Survey for happy MMU2 users only  

RE: Survey for happy MMU2 users only

Posted by: Antimix

A) How many successful MMU2 prints you have done ? (1..10, 10..50, 50...100, over 100)

Between 10 and 50. Probably 20-30.

B) What is the average duration of your MMU2 print ?

Around 8 hours, with the longest being five days.

C) What is the average of manual intervention during your MMU2 print ?

About one intervention every 200 material changes.

D) Assuming 100% all your MMU2 print, what is the percentage of:
- PLA Filament % ?
- ABS Filament % ?
- PET/PETG Filament % ?
- Other HT materials % ?
- Flex % ?

Since upgrading to the MMU2S, I'm about 50% PETG, 25% PLA, and 25% ABS. I have not yet tried flex with the MMU2S, but I did a fair amount of flex (maybe 15%) with the MMU2.

E) Do you have applied substantial modification to the original MK3/or MMU2 project (e.g. tube change, MMU2 parts improvements...) ? Y/N (if yes, what)

I'm purely stock MMU2S. I haven't even tweaked any of the filament settings (but if I did, it would probably improve my performance).

RE: Survey for happy MMU2 users only

I assume you are only interested in multi-color/multi-material prints and not single material prints.

So:

A) 10..50

B) 8h

C) 1 in about 200 changes

D) 90% PLA and 10% PVA

E) Y - Replaced the orange PTFE with a 2mm one

RE: Survey for happy MMU2 users only

A) Over 100 successful prints
B) In avarage 12h prints. More important are maybe the tool changes. In my case ~400 on average
C) 0-10 interventions. It highly depends on the filament and object I'm printing. Everything I have on filament in stock is also being used for MM prints. So not so perfect filament tips are just a side effect of this. Small objects with many filament changes are also tend to ask for attention.
D) PLA/HTPLA 90%, PETG 10%
E) No modifications. Initial MK3+MMU2 and switched to MM3s+MMU2s, always stock. Filament buffer is the only thing I've replaced first of all because of the placement and second because of the function.

F) Success rate of the prints over 90%

RE: Survey for happy MMU2 users only

This is all after my tweaking...

A: Over 50 successful prints (about 80 objects).  Thousands of tool changes, especially the early stress tests deliberately cycling materials. I have had no outright failures provided I get past Layer 1 (generally not any MMU specific issues here)

B: Around 8 hours or so. I generally add/remove objects from the bed to be around this estimate. I don't like printing overnight unless I'm 99% confident of successful completion, and I'm not there yet.

C: About 10. Depends on my materials. Basic fresh PLA has completed without intervention many times. I have a transparent (8 year old) brittle PLA which likes to cause problems.  I believe if tuning the nozzle temperature during a print retained the setting per-filament rather than global, I could fix this issue. The other problem that I seem to eventually hit is stringing eventually causing a failure. Ambient temperature seems to play a factor here and is hard to deal with. When the selector wants to fold over a piece of filament rather than cut it, sad times are ahead for me as the selector will jam and I need to remove the motor.

D: 80% PLA 20% PETG

E: 1: Capricorn 1.9ID in the hot end (had no spare tube, the one I got with the kit was widened during my early troubles and needed replacing)

E: 2: Retracting spool holders as i: the buffer is an extremely poor ergonomic design for loading filament. When I had issues early on and was pulling filament out the MMU a lot, this was incredibly annoying and ii: allows me more flexibility with where to place the spools.

RE: Survey for happy MMU2 users only

Posted by: Antimix

This is intended only for people that after several fine tuning and tests were finally able to use their MMU2 in a reliable way.

A) How many successful MMU2 prints you have done ? (1..10, 10..50, 50...100, over 100)

B) What is the average duration of your MMU2 print ?

C) What is the average of manual intervention during your MMU2 print ?

D) Assuming 100% all your MMU2 print, what is the percentage of:
- PLA Filament % ?
- ABS Filament % ?
- PET/PETG Filament % ?
- Other HT materials % ?
- Flex % ?

E) Do you have applied substantial modification to the original MK3/or MMU2 project (e.g. tube change, MMU2 parts improvements...) ? Y/N (if yes, what)

 

A: about 8 I think

B: around 10 hours

C: Currently about two manual interventions but I've been slowly dialing in some assembly issues. I didn't have my extruder gear tighted to the flat spot on the axle so it would loosen over time. A small over site that has lead to big improvements after fixing.

D: I have only printed in PLA so far

E: I have not done any mods. Only thing I've looked in to is the auto re-wind spools but have yet to impliment.

RE: Survey for happy MMU2 users only

A: I have about 20-30, but that came after a LONG time of troubleshooting, and probably 15 of those 30 had frequent intervention on my behalf.

B. ~7-8 hours. I don't bother with mega prints like those 1-2 day ones because the chance of failure seems kinda high, even with my setup.

C. Until June and July of this year, it was about 4-5 interventions each. Sometimes it took as many as 20. After June, though, I've had from 0-2 interventions and that is good news!

D. 99.9% PLA, and 1 PETG print that was a multicolor modification.

E. Yes, definitely. I don't know anyone who hasn't modified their MMU2 and had success (except maybe Prusa). I won't detail it all here but I mainly have a pass-through coupling instead of the normal Festo on the extruder side of the long tube (that's the only major change), a widened selector filament tunnel/hole, and revamped filament settings. Here's a link I did to that if you're interested: https://forum.prusa3d.com/forum/original-prusa-i3-mmu2s-mmu2-general-discussion-announcements-and-releases/successful-mmu2s-modifications-re-upload/

RE: Survey for happy MMU2 users only

A) About 30 prints thus far after initial tweaking which primarily consisted of selector door spring tightness and selector filament sensor.

B) Mostly in the 2-4 hours range.

C) Most prints completing with no interventions (of 30 probably 25 or so were no intervention). The issues have primarily been filament driven (in particular one Solutech Red PLA filament which mayhaps was left out too long...or just a problem filament).  Binding in filament buffer.  Not loading correctly.  I initially had problems with filament not fully retracting in the selector and then bending over but that was solved with sensor and spring adjustments.

D) I have only printed in PLA for this machine.

E) No modifications at all except I built the Lack enclosure.  I would prefer autowind spools if I can find one that works with the Lack setup.  Else I will have to create one myself when I have time.

RE: Survey for happy MMU2 users only

A) 30-50

B) 12-15 hrs

C) After 10 prints or so, I figured out what the pain points/likely problem spots are and I go 10-15 long prints easily without any issues at this point. I think that that number will increase as I maintain the proper settings/adjustments

D) PLA Filament % - ?      50%
- ABS Filament % ?           None
- PET/PETG Filament % ?  50%
- Other HT materials % ? None yet, but I'll be moving to soluble supports, nylon and other more abrasive/durable filaments
- Flex % ? None yet

E) Stock 100%

I'm extremely happy with this unit now that I've got past the learning curve. I'll admit, getting the first few prints done were a bit painful and there was some frustration with the filament selector and print head. I could see many having a VERY difficult time getting things right.

But once it's figured out and working reliably it is a beautiful thing. 🙂

RE: Survey for happy MMU2 users only

A) How many successful MMU2 prints you have done ? (1..10, 10..50, 50...100, over 100)  Over 200 after upgrade to MMU2s

B) What is the average duration of your MMU2 print ?  16 hours

C) What is the average of manual intervention during your MMU2 print ?    I am getting 5 to 10 prints without any intervention and then will have a problem print that requires 4 or more to finish the print.   The good news is that since the upgrade to MK3S/MMU2S I have had only 2 prints that were not recoverable.

D) Assuming 100% all your MMU2 print, what is the percentage of:
- PLA Filament % ? 45
- ABS Filament % ? 0
- PET/PETG Filament % ? 50
- Other HT materials % ? 0
- Flex % ? 5

E) Do you have applied substantial modification to the original MK3/or MMU2 project (e.g. tube change, MMU2 parts improvements...) ? Y/N (if yes, what)   Completely stock MK3S / MMU2 upgraded from MK3 / MMU2.   It is really important to have good profiles for the filaments that you are using.   This means taking the time and filament to do the tests to get profiles that work for your filament and printer.

RE: Survey for happy MMU2 users only

Posted by: @antimix

This is intended only for people that after several fine tuning and tests were finally able to use their MMU2 in a reliable way.

A) How many successful MMU2 prints you have done ? (1..10, 10..50, 50...100, over 100)

Haven't really kept track, but I'd say around 20 after getting the system sorted and happy.

B) What is the average duration of your MMU2 print ?

Varies wildly from 30 minute prints to a 100 hour print.

C) What is the average of manual intervention during your MMU2 print ?

If I haven't touched anything (e.g. changing nozzles, cold pulls, etc..) after getting dialed in, 0. I did a 100 hour print with 1204 tool changes (at least one tool change every layer after the first 3mm) with no manual intervention. The prior attempt at that print (failed due to design issues rather than MMU problems) ran for about 46 hours and had 3 change failures due to tip stringing fouling the FINDA. This was due to the tension on the extruder idler not being set right after doing cold pulls and a nozzle change. After the final adjustment to the door I got 16 hours out of that print before I killed it with no further issues.

D) Assuming 100% all your MMU2 print, what is the percentage of:
- PLA Filament % ?

My multi-tool prints have been 100% PLA so far.

E) Do you have applied substantial modification to the original MK3/or MMU2 project (e.g. tube change, MMU2 parts improvements...) ? Y/N (if yes, what)

Yes

- Spools are held above the printer on a 2020 frame. The spools just have a "pin" through their hole. No bearings or bushings are used.
- The Prusa buffer is hung off the back of the spool frame in a vertical orientation.
- I added the tabs to the buffer that allow for using PTFE pass through fittings and also moving all inputs and exits to the same side.
- Replaced all PTFE with Capricorn XS (apparently caught it at an incredible sale price!)
- All curvature of the PTFE tubes is kept to a minimum and as smooth/gentle as possible
- Added the MMU mod to use PTFE pass through fittings on the input side of the MMU
- Did the LED mod to the IR sensor

RE: Survey for happy MMU2 users only

Posted by: @antimix

This is intended only for people that after several fine tuning and tests were finally able to use their MMU2 in a reliable way.

A) How many successful MMU2 prints you have done ? (1..10, 10..50, 50...100, over 100)

B) What is the average duration of your MMU2 print ?

C) What is the average of manual intervention during your MMU2 print ?

D) Assuming 100% all your MMU2 print, what is the percentage of:
- PLA Filament % ?
- ABS Filament % ?
- PET/PETG Filament % ?
- Other HT materials % ?
- Flex % ?

E) Do you have applied substantial modification to the original MK3/or MMU2 project (e.g. tube change, MMU2 parts improvements...) ? Y/N (if yes, what)

 

A: so far, dozens of prints.

B: multicolor prints have mostly been 5-15 hours.  Most recent was 50 hours.

C: 1 per 500 changes.

D: 90% PLA.  10% PETG.  (I am not mixing them yet.)

E:

i) passthrough adapter: https://www.thingiverse.com/thing:3233579

ii) I don't use the filament buffer.  Instead I have a system where the tubes are weighted and lower themselves on retraction.  (Spools are above, on prusa-supplied spool rollers).

iii) I added two of these heat sinks to the extruder, one on the left and one on top.  (they are self-adhesive):

https://www.digikey.com/product-detail/en/cts-thermal-management-products/BDN14-3CB-A01/294-1101-ND/272739

iv) As a general rule, I don't change the default filament settings.  Instead when I encounter problems, I am usually try to locate a problem with the physical setup.  I worry that the temptation to change filament settings as soon as there are problems introduces extra variables which are sometimes unnecessary.  The physical setup already includes several such variables which need to be examined first.

RE: Survey for happy MMU2 users only

Posted by: @wpegden

Posted by: @antimix

This is intended only for people that after several fine tuning and tests were finally able to use their MMU2 in a reliable way.

A) How many successful MMU2 prints you have done ? (1..10, 10..50, 50...100, over 100)

B) What is the average duration of your MMU2 print ?

C) What is the average of manual intervention during your MMU2 print ?

D) Assuming 100% all your MMU2 print, what is the percentage of:
- PLA Filament % ?
- ABS Filament % ?
- PET/PETG Filament % ?
- Other HT materials % ?
- Flex % ?

E) Do you have applied substantial modification to the original MK3/or MMU2 project (e.g. tube change, MMU2 parts improvements...) ? Y/N (if yes, what)

 

A: so far, dozens of prints.

B: multicolor prints have mostly been 5-15 hours.  Most recent was 50 hours.

C: 1 per 500 changes.

D: 90% PLA.  10% PETG.  (I am not mixing them yet.)

E:

i) passthrough adapter: https://www.thingiverse.com/thing:3233579

ii) I don't use the filament buffer.  Instead I have a system where the tubes are weighted and lower themselves on retraction.  (Spools are above, on prusa-supplied spool rollers).

iii) I added two of these heat sinks to the extruder, one on the left and one on top.  (they are self-adhesive):

https://www.digikey.com/product-detail/en/cts-thermal-management-products/BDN14-3CB-A01/294-1101-ND/272739

iv) As a general rule, I don't change the default filament settings.  Instead when I encounter problems, I am usually try to locate a problem with the physical setup.  I worry that the temptation to change filament settings as soon as there are problems introduces extra variables which are sometimes unnecessary.  The physical setup already includes several such variables which need to be examined first.

Also, one more thing.  I did go through some phases where I was having trouble with loading / unloading.   But I have never had the mmu2s cause a print failure!   As I understand it, this is thanks to the big advantage of the new IR sensor setup over the previous mmu2 system.

RE: Survey for happy MMU2 users only

A) How many successful MMU2 prints you have done ? (1..10, 10..50, 50...100, over 100)

>>> Approaching 100:  ~20 multi color prints (5 colors), many single color prints, either printing the same object in several colors, or swapping between PETG and ABS.  A lot of test prints/filament changes in testing my Tower Print Buffer.<<<

B) What is the average duration of your MMU2 print ?

>>> 8 Hours.  Shortest is just under 2 hours, longest is multiple days (no filament swap on the > 12 hour prints yet).

C) What is the average of manual intervention during your MMU2 print ?

>>> Currently near zero for MMU2 related issues.  Most interventions are first layer (bed not clean w/PETG), or Flex material feeding problems.  Early prints had major MMU2 issues: Re-printed the Idler as it was a poor fit in the housing; redesigned the filament buffer as spool changes were too painful and left my print room a mess with spools scattered around the printer. <<<

D) Assuming 100% all your MMU2 print, what is the percentage of:
- PLA Filament % ?
- ABS Filament % ?
- PET/PETG Filament % ?
- Other HT materials % ?
- Flex % ?

>>> 75% PETG, 20% ABS, 4% PLA, 1% Flex (Still working on Flex.   It does not feed through the MMU2S to the nozzle reliably so I am still bypassing the MMU2S unit and direct feeding Flex for now). <<<

E) Do you have applied substantial modification to the original MK3/or MMU2 project (e.g. tube change, MMU2 parts improvements...) ? Y/N (if yes, what)

>>> Re-printed the idler as it did not fit well.   Tweaked cooling delays to minimize stringing/stretching of the retracting filament.  Redesigned the print buffer to a tower and spool storage over the printer to save space, and improve filament feeding/spool changing.  Upcoming changes:  1) Print head filament sensor mount redesign - this is working well now but has little margin for error. 2)  Improve the filament insertion path into the MMU2S Idler area - The filament has to be cut at an optimal angle to feed easily during a spool change on my system.  3) Figure out how to get Flex to feed through the system and design changes to enable it.<<<

RE: Survey for happy MMU2 users only

A) 7

B) 15hours

C) every 100 to 200 filament change

D) 100% PLA

E) Alot, and only with these mods I brought it to the above manual intervention rate, before I was at about every 2nd filament change. I modified following:

• got rid of the buffer
• placed the filament spool high above the printer to have a long distance of loose filament (short ptfe tube in front of each spool and MMU, that is my buffer)
• encolosure, but this does not affect the prints, just a nice environement
• new MMU selector with magnet under ball and spaced out area around ball for better cleaning
• new ptfe tube between mmu selector and extruder ID 2.5mm OD 4mm
• new ptfe tube (short tubes) between mmu selector and idler ID 2.5mm OD 4mm
• removed the razor blade

RE: Survey for happy MMU2 users only

A) Over 50

B) Not recorded the duration, 2000 tool change is the longest print I did.

C) every 100 tool change at the begining, 400 - 500 today

D) 
- PLA Filament 0 % ?
- ABS Filament  0% ?
- PET/PETG Filament 99 % ?
- Other HT materials 0 % ?
- Flex  + PETG 1 % ?

E) Y , Extuder assembly, selector, https://www.prusaprinters.org/prints/1957-prusa-i3-mk3s-r4-extruder-mmu2s-with-path-through-

RE: Survey for happy MMU2 users only

A) Over 100

B) 5 - 8 hours

C) once every 10 or so prints

D) 
- PLA Filament % 98
- ABS Filament % 0
- PET/PETG Filament % 2
- Other HT materials % 0
- Flex % 0

E) Y - Changed to 3mm inner diameter PTFE tubes, different filament buffer

Originally I had several problems with the MMUS2, however after changing the PFTE tubes, using a better filament buffer (with bearings) and changing the ramming settings in the slicer the systems works every well. Occasionally I will get a problem with a tip on the filament, but this would be only once every 10 or so prints (usually 500+ tool changes in most prints). 

I mainly print with eSun PLA+ but also use some Prusament as well. Not sure if that makes any difference as I had my settings dialed in for those filaments before installing the MMU2s

Hope this helps, and I am always happy to give tips to anyone have problems.