What is the problem? I still get an occasional random layer shift of 1mm in the Y axis even after curing the majority of my previous layer shifting issues.
What did you already try to solve it?
I’ve been using my Tevo Black Widow for about 6 months. It has the typical add-on corner braces etc. plus a thin glass on top of the bed. I have experienced some layer shifting problems and solved some of them by, for example, discovering a loose belt drive pulley grub screw. But I haven’t completely solved my layer shifting problem. I’ve changed to 2130 drivers with large heat sinks (in Stealthchop mode), changed stepper motors on the X, Y, and Z axis, removed and hard wired some of the stepper motor connectors, replaced the cheap plastic pulleys with good aluminum ones, upgraded the belts, put Locktite on the pulley grub screws, added a dedicated driver cooling duct with a huge radial fan, installed a larger control box cooling fan, etc. I even replaced the printer control board.
I’ve also fiddled with the Vref voltage and I have increased it to the point that an axis will stop presumably because of overheating. I’ve also turned the voltage down to the point where the stepper motors consistently skip steps. At the moment I think I’m OK with the Vref setting. When I touch my stepper motors after hours of printing, I have to hold them a while to determine that they’re barely above room temperature. They’ve never even gotten close to warm, much less hot. I can’t touch the drivers because of the cooling duct, but the duct exhaust air is very cool.
I’ve checked the friction on all the axis. Everything moves smoothly, quietly, and without any significant friction or sticking.
I’ve always used Cura on a Windows 10 desktop in the next room connected to my local WIFI. I send the print file via WIFI to a conventional OctoPrint/Octopi attached to my printer in the next room. The printer/Octopi rig is powered by a large uninterruptible power supply.
I’ve tried reducing speed, acceleration, and jerk settings way down and that, along with my other attempts at fixing the problem, seemed to eliminate the most serious layer shifting. Lately I’ve made some 8-hour prints which were perfect. But then this morning I had another layer shift after printing for only about 30 minutes. In other words, I think my earlier frequent layer shifting problems in both the X and Y axis were caused by overly aggressive software settings along with some solvable hardware problems which I took care of.
Now most prints are essentially perfect but there is still a problem with an occasional layer shift which occurs exclusively in the Y axis. The shifting seems to be completely random with no association with long prints or small parts or difficult moves.
At the moment I’m trying a print directly from an SD card for the first time. I have not tried printing with OctoPrint in the safe mode and I have not tried a slicer other than Cura.
Question: Where does the print data go once it leaves my desktop? Is it stored on the micro SD card in my Octopi or does it pass directly to the SD card in the Tevo Black Widow printer control box? Or perhaps it does something else.
These layer shifts are mostly single shifts of about 1mm and occur in only about 20% of the time. That’s an improvement, but obviously still frustrating especially after printing for 8 or 10 hours.
Could Cura be corrupt and inventing these random, occasional layer shifts?
I’m wondering if a corrupt SD card could be the problem.
Is it possible for the print instructions to become corrupted between the time I send a file out of Cura and the time a stepper motor is commanded to move?
Would a different slicer be worth a try?
Additional information about your setup (OctoPrint version, OctoPi version, printer, firmware,
serial.log or output on terminal tab, ...)
Octopi 3 B running the current version of Octoprint. Marlin 1,1,8 BLT