Bed cools down when MMU2S requires attention
A week in and have not had one successful print yet from my MK3s/MMU2S.
I think I'm starting to get to grips with tuning it it now but one issue I'm having is that if I get an error when the printer is unattended for any length of time (During the night for example) the heat bed cools down. This never was never an issue before I had the MMU2S attached. If the filament ran out during the night it would sit there waiting all day without issue. I was using Mk3S firmware 3.7.0.
Since fitting the MMU2S and using the MK3/S MMU2S firmware 3.7.1 If I have a load error the bed cools and the partially printed part releases from the bed and ruins any chance of resuming the print.
Also had a random thing last night where as soon as the print would start after bed level it would just reboot. tried various gcodes with the same results. I disabled the RPI and it seemed to stop but no idea as it wasn't doing this before last night and the RPI has been enabled all week without issue.
I have factory reset the MMU.
My next step was to factory reset the MK3 and re-flash the firmware but before I did this i need to know if anyone else is having similar issues.
Thanks
Best Answer by gnat:
For the reboot issue, I ran into that when I tried to print a plain MK3S sliced file with the MMU attached.
For the bed cooling, I'm still on 3.7.0/1.0.5 and that doesn't happen for me. Just the nozzle cools.
RE: Bed cools down when MMU2S requires attention
As fas as I read, the Printer basically resets when the RPI connects. Starting a print while the printer is reconnecting to the MMU will most likely lead to strange behaviour. I think by waiting a bit before starting the first print-job you can avoid this.
I don't know about the bed temperature, but the other side of the coin is that I've had a print finish with an unload failure and found the nozzle still hot. For safety I'd also like to know more about what is actually going on regarding temperature when there's a failure (timeouts/watchdogs?)...
My prefered behaviour would be:
Bed: On (for a long time)
Nozzle: Off (soon) (but better stay above MinTemp)
RE: Bed cools down when MMU2S requires attention
Agreed. Nozzle off / bed on. Which is exactly what happens with a filament run out.
As far as the RPI the Pi Zero is so slow I've been using the SD card so I'll probably take it out completely. Just thought it was strange that I'd not had this issue before last night. Its not like I'm doing anything different.
Power on, start print, everything heats up. Mesh bed level, moves to home, loads filament to nozzle. Then power cycles like the reset button has been pressed.
RE: Bed cools down when MMU2S requires attention
I have seen the power cycle problem exactly as you described it. MK2.5S, MMU2S, RPI 3B, Octoprint. and current firmware. I don't know exactly what fixed it since I was also doing various resets. But, I found I was loading a print for a 4mm nozzle when I had a 6mm in it. Obviously, the printer doesn't know what nozzle is in, although that would be nice. It did start working when I loaded the correct file.
David
RE: Bed cools down when MMU2S requires attention
For the reboot issue, I ran into that when I tried to print a plain MK3S sliced file with the MMU attached.
For the bed cooling, I'm still on 3.7.0/1.0.5 and that doesn't happen for me. Just the nozzle cools.
RE: Bed cools down when MMU2S requires attention
I thing I might go back to 3.7.0 and see if I have more success.
RE: Bed cools down when MMU2S requires attention
3.7.1 came out just before I got my MMU working, but I got it working before I upgraded. I forget what they were, but I saw some complaint of 3.7.1 having some issues so I've so far opted to "not fix what ain't broke" 😉 😆
I keep forgetting to turn off the option in the Slicer that makes the printer nag me every time I start a print though...
RE: Bed cools down when MMU2S requires attention
I was of the same mind before the MMU came. My MK3s couldn't have been more solid and only updated it due to attaching the MMU presuming that the firmware was different. I'm guessing then that the firmware isn't specific between MK3S or Mk3S/MMu2S. It's just that you get the MMU 1.0.5 firmware in the one download and not in the other.
RE: Bed cools down when MMU2S requires attention
I think I remember specifically what the problem was. I had accidentally turned off the printer setting that specifies "Single Extruder Multi Material".
David
RE: Bed cools down when MMU2S requires attention
Reverted to 3.7.0. Tuning temps and settings for better tip points but seems to be printing very well. Best it’s been going since I received my MMU. Four hours now and only needed attention once and that was due to a stringy tip which I think is because of some uber cheap PLA. Unfortunately it’s the only white I have at the moment but have some fresh supplies coming tomorrow
Not sure about the bed heater as I’ve been babysitting it. I’ll have a print running overnight so I guess we will see in the morning. That is providing I get a load error through the night which I’m sure is highly likely.
RE: Bed cools down when MMU2S requires attention
OK so this morning the print had paused due to a load error (stringy tip). Nozzle was cool but bed was still hot and the print resumed without issue.
Looks like 3.7.0 did the trick. Thanks for your input everyone. Much appreciated.