Moving MMU2S outside enclosure and PTFE to Extruder Tube Length
 
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Moving MMU2S outside enclosure and PTFE to Extruder Tube Length  

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NarlyB
(@narlyb)
Active Member
Moving MMU2S outside enclosure and PTFE to Extruder Tube Length

I have been trying to find information on having a longer PTFE to Extruder tube without success.

I asked support online and the answer was a simple, "Don't change it"

Has anyone successfully made this modification or know of articles that address this?

 

I have tested a longer tube and find that it loads fast for about 30mm beyond the normal PTFE tube length and then creeps its way to the extruder.

Posted : 25/06/2020 1:59 am
gnat
 gnat
(@gnat)
Noble Member
RE: Moving MMU2S outside enclosure and PTFE to Extruder Tube Length

I tested a full meter between the MMU and extruder back with 1.0.3 or 1.0.4 and it "worked" as you experienced. I looked at the MMU firmware code and it is supposed to do that for the first change for each tool and then store the distance it detected for later changes. My experience, however, is that it redoes the search process for every tool change (so my test that PS estimated at 13 minutes actually took around 40 or so).

I seem to recall that in 1.0.5 or 1.0.6 that the release notes said they were going back to the preset expected length with only a small amount of searching.

 

If I ever get around to setting up an enclosure I intend to move the MMU so it is in a humidity controlled area with my spools. I expect I'll need to modify the firmware to work efficiently.

MMU tips and troubleshooting
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Posted : 27/06/2020 12:51 am
Bikebandit
(@bikebandit)
Active Member
RE: Moving MMU2S outside enclosure and PTFE to Extruder Tube Length

@gnat

Hey gnat,
Do you know how to modify the MMU firmware? I have move the control board outside my enclouse to thermal problems, however, I now have the issue that my custom cable extenders have increased the wire resistance and the homing is not sensitive enough thus I need update the stallguard values. Thanks so much for your time.
Kyle

Posted : 22/08/2020 5:23 am
gnat
 gnat
(@gnat)
Noble Member
RE: Moving MMU2S outside enclosure and PTFE to Extruder Tube Length
Posted by: @email-1

@gnat

Hey gnat,
Do you know how to modify the MMU firmware? I have move the control board outside my enclouse to thermal problems, however, I now have the issue that my custom cable extenders have increased the wire resistance and the homing is not sensitive enough thus I need update the stallguard values. Thanks so much for your time.
Kyle

I haven't modified it yet, just poked around to answer questions and better understand what is happening. The source can be found here and there are build instructions in the README.

The build instructions look straight forward to me, but I've been coding for a living for a long time.

MMU tips and troubleshooting
Stop SL1 tank leaks with a simple o-ring...
Posted : 26/08/2020 3:13 pm
vintagepc
(@vintagepc)
RE: Moving MMU2S outside enclosure and PTFE to Extruder Tube Length

you need to look at the old MK3 MMU2 guidance and do the section on calibrating the bowden tube length. Then you can have it load fast for the entire length of tube. 

 

Posted : 26/08/2020 5:58 pm
MileHigh3Der
(@milehigh3der)
Estimable Member
RE: Moving MMU2S outside enclosure and PTFE to Extruder Tube Length

I thought the mmu2s and new sensorgot rid of the need to calibrate the tube length?

Posted : 10/12/2020 7:31 pm
NarlyB
(@narlyb)
Active Member
Topic starter answered:
RE: Moving MMU2S outside enclosure and PTFE to Extruder Tube Length

@milehigh The distance is still important.  if you make it much longer, it will load fast and thenslow down and creep the fillament to the extruder.

I finally decided to just move the electeronics outside my enclosure.  I extended the cables and added connectors to make my life easy.  No more heat on the electronics when I heat up to 60C.  I did remount my mechanics off the frame to a 3030 extrusion bar inside the enclosure.  I did not have to modify the tube length.

Posted : 11/12/2020 2:39 am
vintagepc
(@vintagepc)
RE: Moving MMU2S outside enclosure and PTFE to Extruder Tube Length

Correct, it is not required anymore with the 3S for *stock* setups, but the length calibration still serves the purpose to define the distance the MMU2 will "fast" feed the filament to the extruder. 

Posted : 11/12/2020 3:33 pm
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