Improvements to the MMU 2.0 controller firmware  

Re: Improvements to the MMU 2.0 controller firmware

Trying this firmware because I've given up hope on the MMU 2.0. Is there an easy way to calibrate the individual filament length? I'm seeing that there's an option on putting a custom value in a file but I have no idea what values to use to dial it in. I'm currently printing a 4 color print and 3 of the 4 colors grind really loud and the 4th never feeds to the Bondtech gear.

Re: Improvements to the MMU 2.0 controller firmware

Trying this firmware because I've given up hope on the MMU 2.0. Is there an easy way to calibrate the individual filament length? I'm seeing that there's an option on putting a custom value in a file but I have no idea what values to use to dial it in. I'm currently printing a 4 color print and 3 of the 4 colors grind really loud and the 4th never feeds to the Bondtech gear.

Did you try this Mod ?

https://shop.prusa3d.com/forum/general-discussion-announcements-and-releases-f53/mmu2-another-solution-for-layer-skipping-due-to-fi-t25334.html#p115345

it solved a lot of issues for me. And stting the feed rate from 3 to 19mm/s

Re: Improvements to the MMU 2.0 controller firmware

Hey Dryja123,

There isn't presently a way to adjust on the fly.

If you're getting grinding then you're tube is probably less than 350mm as this was my stock one.
My guess is that not everyone got a stock 350mm.

The mod bellow is also not a solution to this firmware, fine for getting around stock FW issues.

First, ensure your Slic3r advanced settings are as per the readme as this will definitely cause grinding.
Secondly, try dropping the BOWDEN_LENGTH variable down 300 steps from 8000 to accommodate for the shorter tube.

Trying this firmware because I've given up hope on the MMU 2.0. Is there an easy way to calibrate the individual filament length? I'm seeing that there's an option on putting a custom value in a file but I have no idea what values to use to dial it in. I'm currently printing a 4 color print and 3 of the 4 colors grind really loud and the 4th never feeds to the Bondtech gear.

Did you try this Mod ?

https://shop.prusa3d.com/forum/general-discussion-announcements-and-releases-f53/mmu2-another-solution-for-layer-skipping-due-to-fi-t25334.html#p115345

it solved a lot of issues for me. And stting the feed rate from 3 to 19mm/s

Re: Improvements to the MMU 2.0 controller firmware

Hey Dryja123,

There isn't presently a way to adjust on the fly.

If you're getting grinding then you're tube is probably less than 350mm as this was my stock one.
My guess is that not everyone got a stock 350mm.

The mod bellow is also not a solution to this firmware, fine for getting around stock FW issues.

First, ensure your Slic3r advanced settings are as per the readme as this will definitely cause grinding.
Secondly, try dropping the BOWDEN_LENGTH variable down 300 steps from 8000 to accommodate for the shorter tube.

Awesome, thank you for the reply. I did make the changes to the slicer, per the Readme, but I will go back and modify the BOWDEN_LENGTH variable.

Regarding the mod, I did see it and didn't use it because it's a bandaid. Slapping a bandaid on an issue isn't fixing it.

Thanks for your hard work on this custom firmware!

Re: Improvements to the MMU 2.0 controller firmware

Robert,

I cannot seem to get my selector to home correctly and cannot determine why.

The idler seems to home correctly (assuming banging off one end a few times is correct). Then, the selector move to the far right smoothly and quickly.

But, when the selector attempts to move back to the left, it only get to roughly the 5th filament position and then vibrates loudly without any additional movement.

The selector then moves back to the far right, back a bit to the left and then stops.

This sequence will happy repeat again and again if I press the middle button.

I pulled my selector and filed/sanded the sections that were printed a bit rough. . Did the same to the little block that retains the short PTFE tube segments between the hobbed gears and the selector.

Without the selector motor, the selector moves smoothly from end to end without contacting any other components. I'm certain there is no physical interference.

But, I still cannot get the selector to move to the far left and home correctly.

Any suggestions?

BTW, I have never noticed any selector issues with stock FW.

Re: Improvements to the MMU 2.0 controller firmware

I managed to solve my own problem.

After watching the failure many additional times looking for physical interference, I suddenly realized that the selector was still accelerating when it failed. That made me wonder if it was trying to accelerate to a speed higher than my particular MMU would support as the vibrating I get does look like a stepper driven beyond its steps/second limit.

I pulled the tree from github and dug through motion.cpp to review the selector homing code. After seeing how that all worked, I modified config.h and changed MAX_SPEED_SEL from 8000 down to 5000.

Viola! I now get 100% reliable selector homing.

My plan is to test a bit more to see where it breaks between 5000 and 8000.

Re: Improvements to the MMU 2.0 controller firmware

i have found some weird homing issues.
https://shop.prusa3d.com/forum/hardware-firmware-and-software-help-f56/mmu2-homing-issue-t26043.html

maybe this is related and should be reported.

Re: Improvements to the MMU 2.0 controller firmware

daniel.a6.....what my unit was doing looks very different than the behavior in your video. What you had is really puzzling, but I do not think it is the same velocity issue I experienced.

robert.m28.....I do not know where my unit is along the distribution of units. but, mine works 100% with a selector velocity of 7,100 or below. It will fail once every 12-15 homing attempts at 7,300, and once every 4-5 at 7,500.

Re: Improvements to the MMU 2.0 controller firmware

Robert,

I cannot seem to get my selector to home correctly and cannot determine why.

The idler seems to home correctly (assuming banging off one end a few times is correct). Then, the selector move to the far right smoothly and quickly.

But, when the selector attempts to move back to the left, it only get to roughly the 5th filament position and then vibrates loudly without any additional movement.

The selector then moves back to the far right, back a bit to the left and then stops.

This sequence will happy repeat again and again if I press the middle button.

I pulled my selector and filed/sanded the sections that were printed a bit rough. . Did the same to the little block that retains the short PTFE tube segments between the hobbed gears and the selector.

Without the selector motor, the selector moves smoothly from end to end without contacting any other components. I'm certain there is no physical interference.

But, I still cannot get the selector to move to the far left and home correctly.

Any suggestions?

BTW, I have never noticed any selector issues with stock FW.

Hi Greg,

I had exactly the same issue after having disassembled the selector unit.
Try to untighten the selector motor and then press the cancel button on the printer to launch the rehoming sequence, even if your selector moves smoothly when motor removed, It does not mean that the motor's lead screw is perfectly aligned with selector shafts when tightening it, tighten gradualy the motor after several rehoming.
It's in relation with the Trinamic stallguard used in Robert's firmware, when a excessive resistance is detected in the moves, the motor stops

Re: Improvements to the MMU 2.0 controller firmware

Over the last week, I keep getting the drum rehoming time after time on filament changes.

Filament will retract fully, then when the selector is about to move to the new position, the drum homes, for minutes on end. Sometimes only a few times, but often 10's of times until 2-5 minutes goes by.

If it stops before the mk3 notices, the print continues. If the mk3 times out, it'll do the "press a button on the mmu" which I think automatically clears, but it won't load filament and you'll get a skipped line.

It's happened often on the first material change, even occasionally on the first load. I suspect since it self clears it happens often when I'm not in the room, I'll hear it from across the house sometimes.

I'm running MP-1 right now, otherwise reliable. I think I've seen this on other firmware (both OEM and ZB).

Any ideas?

Video: https://photos.app.goo.gl/N6MVfBBD5BQCVknW6
Note: It started on its own, and although I reached around the back at the end, I didn't touch anything before it "fixed"

Re: Improvements to the MMU 2.0 controller firmware

OK, THAT's interesting.

If I push down on the MMU, effectively tightening the tensions screws, the period goes down - like, 30% faster.

I lifted slightly and the very next homing was the last. That's far from predictive, but could it be rehoming until it sees a repeating value?

Re: Improvements to the MMU 2.0 controller firmware

MK3 5.0.2 firmware commit 6b14576
MMU 2.1.3 firmare commit 7f0e782

I could not complete this model with roberts firmware. Seems like it has a logic issue. I outlined the issue on page14 but never got a response. I've gone back to stock and was able to complete this 27h 22m torture test.
https://www.thingiverse.com/thing:2807122

Re: Improvements to the MMU 2.0 controller firmware

MK3 5.0.2 firmware commit 6b14576
MMU 2.1.3 firmare commit 7f0e782

I could not complete this model with roberts firmware. Seems like it has a logic issue. I outlined the issue on page14 but never got a response. I've gone back to stock and was able to complete this 27h 22m torture test.
https://www.thingiverse.com/thing:2807122

20181202_155052.jpg

Thats a really lovly print.

Re: Improvements to the MMU 2.0 controller firmware

Looks great!

How much wipe did you use to keep the black from bleeding?

Re: Improvements to the MMU 2.0 controller firmware

Looks great!

How much wipe did you use to keep the black from bleeding?

i keep notes and update them after prints. I wish slic3r saved this info
Advanced purge:
HatchBox True Black > Solutech3D White: 210 or 220
eSun Fire Engine Red > Solutech3D White: 230 still had slight bleeding

Re: Improvements to the MMU 2.0 controller firmware

MK3 5.0.2 firmware commit 6b14576
MMU 2.1.3 firmare commit 7f0e782

I could not complete this model with roberts firmware. Seems like it has a logic issue. I outlined the issue on page14 but never got a response. I've gone back to stock and was able to complete this 27h 22m torture test.
https://www.thingiverse.com/thing:2807122

20181202_155052.jpg

Thats a really lovly print.

Thank you, Im proud of it. Peter keeps show me up however

Re: Improvements to the MMU 2.0 controller firmware

So I printed a new drum which DOES NOT slip, as it has a gear inside. ( https://shop.prusa3d.com/forum/hardware-firmware-and-software-help-f56/selector-drum-that-won-t-slip-or-split-t26342.html )

I think it may have helped slightly, but the problem still exists.

Anyway, I've installed an indirect filament sensor and would like to know how to adjust things since the distance from sensor to bondtechs is now ~32 mm vs like 20, and to know which version is the most worth trying. Rob, any suggestions?

Re: Improvements to the MMU 2.0 controller firmware

To set Optical Filament Sensor to Bondetch Distance, I modified line 32 of Motion.cpp:
const int STEPS_MK3FSensor_To_Bondtech = 756; //Abe 385 original number, I need to modify 385 by 191% (32mm/16.5mm) = 755.xxx

--------------------results--------------------
Running the latest of everything, the changes go very well! I heard NO grinding, which is awesome! I've noticed the feeds and retracts are significantly slower, and I don't know if I agree, I've never had problems with the faster feeds of MP-1.

My first print made some 5-10 layers before a unfeeding stopped some 3cm short of the sensor ball. Not sure why. I had several issues on the next couple feeds, then one retraction where nothing seemed to be wrong, the printer was waiting for the MMU, and just nothing happened. I pressed every button on MMU, the printer button, waited 20+ minutes, pressed everything again.... But it was just done. I had no choice but to reset.

The next print went just fine, but I am getting warping on my objects, possibly new fan duct isn't up to snuff. Will try something longer/bigger now.

Re: Improvements to the MMU 2.0 controller firmware

I had several issues on the next couple feeds, then one retraction where nothing seemed to be wrong, the printer was waiting for the MMU, and just nothing happened. I pressed every button on MMU, the printer button, waited 20+ minutes, pressed everything again.... But it was just done. I had no choice but to reset.

This is why I reverted to stock. Over all I love the changes Robert has made, especially if u are able to use indirect filament sensor. But if printer becomes unresponsive your dead in the water no matter what.

Re: Improvements to the MMU 2.0 controller firmware

MK3 5.0.2 firmware commit 6b14576
MMU 2.1.3 firmare commit 7f0e782

I could not complete this model with roberts firmware. Seems like it has a logic issue. I outlined the issue on page14 but never got a response. I've gone back to stock and was able to complete this 27h 22m torture test.
https://www.thingiverse.com/thing:2807122

Hi khalil.n,

What a lovely print 👏👍

Is the issue you're referring to when it becomes dead in the water?