drift of half a mm in between prints is atypical?
Definitely not normal. I'd make sure the PINDA probe isn't loose or moving before making too many replacements. Also check to make sure the support arm holding it is aligned properly and not sagging. Depending on the age of your printer, some of the earlier design revisions were prone to sagging.
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He is intelligent, but not experienced. His pattern indicates two dimensional thinking. -- Spock in Star Trek: The Wrath of Khan
R: Not normal, but may not be PINDA failure
Interesting. I attempted to wiggle it after the first shift and it was very secure, however I will double check. As for the age: I purchased it around April or so. Not sure if that pre-data any major design changes.
push
I would gently push it from the bottom and not pull on the wires.
Interesting. I attempted to wiggle it after the first shift and it was very secure, however I will double check. As for the age: I purchased it around April or so. Not sure if that pre-data any major design changes.
--------------------
Chuck H
3D Printer Review Blog
Similar problem here
Hi, it is interesting, I have a similar problem here ( https://forum.prusa3d.com/forum/original-prusa-i3-mk3s-mk3-hardware-firmware-and-software-help/first-layer-flow-problem/ ) but in the opposite way : Z-Axis seems too high each new print (?!)
SuperPINDA or PINDA?
Is yours a PINDA or SuperPINDA probe? Just to confirm: If you let the printer cool off completely between prints, do you still get the same problem? Conversely, if you lower the nozzle close to the bed and warm it before a print, do you still experience drift? The PINDA v2.1 and SuperPINDA were supposed to eliminate temperature variability, but I've been contacted by owners of both asking for help modifying the 2-step warmup procedure I've documented here.
If the behavior of yours has changed, it's most likely a failing probe, but this is worth a check.
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He is intelligent, but not experienced. His pattern indicates two dimensional thinking. -- Spock in Star Trek: The Wrath of Khan
I've seen this a few times. Each time it was the PINDA loose in its holder. Didn't feel like it when I wiggled it but a quarter turn of the screw that holds it in place fixed it every time.
Formerly known on this forum as @fuchsr -- until all hell broke loose with the forum software...
A few leads
Hi All,
I checked the holder and apparently the screw has wiggled out. I resecured the probe and will run a recalibration. If this solves the problem I will feel quite foolish 🙂 The only thing is that if the sensor was loose I would expect it to slip downwards which would result in sensing the bed higher up which would result in the first layer being higher not lower... More testing needed to see if it fixes the problem.
I'm pretty sure it's the SuperPINDA.
Thanks for all the help so far guys!
Doesn't cost anything to just make sure it's tightly screwed in.
Makes total sense that it would drift closer - or further with a loose probe. Imagine the probe slipping down enough to hit your print late in the print - it will knock the sensor higher. Then it slips down and hits at another time... up and down we go. Just tighten the screw and don't over-think it.
Great diagnostic check!
Makes total sense that it would drift closer - or further with a loose probe. Imagine the probe slipping down enough to hit your print late in the print - it will knock the sensor higher. Then it slips down and hits at another time... up and down we go. Just tighten the screw and don't over-think it.
That's a great explanation and a good diagnostic check. If it only goes lower and is not random, check out mechanical issues.
and miscellaneous other tech projects
He is intelligent, but not experienced. His pattern indicates two dimensional thinking. -- Spock in Star Trek: The Wrath of Khan
So far so good...
Hello all,
I reset the PINDA height and re-ran all calibration steps and am printing fine now. I will watch for this behavior in subsequent prints and report back if it crops up again. Thanks again all 🙂