Issues appearing suddenly on a prusa Mk4s HF nozzle 0.4  

RE:

Posted by: @madaeon

I have a Prusa MK4 upgraded to Mk4S some months ago. Always worked flawless.

-Autotest: self heating fails when going up to 290°C, stops about 180°C. If I skip this and print anyway, prints are fine.

This is something I had to face on my MK4 to MK4S upgrade as well, and if you followed the instructions as Prusa provided the fix for this may come off as counterintuitive:

If you install the silicone sock on your printer before running the Heater test, it will always fail. From what I can tell, it's because the printer is testing the heater and the part cooling fan together to make sure that the climb to the set temperature is consistent, and with the silicone sock installed the fan isn't able to properly control the heat that the cartridge is generating.

To fix this, you must take off the sock before the Heater test, then after the test passes you MUST re-install it. 

After you go through the tests and try to print something, from my experience I always ran into issues with the printer giving a Hotend Thermal Runaway error after a few minutes of printing. I eventually found out that the cooling on the MK4S works a little too well and it sends the hotend down almost 10 degrees Celsius once the part cooling fan goes full blast and the cartridge can't recover quick enough.

In short, you'll need to keep these things in mind:

• Heater test doesn't like the silicone sock
• You can't print anything without the silicone sock installed
• (bonus) Either reduce your temps or reduce the max fan speed if you're having solid strings on your model.

RE: Issues appearing suddenly on a prusa Mk4s HF nozzle 0.4

Thanks for the tip. I will try it.

However, for the price of the printer, you would expect an official solution, this kind of workarounds would be justified on a cheap Chinese printer , in my opinion.

Do you know where I can find solutions for the layer shift and "Gcode is not fully compatible error"? I mean official support? I have a tough time finding it? Maybe it is just me...

RE: Issues appearing suddenly on a prusa Mk4s HF nozzle 0.4

I also have tested and have same autotest issue without the silione cap

RE: Issues appearing suddenly on a prusa Mk4s HF nozzle 0.4

-layer shift during prints: sometimes in the X, sometimes in Y, once both; after firmware update, so far, seems to not happen again. Belt test is ok;

If upgrading the firmware fixed the issue for you and the Belt Tuner shows that it's set correctly, I wouldn't worry about it for now. If it happens again, make sure to check the belt tuning again and also check the grub screws are fully tightened down, if it's loose even by 1/8th of a turn it can cause issues.

-Printer now says each time "Gcode is not fully compatible error" even if Prusa slicer is set to "original prusa Mk4s HF nozzle 0.4", send prints wireless works, and on the machine, it is also set as Mk4s with high flow nozzle.

I don't know what size nozzle you had installed before the conversion, so I would check that the printer firmware shows that a 0.4 HF nozzle is installed before your next print.

I also have tested and have same autotest issue without the silione cap

If you're still having the Heater test fail without the silicone sock, try setting the Temperature to anything above 170 C and watch the reported temps on the printer itself. It sounds like there may be one of three issues:

• Most likely, the thermistor is bad. If so, the reported temperature will fluctuate when it shouldn't, or it won't report a temp at all.
• The heater cartridge is bad. This may be a bit trickier to test, as it may also appear like the thermistor is not reporting anything. I don't really know of a safe way to determine the difference, other than using a multimeter if you have one available.
• Lastly, it's possible that the LoveSense board, the Buddy board, or the wiring anywhere in between may be having issues. Best way to test this is using a multimeter between all the parts to track down the problem.

RE: Issues appearing suddenly on a prusa Mk4s HF nozzle 0.4

Posted by: @tnxgam3rx

 

Posted by: @madaeon

I have a Prusa MK4 upgraded to Mk4S some months ago. Always worked flawless.

-Autotest: self heating fails when going up to 290°C, stops about 180°C. If I skip this and print anyway, prints are fine.

This is something I had to face on my MK4 to MK4S upgrade as well, and if you followed the instructions as Prusa provided the fix for this may come off as counterintuitive:

If you install the silicone sock on your printer before running the Heater test, it will always fail. From what I can tell, it's because the printer is testing the heater and the part cooling fan together to make sure that the climb to the set temperature is consistent, and with the silicone sock installed the fan isn't able to properly control the heat that the cartridge is generating.

To fix this, you must take off the sock before the Heater test, then after the test passes you MUST re-install it. 

After you go through the tests and try to print something, from my experience I always ran into issues with the printer giving a Hotend Thermal Runaway error after a few minutes of printing. I eventually found out that the cooling on the MK4S works a little too well and it sends the hotend down almost 10 degrees Celsius once the part cooling fan goes full blast and the cartridge can't recover quick enough.

In short, you'll need to keep these things in mind:

• Heater test doesn't like the silicone sock
• You can't print anything without the silicone sock installed
• (bonus) Either reduce your temps or reduce the max fan speed if you're having solid strings on your model.

Odd.  I have never used the sock on my MK4S and have never had an issue.