when printing I randomly get y-axis crashes even though there is no real "crash". The printer then auto-homes and continues to print.
The printer is in stock form, no mods or anything. I have added the raspberry pi zero option but the issue also happens with SD-card and before installation of the pi zero. The bed is moving smoothly by hand and via the menu. Contrary to the x-axis you can feel the little steps on the y-axis when moving but I read that this is normal. The belt tensions are x : 230 and y : 266. The rods seem all fine, I checked them for damage. The bearings were installed as stated in the manual. Also the printer calibrates and self-tests without issues.
I operate the printer in an enclosure. The temperature in the enclosure gets around 28-30 degrees during the print. I can definitely confirm that the bed or the cables are not squeezed or touching the enclosure. Everything can move freely.
When "crashing" in the enclosure I get layer shifts and weird stringing (s. pictures below):
When I print outside the enclosure, I somtimes get random y-axis crashes, but they are not noticable in the print as no layer shifts or stringing occurs.
FURTHER INFORMATION IN THE WEB
It seems like there are lots of people with the issue and lot have been tried.
WHAT DID I TRY SO FAR
Some stated, that the mainboard can be overheated and needs to be cooled. I bought an USB fan and pointed it to the mainboard during the print but had no success.
Further I added some little lubricant on the rods but also no success.
Some say that the bearings extend when they get warm. Others say the y-axis motor gets too hot. I can confirm that it gets quite hot but the x-axis motor has the same temperature by feeling with the hand. And generally I don't really have that much of anhot environment. As said the enclosure gets around 28-30 degrees and it is not fully closed (door has spaces around it).
I would really like to understand the root cause of this issue.
Forgot to mention: It is a mk3s+ kit, around 1-2month old. I don't know if I had the issue since the beginning or later as I just recently put it into the enclosure and noticed the issues with the prints.
I don't have a solution for you, but see some thing I have noticed with using OctoPrint myself.
The failures counter doesn't get reset when you print using OctoPrint. The counters only get reset after when starting a print from the sd card.
So I may be a good idea to do you troubleshooting using the sd card. That way you will know for sure if the crash happened on the last print.
The total counter increases by 1 when multiple y-axis crashes happen per print. And the last print y-axis crashes counter changes only, when crashes happen. It will stay the same when there are no crashes or if the amount of crashes is the same as the last defective print. But the total counter allows me to see if crashes happened.
Enclosure - open the door
Unless you are printing ABS or some other high temp material, first suggestion is open the enclosure door and keep it open. PLA won't print reliably at high temps and PETG will overheat at the temps you list. Open the door unless you are printing ABS.
If you got layer shifts you will get crashes. Work on the layer shifts and the crashes will be reduced. The crashes do NOT cause the layer shifts but a layer shift can be caused by a crash. If this is the case you are definitely crashing - do believe it.
Crashes happen when the nozzle hits already cooled filament. Poor adhesion is the # 1 cause. Oil on the print bed is the #1 cause of that.
As I said the issue also occurs (but less often) when I print outside the enclosure.
Further, the layer shift is caused by the crash not the other way round. As I also said the I sometimes have layer shifts after the crash in the enclosure, but never had layer shifts outside of the enclosure when the crashes happened.
Adhesion is no issue at all. I had never issues with it and I make sure that my sheets are properly cleaned before printing.