troubleshoot error during print
I'm running an mk3S and using prusaslicer 2.7.1 (just upgraded slicer, all the filament files, and the firmware on the printer a few days ago actually). After all the upgrades everything worked great and printed a few items. Today, I made a new model and I'm getting a weird error printing. As you can see in the print, at about the end of the fourth horizontal layer it literally moved the entire print area on the Y axis. When I first saw it I thought the belt had skipped a tooth, so I checked that and it is fine. I re did the program in Slicer and it doesnt indicate any issues so I tried again and watched... about 26 minutes in, it retracts the hotend, goes to what looks like 0,0, then returns to printing... except now the Y axis is off and the print is ruined.
Any thoughts?
RE: troubleshoot error during print
Here's the .mf file
RE: troubleshoot error during print
That's a classic axis crash. Usually caused by the part warping upwards (long thin parts like that are more prone to warping) and then the extruder comes along and crashes into the part and loses it place on the axis so the rest of the print is shifted over. There are hundreds of threads here on the forum with similar.
If you look at the bottom of the part I bet that you will see it has warped up, put it against the flat edge of a ruler and check.
If that is the case then you need to look at increasing part adhesion. The usual really clean bed and dialling in the live z . Followed by adding a brim, controlling external temps/possible enclosure to reduce drafts and temperature differentials etc. You could also try a different infill than gyroid. I avoid it on parts like this as I find it increases the chance of a part warping. Try cubic instead.
If the part design allows it you could also add in stress relief holes or slots to break up long straight runs.
RE: troubleshoot error during print
Thanks for the suggestion Neophyl, but I dont think that was or is the issue. The two failed parts havent warped off the bed. I've had some parts warp pretty bad using ASA filament and even then I didnt get this kind of issue. Just out of curiosity, when the error you describe does happen, does the head retract from the print, go to 0,0 and then return to printing (albeit at different point and now shifting the entire axis)? I observed mine doing that.
Anyway... to try and sort this out I started re-running all calibrations and surprisingly it failed on the Y belt test. Remember I'd checked that and thought it was fine? lol Handy little app on the prusa help page for literally tuning that in. It took a few tries to get through all of the other calibration steps but I think that was my fault for not running them in the proper order (calibration flow...follow the instructions dummy). Got a pass on all eventually and I've printed two little parts that have come out great... going to try a bigger one today.
RE: troubleshoot error during print
More prints, same error. You can see the part hasnt warped off the bed and yet the X axis has moved twice during the print.
RE: troubleshoot error during print
Different file though similar shape, and this time the X axis shifted by a ridiculous amount!
RE:
If the parts aren’t warping then the other common cause of a crash on an axis is sticky bearings, do they move smoothly in both directions when moved by hand ? Do you feel any resistance at any point ? I presume you follow a maintenance routine and lubricate them periodically?
The built in ‘belt tension’ numbers aren’t actually tension, they are measurements of motor current, which for smoothly running bearings are analogous of tension as that effects motor current required to move an axis. It’s not tension in reality though as other things can cause increased current usage.
and yes a crash for any reason causes the printer to re-home and attempt to continue as long as you have detect crashes turned on in the settings.
RE: troubleshoot error during print
Thanks for that detail Neophyl. The bearings feel smooth to me. The machine is a year old but honestly doesnt see anywhere near the amount of use that I know some on here put their machines through.
I downgraded the printer firmware to 3.12.2 and re-ran the same file from that last picture and it printed beautifully. I then printed several other smaller pieces and all those are good. So... either I have a hardware problem that only happens occasionally or somewhere between 3.12.2 and 3.13.2 there is a bug that occasionally causes an axis shift?