I got my Sovol Zero this week and the first prints were a little bit disappointing. I am fighting with Z banding and overall bad print quality. I have already slowed down the speed to 200 and accelaration to 4200 fllowing the input shaper recommendation. I have calibrated flow and pressure advance. Searching for the problem I found two possible issues:
X and Y are not really running smooth when moved by hand. I tried to apply some of the supplied grease, but this did not make things better.
The belts are not running in parallel with the x gantry. Is there a Fix for this?
What filament are you using…PLA, PETG, ASA…and what brand…
What are the hotend temps your using…
Can you post a few pics of your print…
Is this your first printer…
Did you try a print before changing the settings..??
Thanks for your quick response!
I am printing with Sunlu PETG at 240°C hotend and 75°C bed. The Zero is my third FDM printer. I already own an AM8 and a Two Trees SP-5. I just wanted an additional solid printer for ABS and ASA.
I did my first prints with stock settings and the Sovol profile for OrcaSlicer. Those prints came out really bad, with massive Z-banding and ringing. With lower speeds the results are better, but the Zero is still not able to match my AM8 in terms of print quality.
The belts don’t need to be parallel to the X axis gantry. They should be closer to the gantry rail on the edges and a few millimeters farther away from the gantry near the print head. It looks a bit wonky but doesn’t impact print quality.
What about the motion control system fundamentals?
With the power off, you should be able to move the print head by hand, in the X and Y directions. The motion will be slow and should require a pound or two of force to move at a steady 100 mm/s speed when back driving the motors. The force should be nearly the same in the X and Y directions and maybe slightly less on 45 degree directions. The force should be uniform across the full range of motion. It shouldn’t become easier or harder to move. If it does, the rails may be misaligned or bent. It shouldn’t feel gritty. If it does, wipe the linear rails with a light synthetic oil and a lint free towel to clean it. I use RemOil, but TriFlo or similar oil should work. Avoid WD40 as it oxidizes and becomes gummy. Wipe off the oil and apply a thin coating of light synthetic grease. You should have a small tube that shipped with the printer. Manually move the print head several times across the range of motion to distribute the grease into the bearing blocks and then wipe most of the grease off the rail. You want a thin film. Moving the print head by hand should now feel smooth.
Is the print head firmly mounted? You shouldn’t feel any wiggle when applying force to the sides of the print head. The blue plastic shroud should wiggle a bit but the print head itself should be firm with no discernible play.
The hot end should be firmly attached to the print head. You shouldn’t be able to feel any play when pressing the nozzle from side to side, or front to back.
Pluck the two belts in a few similar/mirrored locations. The belts should be fairly taught and both belts should produce a similar low frequency damped thud. With the print head to the far left, you should be able to press each of the timing belts against the X gantry with a few ounces of force.
Ensure the belts and pulleys are clean and free of debris. A missing belt tooth or a clogged timing pulley valley can cause the print head motion to briefly lag or surge although repeating banding is more likely a pulley defect than a missing belt tooth. Move the print head manually while inspecting the timing pulleys. There are two on each back corner, one on each front corner and two at each end of the X gantry but those bottom pulleys are difficult to see. The pulleys should run true and not be bent or loose. Try to see if the two drive pulleys in the back corners, on the stepper motors, are securely fastened to the motor shafts. A loose set screw could cause a few degrees of slip whenever that motor changes direction. Keep in mind that each motor alone moves the coreXY print head diagonally, so consider that when looking at the print defect and trying to infer what motion control problem could cause the observed print defect.
Try putting a small machinist square or something similar on the Y axis linear rails behind the X axis gantry and look down from above to ensure that the X axis gantry appears perpendicular to the Y axis. The Zero is a tough little printer but if the shipper dropped the box on a corner it’s possible that the frame could be sprung so the axes are no longer orthogonal.
Good luck! I hope you can fix your Zero because it’s a great little printer and should be cranking out very precise parts. You definitely should not have the print quality defects shown in the image you provided.
For further troubleshooting I did a print with Sunlu PC-ABS yesterday and the result was much better than my previous prints with PETG. I did not expect this because the prints did not look like bad filament in my opinion.
Before I start to check to whole Zero I will test this spool of PETG with one of my other printers.
I dry all my PETG in a Sunlu S4 prior to printing. Most of the time I print directly out of the S4. If the results are as bad with my other printers, I will give this spool an extra round.
-replaced the belt mounts for these: FIX Sovol SV08 Hot End Belt Clip by Laut Indah Mandiri | Download free STL model | Printables.com
-Cleaned X/Y rails with iso propranolol and applied some high heat/ high pressure grease
-Checked all idlers without belts, but they were all good and smooth
-Tightened the belts a litte more than before and double checked same values for both belts with my Belter tool.
-Tightened all screews I could find
-Fine tuned the printer and reduced scv to 4.5.
-Recalibrated input shaping
Print looks good now and I am focusing on fine tuning PA, cooling, speed and acceleration.
If your printer is on a table or surface that is not rock solid you might try moving it to the floor and then try input shaping again. If you get dramatically better results it might be worth finding a better table or improving the stability of what you have with bracing or anchoring,
Those replace the clamps at the print head. (The picture @MikeHides posted shows the correct parts) They are almost identical to the original ones. The holes are just 2 mm off center. Because of this, the belts are pushed toward the X gantry and aligned with the position of the idlers. Without this modification, the belts are not in line and form a triangle. This leads to different belt tension depending on the X position of the print head. If you take a look at the .stp file provided by Sovol on GitHub, you can clearly see that this is an error in the printer’s design.
Replacing the clamps is an easy 5 minute job. Just loosen the belts and remove the 4 M3 screws at the clamps. Remove the clamps from the belts and attach the new ones (The just slide in, the side with more distance to the holes must face the x gantry. I have mirrored one clamp while printing. This way the thicker side of the clamp can face the screws on both sides of the print head). Attach the clamps to the head using the original screws and tighten the belts.
I found another problem with my printer. The input shaper configuration only analyzes a narrow frequency range. Extending the range revealed a main peak at much higher frequencies:
Another change I made: After cleaning the nozzle before a print, the printer cools down to 130 °C before calibrating the Eddy probe. To accelerate the cooldown, the part cooling fan is set to 100%. I extended the nozzle cleaning macro to enable the auxiliary fan as well. This saves a few seconds for every print.
