Prusa MK4 & Octoprint  

RE: Prusa MK4 & Octoprint

Posted by: @yeungster

I've noticed a difference in behaviour recently with manual filament colour changes mid-print but I'm not sure whether this was introduced with the latest software updates for the MK4 or whether this is unique to Octoprint (not had a chance to test yet).

Previously my manual colour changes worked flawlessly when printing from USB stick. Remove old filament, load new, purge, confirm colour is correct, resume printing from place it left off - all good.

What I'm experiencing now is exactly the same as above, but immediately after confirming the colour is correct (after purging), the nozzle zooms to the place it left off, but it also purges out filament as it starts printing. Thankfully I've managed to save it the last couple of times by swiping at the extra poop but is this unique behaviour to Octoprint/printing via serial or has this crept in with the latest Prusa software updates?

Is there any way around this? I followed the official Prusa Octoprint instructions for adding custom g-code elements, so no idea where to look next.

Thanks
Pete

Just tried the filament change using Prusalink and it does the same extra purge as, on location, just as its resuming.

I'm convinced it never behaved this way preciously. Was this intentional?

RE:

The extra purge has been an issue for as long as I can remember (Prusa Mk1 era) (When we were using Slic3r as the standard slicer(Predecessor to Prusa Slicer))

What I do, 
is go through the normal steps of filament change until the new filament purges the old filament, 
At this stage I DO NOT PULL THE WASTE OFF. 
instead, I Hold on to the waste with pliers or my fingers. 
and instruct the printer to continue. 
As the nozzle moves back to the model, the annoying extra purge is extruded, but it stays connected to the waste that you are holding, ad pulls off the nozzle. 

regards Joan

RE: Prusa MK4 & Octoprint

Thanks Joan. Great suggestion. I'll do that.

I must be going crazy 🤪. I would have put money on it. Good job i didn't 😆.

• Thanks

RE: Prusa MK4 & Octoprint

If I had a pound for every time I have answered the extra purge messages, I would be a more wealthy woman! 
Lol

https://marlinfw.org/docs/gcode/M600.html (M600 code description)

Your next question, is likely to be, 
"Why does the Printer go back to the last position, it printed, after the colour change, and leave a 'Beauty Spot' there? before continuing with the print...)  

answer, whoever wrote the Colourchange script, didn't address that issue... 

there is an additional parameter in the M600 Action command structure  
M600 N    

See Information 
https://reprap.org/wiki/G-code#M600:_Filament_change_pause

the 'N' parameter is supposed to stop the printer returning to the previous position, but it does not seem to be implemented in Prusa Firmware. 

When I am using M600, for colourchange by layer height, I do the colour change one layer higher than normal, this results in the last print position being beneath the colour change start position, and therefor not being visible, after the colourchange. 

If this is not possible, I put a piece of paper over the print whilst the nozzle is in the colourchange position, and when the printer goes back to the last position, it dabs on the paper, and I whip the paper out taking the 'beauty spot' with it
Not ideal, but it's a functional option. 

regards Joan

RE: Prusa MK4 & Octoprint

Posted by: @kevman

does the filament runout sensor work with Octoprint and the MK4 ?

OctoPrint have several plugins for filament runout sensor. I have been using OctoPrint for 3 years on an Ender 5 plus without bothering with the sensor but I did connect the original Ender sensor to the OctoPrint PI today and it seems to work fine (did not have time to do a real test during printing, I'll do that tomorrow). Only needed to make a cable with the correct plug in the end... Using "Filament Sensor simplified" plugin.

The Ender 5 use a micro switch but I believe the hall sensor in MK4 should be usable directly in the RPi.

RE: Prusa MK4 & Octoprint

With the firmware versions in the beginning the printer just kept on with the motions without filament on filament runout when using OctoPrint. But since firmware version 5.1.0 the MK4 pauses and beeps, you have to change the filament via the screen on the printer and the print continues. You should read this posting:
https://forum.prusa3d.com/forum/english-forum-original-prusa-i3-mk4-general-discussion-announcements-and-releases/5-1-0-firmware-for-original-prusa-mk4-is-out/
And search in the post for the heading "Improved Octoprint support". Follow the steps there to enter some G-Code scripts into the configuration of OctoPrint to make the filament runout sensor work with OctoPrint.

RE: Prusa MK4 & Octoprint

I blindly ordered my MK4 without thinking much about OctoPrint, because I thought it would be 1:1 the same experience (or even better).

When I connected it and saw the OctoPrint icon on the screen I cheered up and was happy. After some time I realized that it's still in progress and incomplete, no info on the screen is such a bummer, or the missing USB drive reading (I printed the MMU3 parts and didn't want to mess with OctoPrint yet).

Great to see that at least Prusa acknowledge and wants to further support / improve integration with OctoPrint, but honestly I was expecting this from the start up (like many others). I keep my fingers crossed that this year more improvements will arrive. <3

And MMU3 support is another level. 😀

RE: Prusa MK4 & Octoprint

Hi

Did any one of you try to print big file ( >20Mbyte) using the OctoPrint and it work ?

all my tries was stop after few hour with  serial exception error  you can see the  full story in  a post that  i wrote and did not get any

response from this forum or the OP forum

MK4  Framework   6.1.3

RE:

Posted by: @sonra

Hi

Did any one of you try to print big file ( >20Mbyte) using the OctoPrint and it work ?

all my tries was stop after few hour with  serial exception error  you can see the  full story in  a post that  i wrote and did not get any

response from this forum or the OP forum

MK4  Framework   6.1.3

 

I doubt I have printed a gcode file that large with Octoprint, but file size should not matter -- commands are sent to the printer one-by-one.  I have certainly printed 12+ hours-long prints, whereas the last failure was at 3hours 15 minutes. That's a relatively short time, and I routinely have prints longer that that which complete without any issues.

I found your logs on the Octoprint forum and reviewed them.  From the logs, the issue does not look like an Octoprint problem or Rpi power problem.  The error you are getting indicates a communication loss (i.e., either the printer stopped responding to Octoprint, or communication between the two was lost). 

It *could* be a Prusa firmware fault, but I have not experienced this or seen anyone else report it.  What was the state of the MK4 screen after this happened?  Did it still show "serial printing"?  Was it responsive?  Was it still heating the bed and toolhead?  There have been (rare) overheating problems with the buddy board; particularly with long prints in an enclosure, a few folks have had it "red-screen" and spontaneously reboot.  

It *could* be a bad cable, poorly shielded cable, or loose cable connection. An easy test would be to replace the cable and try again.  

It *could* be some other process on the Pi interfering with comms.  Do you have anything other than Octoprint running on the Pi?

RE: Prusa MK4 & Octoprint

Sames...

-rw-r--r-- 1 octoprint-mk4 octoprint-mk4 67M May 26  2024 'SStopfmitloechern v5_0.4n_0.2mm_PETG_MK4ISMMU3_13h30m.gcode'

Largest file I've successfully printed (that's still lying around on the Octoprint instance) -- Its a flower pot.

(Dedicated PI4, USB attached SSD, LACK enclosure, but its generally left slightly open for heat reasons - The PI/SSD are both external to the MK4).

In the middle of a 6 hour print (but its only 12Mb of gcode).

I'd agree w/ Scott, and lean toward your PI environment, and/or cable... 

RE: Prusa MK4 & Octoprint

Do you by any chance have the USB thumb drive inserted in your MK4? It is just a suspicion of mine, but the USB port on the display and the USB port on the buddy port that is used to connect to OctoPrint perhaps conflict with each other. I only connect my USB drive to the MK4 for firmware updates and have it not inserted when I print with OctoPrint. The drive is not needed at all when printing via OctoPrint. I vaguely remember seeing that error some time in the early days with my MK4, but I am not sure if it was that same error.

I would suggest removing the USB drive from the MK4 and give it another try if it works that way for you.

About the file size I use with OctoPrint, see screenshot from today. I also have a similarly sized print currently running on my MK3S+ and I have printed files sized over 90 MB in the past with no problem.

RE: Prusa MK4 & Octoprint

Hi

Thanks for replay

No i do connect the DOK to the display port (as you only when update OS of  the printer

1)Can you  check what ver of OctoPrint you use?

2)   Can you try to  print  large file on your MK4 ?(may be printer model   problem ) 

3)  if you try on your MK4 and it work can you check what software framework is installed on the MK4printer 

I don' t know if  you read me original  topic in the forum but the problem happens  after few hours of printing with no problem

and i can print small /medium size files

Hope no big problem for you  

Regards  Doron

0

3) 

RE: Prusa MK4 & Octoprint

This is the software string from the bottom of the OctoPrint screen: OctoPrint 1.10.3Python 3.9.2OctoPi* 1.0.0cam (build 2024.06.18.101629)
My MK4 is running on firmware version 6.1.3.

My printer is currently printing, so I cannot start another print right now. But I have checked what the biggest files were I printed on it since the last upgrade of the OctoPi image. All ran without a problem:

RE: Prusa MK4 & Octoprint

Can you also check the "resend ratio" (Resendverhältnis in my screenshot) on your printer when it is printing, this value should be 0 or very close to 0. Did you try to use another USB-C cable between the Pi and the printer? One with good shielding?

RE: Prusa MK4 & Octoprint

My installation is
  Octoprint 1.10.3
  Python 3.11.2
  Octopi 1.1.0  on Pi5

Printer is MK4 upgraded to MK4S, firmware 6.1.3.

Unless you're running something else on the Pi that might reset ports, my best guess is poor cable or connection.

Posted by: @sonra

Hi

Thanks for replay

 

No i do connect the DOK to the display port (as you only when update OS of  the printer

1)Can you  check what ver of OctoPrint you use?

2)   Can you try to  print  large file on your MK4 ?(may be printer model   problem ) 

3)  if you try on your MK4 and it work can you check what software framework is installed on the MK4printer 

I don' t know if  you read me original  topic in the forum but the problem happens  after few hours of printing with no problem

and i can print small /medium size files

Hope no big problem for you  

Regards  Doron

 

 

 

 

 

0

3) 

RE: Prusa MK4 & Octoprint

Thanks for help

will try other cable

RE: Prusa MK4 & Octoprint

Hi

Yes It was  a USB cable  problem 

Thanks for help Doron