Squiggly extrusion along diagonal lines
Lately I have been experiencing subpar print quality, so I have been browsing around this forum for shared experiences and answers. I came across this great post about an alternative first-layer calibration method, and I gave it a shot with a simple OpenSCAD design [1]. As you can see in the first attached video (link in case the video is not rendered inline), the diagonal lines are not completely straight, but have some irregular waviness:
Once the print completes, I take the print sheet out and evaluate how even did this single layer print result, as shown below (link in case the video is not rendered inline):
It doesn't seem as smooth as you could expect. Can you give me some advice on what else to tweak on my Mk3S? Things I have done already:
- Taken apart and cleaned the entire extruder, also added thermal grease to the hot/cold end coupling screw.
- Tightened all bolts of all axes.
[1] OpenSCAD design source:
cube ([75, 30, 0.2]);
Best Answer by Neophyl:
Waviness can be either too far from the bed or too close. However along with the drag marks around the edges I'd judge it is too close a live Z. Back it away from the platter a tiny bit and print again. Its a very fine line between too far, too close and perfect. Also be aware that the PINDA sensor is temperature sensitive as well as the bed physically expands when warmed through changing its position means doing a live z calibration from 'cold' to ones later once everything has gotten 'warmed up' will cause a difference.
RE: Squiggly extrusion along diagonal lines
Waviness can be either too far from the bed or too close. However along with the drag marks around the edges I'd judge it is too close a live Z. Back it away from the platter a tiny bit and print again. Its a very fine line between too far, too close and perfect. Also be aware that the PINDA sensor is temperature sensitive as well as the bed physically expands when warmed through changing its position means doing a live z calibration from 'cold' to ones later once everything has gotten 'warmed up' will cause a difference.
RE: Squiggly extrusion along diagonal lines
Thanks for your answer @Neophyl! I read about the temperature sensitivity of the PINDA sensor, however, I understand that for MK3S+ (the printer I got), Prusa upgraded the sensor to the SuperPINDA, which should have done away with the temperature sensitivity. Also, I want to stress that I was getting very good prints up until a month or so, then I ran into this issue, so I guess that sensor is not the problem...
I'll try adjusting the Live Z spacing, and get back to you.
RE: Squiggly extrusion along diagonal lines
I finally got the chance to finish this business off. I had looked up and found other forum posts about printing problems caused by the belts' tension being off the proper value, and I thought I had not tested the tensions since I assembled the printer! So I gave a shot at the nice tuning web app featured in this article, and the diagnosis was that my Y-axis belt was loose. As I got to correct that, I saw that all screws of my heatbed were loose! So my heatbed has been cavitating to the vibrations from the motors, and the Y-axis belt being loose was just the cherry on the top.
After fixing all that, I did my calibration print again, and soon after starting, I saw I was no longer getting squiggly diagonals! Then I made sure to heed your advice, which was on spot because the first lines were visibly pushed into and around, and as soon as I adjusted the Live Z a bit away (changed it from -1.303 to -1.175 mm), the layer looked nice and uniform!