My printer seems to be slowly dying
A couple of months ago, I purchased and built the Mk4S to Core One upgrade kit (I also switched to the obxidian nozzle while I was doing the upgrade) . At first, everything was working well (although I still don't think of it as a fast printer). But after 5 or 6 prints I started noticing some failures. At first I noticed the nozzle would hit the print once in a while, separating it from the bed. Then it would happen more often, and after a few days the head would start scratching the print on the second layer and if I didn't abort the print, it would eventually attach the head to the print and create a giant plastic blob. I switched filaments (from prusament PETG to prusament PLA wood blend), and that seemed to work for a while. Then I started seeing the same symptoms again. at first the contact was minor and it would create some stringing or scratches on the part, but it would still complete the print. And after a few more prints it would start aggressively scratching the print on the second layer and ruining the process. At some point I tried re-running the self tests and calibration and that also failed the nozzle heater test, even though I was able to manually switch the temperature using the control menu without an issue. After that happened I did a soft factory reset and that allowed me to complete the self test and even print a benchie without a problem. But my next print started messing up on the second layer.
Does anybody know where should I start troubleshooting next?
I have attached a couple of pictures and a video that show the second layer getting messed up before I cancel the print
RE: My printer seems to be slowly dying
Here are some more examples
RE: My printer seems to be slowly dying
Usually this happens for several reasons:
- the nozzle is not correctly inserted all the way and tightened in the heat block
- the heat block is not fully inserted into the heatsink
- the thumbscrews are not tight and the heat block assembly slipped down onto the print
- filament is wet and is causing bumps then the nozzle collides with the print
- the print is warping off the bed.
Do you own a filament dryer? Damp filament can cause this kind of issue. I suspect though it maybe related to how the heat block and nozzle are installed.
RE: My printer seems to be slowly dying
I also switched to the obxidian nozzle while I was doing the upgrade
A few questions:
Heatcreep, extruder not able to push the filament through the nozzle:
- how warm is your room?
- is the vent open?
- does it also happen with the door open?
Nozzle issues:
- do you have another nozzle to test?
- is the obxidian nozzle a high flow nozzle?
- are you using high-flow slicer presets?
Extruder issues:
- are your extruder gears tensioned correctly? (compare the screws positions to the manual)
- are the thumb-screws tight enough, but not overly tight?
And lastly, is the nozzle temperature correct? Maybe there's an issue with the thermistor/calibration and the nozzle isn't as hot, as the display shows.
RE: My printer seems to be slowly dying
I also switched to the obxidian nozzle while I was doing the upgrade
A few questions:
Nozzle issues:
- do you have another nozzle to test?
- is the obxidian nozzle a high flow nozzle?
- are you using high-flow slicer presets?
My answer to the obxidian nozzle was going to be "of course it is". But I double checked my original order and turns out I did purchase the regular version. SO that is definitely a problem, since I told the printer I have a high flow nozzle. I will remove that option and re-install the nozzle for good measure and will check again.
RE: My printer seems to be slowly dying
I replaced the Obxidian nozzle with the original brass one that came with the MK4S and so far I've been able to do one successful print. I'll keep printing stuff in the next few days and will keep this updated. In the meantime, thanks for the suggestions!
RE: My printer seems to be slowly dying
After a couple of successful prints, it's back to its old behavior. Head scratches the print and ruins it. I'm starting to wonder if there is something wrong with how the nozzle and heat block are held in position inside the head. I tried to tighten the thumb screws as hard as I could when I replaced the nozzle.
RE: My printer seems to be slowly dying
For what it is worth, a picture of the hotend might be more useful. You shouldn't need to tighten the thumbscrews significantly to ensure that the nozzle stays put. The Nextruder nozzles have two grooves in the heatbreak tube that the thumbscrews should be engaging. Follow the instructions in the assembly manual to be sure that the nozzle is properly seated prior to tightening the screws and you should be able to rule out the nozzle movement as a source of your issue.
Regards,
Steve
RE: My printer seems to be slowly dying
I assume you solved the problem with the second layer by using the appropriate nozzle or adjusting the HF setting accordingly.
To solve the problem with the first layer, wash your steel sheet with hot water and a drop of dishwashing liquid. Your first photos clearly show that the plate is not clean at all; you can even see your fingerprints in the exact spot where the print is not adhering.
RE: My printer seems to be slowly dying
Here are a couple of pictures of the hotend. I tripled checked that it does not go any higher up when I push it in. About the comment about washing the sheet, I just did and started another print, even though I think low adhesion is not the root cause. It just makes the problem more apparent (when I use a smooth PEI sheet, pieces take longer to break off from the bed because adhesion is strong enough that parts get scratched up instead of detached. If I use the textured PEI sheet, they break off faster).
But then again, I've been wrong before. I gave that smooth PEI sheet a deep wash with dish soap and warm water, followed by spraying it with alcohol and carefully drying it. I'll update as soon as I get some results.
Again, thanks to everybody for all the suggestions!
RE: My printer seems to be slowly dying
Since the CORE One, Prusa recommends lubricating the Z-axis. Mine made an unpleasant vibrating noise when it moved, but that completely disappeared after pouring a drop of oil on the threads.
Perhaps your Z-axis is not moving freely and the print is being crushed.