Multiple Printing Issues - Suspect they all go back to a Y axis belt
I'm having multiple printing issues on my MK3.9. Some are definitely Y axis issues and I'm sure that's got a lot to do with the belt, but I wouldn't be surprised if they all tie into the Y axis belt. I had some similar issues a few weeks ago and adjusting the tension on the X axis belt finally fixed them, but it's also a lot easier to adjust the X axis belt (and a wider range of adjustment for it) than the Y axis belt.
Before I get into the issues, I've used a Belt Tension Meter to check on my Y axis belt tightness. According to that, I'm at the high end of the range (close to too tight, but not at that point). I've also used Prusa's web page for checking tension by strumming the belt. That reads that I'm right in the middle of the range. After a discussion about this kind of issue with the X axis belt, I've learned not to rely on the LCD readout on belt tension. Others have said it's not too accurate and my experience bears that out.
Even when prints turn out mostly decent, I'm having issues with the filling coming out evenly:
I find that I can change the infill type and that issue often goes away:
However, what I find interesting is that I'm having an issue where there are rough waves on the top layer, in the same areas where the infill has not come out well:
Also, I've noticed a concerning sound during printing that I can best describe as a cross between a grinding noise and flatulence (to avoid language issues - pass gas or fart would also work there).
Then, for the past 4-5 prints, I've had problems with an axis shift. It's small and always the same amount and at about the same layer in printing:
What's odd is that I've had this issue multiple times and always at the same layer height (give or take a layer - hard to tell for sure, since I'm usually not able to be at the printer while it's printing.
I'm sure the layer shifting is relate to the Y axis belt, and suspect the rough spots are due to an uneven tension in the belt, too. I've looked over the belt and I don't find debris in it or dirt. I've checked for obstructions, since I've recently done the 3.0->3.9 upgrade and that included doing more cable routing and I've changed my OctoPrint systems from one Pi4 to a Pi Zero 2 W on each printer, so that meant some new cable routing, but I've checked to make sure there's no cables that come near the drive belts or could create a problem with movement.
Could my issues with infill and the rough waves on the top surface be part of this? What else can I do to deal with what seems to be a y axis issue? I do have a long loop of the same type of belt as used on the X and Y axes. I was thinking of just trying to loosen the Y belt by one notch where it's anchored to the print bed, then adjust to tighten it again. Also, I notice that when the printer is not working and I can manually move the print bed, it doesn't seem to run into obstruction of movement.
RE: Multiple Printing Issues - Suspect they all go back to a Y axis belt
It would help me to know why I'm not getting any suggestions here. Is my post unclear? Did I provide too little information or am I contradicting myself? Or is it just that it's not clear what else I could look at to solve this issue?
First deal with the warping, it might not be causing your issues but it's may be masking the causes and contributing to the shifts.
So: clean the print sheet, add brim and make ure you aren't printing in a draft. I presume you have cleaned and lubricated your smooth rods?
Cheerio,
RE: Multiple Printing Issues - Suspect they all go back to a Y axis belt
First deal with the warping, it might not be causing your issues but it's may be masking the causes and contributing to the shifts.
Good point. My thought was that if the belt is having issues, it could be causing the warping, but you have a good solid point.
So: clean the print sheet, add brim and make ure you aren't printing in a draft. I presume you have cleaned and lubricated your smooth rods?
Ah - cleaned 'em and forgot to lube them recently. Now that I think about it, it's been a while. Got into the habit of cleaning and not lubing them. The print sheet is clean and there are no air vents and nothing that feels like a draft there. The work I'm doing now is part of a ventilation system that'll let me put vent hoods over my printers and my CNC system (which produces smoke when the laser is used). That'll help me make sure there are no drafts (and if I'm using ABS filament, I can vent the printer enclosure when the print is done).
I'll do a clean and lube of the rods tomorrow and I have a 2nd print sheet and I'll swap it out. (Which means recalibrating the Z offset again, but that's not a big deal since I went up to the MK3.9 and it prints so much faster.)