elizabeth.f2
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Re: MMU2 Troubleshooting

Dec 18, 2018 1:34 am

My MMU2 makes a squealy noise when it is just sitting at rest. Why is that? How do i fix it? I can hear it even when it is printing, too.

juan.p4
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Re: MMU2 Troubleshooting

Jan 02, 2019 9:44 pm

Flashing my MMU2 has failed, now it is not working, the log is:

avrdude: Version 6.3-20160220-prusa3d, compiled on Nov 22 2018 at 15:22:47
Copyright (c) 2000-2005 Brian Dean, http://www.bdmicro.com/
Copyright (c) 2007-2014 Joerg Wunsch

System wide configuration file is "C:/PROGRA~1/Prusa3D/Slic3rPE/resources\avrdude\avrdude.conf"

Using Port : COM15
Using Programmer : avr109
Overriding Baud Rate : 57600
AVR Part : ATmega32U4
Chip Erase delay : 9000 us
PAGEL : PD7
BS2 : PA0
RESET disposition : dedicated
RETRY pulse : SCK
serial program mode : yes
parallel program mode : yes
Timeout : 200
StabDelay : 100
CmdexeDelay : 25
SyncLoops : 32
ByteDelay : 0
PollIndex : 3
PollValue : 0x53
Memory Detail :

Block Poll Page Polled
Memory Type Mode Delay Size Indx Paged Size Size #Pages MinW MaxW ReadBack
----------- ---- ----- ----- ---- ------ ------ ---- ------ ----- ----- ---------
eeprom 65 20 4 0 no 1024 4 0 9000 9000 0x00 0x00
flash 65 6 128 0 yes 32768 128 256 4500 4500 0x00 0x00
lfuse 0 0 0 0 no 1 0 0 9000 9000 0x00 0x00
hfuse 0 0 0 0 no 1 0 0 9000 9000 0x00 0x00
efuse 0 0 0 0 no 1 0 0 9000 9000 0x00 0x00
lock 0 0 0 0 no 1 0 0 9000 9000 0x00 0x00
calibration 0 0 0 0 no 1 0 0 0 0 0x00 0x00
signature 0 0 0 0 no 3 0 0 0 0 0x00 0x00

Programmer Type : butterfly
Description : Atmel AppNote AVR109 Boot Loader

Connecting to programmer: Found programmer: Id = "CATERIN"; type = S
Software Version = 1.0; No Hardware Version given.
Programmer supports auto addr increment.
Programmer supports buffered memory access with buffersize=128 bytes.

Programmer supports the following devices:
Device code: 0x44

avrdude: devcode selected: 0x44
avrdude: AVR device initialized and ready to accept instructions

Reading | ################################################## | 100% 0.00s

avrdude: Device signature = 0x1e9587 (probably m32u4)
avrdude: safemode: hfuse reads as D8
avrdude: safemode: efuse reads as CB
avrdude: reading input file "C:\Users\Juan\Downloads\prusa3d_fw_3_5_1_MK3_1_0_3_MMU2\prusa3d_fw_MMU2board_1_0_3.hex"
avrdude: writing flash (19966 bytes):

Writing | ################################################## | 100% 1.48s

avrdude: 19966 bytes of flash written
avrdude: verifying flash memory against C:\Users\Juan\Downloads\prusa3d_fw_3_5_1_MK3_1_0_3_MMU2\prusa3d_fw_MMU2board_1_0_3.hex:
avrdude: load data flash data from input file C:\Users\Juan\Downloads\prusa3d_fw_3_5_1_MK3_1_0_3_MMU2\prusa3d_fw_MMU2board_1_0_3.hex:
avrdude: input file C:\Users\Juan\Downloads\prusa3d_fw_3_5_1_MK3_1_0_3_MMU2\prusa3d_fw_MMU2board_1_0_3.hex contains 19966 bytes
avrdude: reading on-chip flash data:

Reading | ################################################## | 100% 0.14s

avrdude: verifying ...
avrdude: verification error, first mismatch at byte 0x0980
0xff != 0x1f
avrdude: verification error; content mismatch

avrdude: safemode: hfuse reads as D8
avrdude: safemode: efuse reads as CB
avrdude: safemode: Fuses OK (E:CB, H:D8, L:FF)

avrdude done. Thank you.

michael.c31
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Re: MMU2 Troubleshooting

Jan 10, 2019 5:56 pm

PJR wrote:
Aug 29, 2018 10:00 pm

The extruder motor current was set to a rather high value (30) in earlier firmware. The new R3 printed extruder body allows you to print with lower E-motor power and therefore a cooler E-motor. Motor current is set as follows:

Code: Select all

M911 Enn ; Set the E motor holding current to nn M912 Enn ; Set the E motor printing current to nn M913 ; View the motor current settings

Be aware that motor current may be altered during tool changes (I have not checked the firmware for this as yet) so if you want to change it, it may be that you will need to reset your value after every tool change. Personally, I have currents set at 20 for printing, 30 during a tool change (unloading) and 20 for holding. When working on the printer (cold pull etc) I simply set holding current to zero.
Peter
do you know how do make this change from slic3r? also if i try to just send this command i get the following.

Code: Select all

Send: M913 Recv: Unknown M code: M913 Recv: ok
also the nearest match i can find in the gcode is as follows. which doesn't really line up with this example.

Code: Select all

M907 E550

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PJR
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Re: MMU2 Troubleshooting

Jan 10, 2019 8:34 pm

michael.c31 wrote:
Jan 10, 2019 5:56 pm
Peter
do you know how do make this change from slic3r? also if i try to just send this command i get the following.

Code: Select all

Send: M913 Recv: Unknown M code: M913 Recv: ok
also the nearest match i can find in the gcode is as follows. which doesn't really line up with this example.

Code: Select all

M907 E550
M912 and M913 were implemented prior to firmware version 3.5. Latest firmware uses M907 and both holding and running currents are set to the same value :( which prevents lowering the holding current to reduce heat.

M907 E550 causes the motor current to go even higher than M912 E30, and the manner in which M907 has been implemented in firmware is not particularly great.

From memory, the values you needs are between 360 and 520.

Peter
Please note: I do not have any affiliation with Prusa Research. Any advices given are offered in good faith. It is your responsibility to ensure that by following my advice you do not suffer or cause injury, damage or loss.

rui.v
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Re: MMU2 Troubleshooting

Jan 11, 2019 11:48 am

Hi folks , the mmu2 has been working great for the past 2 months, I am experiencing an issue that I'm not sure what direction to take, during a mmu print the stepper motor that turns the drum not the filament selector, will lose I guess its power and becomes totally dead ( cold motor you can move it with a finger like its when the printer not powered) until the printer is at a state that requires user the interact. that's when I press the reset button on the mmu and the steppers start to home again and I select the right filament and then hit resume on the printer. I have checked all wires from the main board to stepper wires on the mmu. that's the only issues I have with it at the moment, both the printer and the mmu have been updated to the latest firmware since December.

thanks in advance

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Re: MMU2 Troubleshooting

Jan 13, 2019 10:40 am

rui.v wrote:
Jan 11, 2019 11:48 am
during a mmu print the stepper motor that turns the drum not the filament selector, will lose I guess its power and becomes totally dead
...
both the printer and the mmu have been updated to the latest firmware since December.
I think I would revert to the previous firmware to see if the problem persists. If it goes away, then you know it's the firmware, otherwise it's most likely hardware.

Peter
Please note: I do not have any affiliation with Prusa Research. Any advices given are offered in good faith. It is your responsibility to ensure that by following my advice you do not suffer or cause injury, damage or loss.

rui.v
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Re: MMU2 Troubleshooting

Jan 13, 2019 1:20 pm

PJR wrote:
Jan 13, 2019 10:40 am
rui.v wrote:
Jan 11, 2019 11:48 am
during a mmu print the stepper motor that turns the drum not the filament selector, will lose I guess its power and becomes totally dead
...
both the printer and the mmu have been updated to the latest firmware since December.
I think I would revert to the previous firmware to see if the problem persists. If it goes away, then you know it's the firmware, otherwise it's most likely hardware.

Peter
Thanks Peter, I will give that a go.

andy.q
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Re: MMU2 Troubleshooting

Feb 03, 2019 4:17 pm

Just noticed that when cancelling a print through Octoprint, if I'm printing on an extruder other than 1, the printer raises slightly from the bed, unloads the current extruder back to the MMU unit and then re-loads filament from extruder 1 down to the nozzle. Then the printhead moves to the side and the print then cancels.

I checked the OctoPrint Cancel G-Code which is below, but this seems to not be the cause. Any ideas?


--------
;dock
G91 ;relative positioning

; Commented this out to see if it stops the reloading of extruder 1 - it doesn't!
;G1 E-1 F300 ;retract the filament a bit before lifting the nozzle, to release some of the pressure
;G1 Z+5 E-5 F9000 ;move Z up a bit and retract filament even more

G1 Z+5 F9000 ; Move Z up

G90 ; absolute positioning

T0
G1 X0 Y200 F3000

; disable motors
M84

;disable all heaters
;{% snippet 'disable_hotends' %}
;{% snippet 'disable_bed' %}

;disable fan
M106 S0

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Re: MMU2 Troubleshooting

Feb 03, 2019 8:41 pm

andy.q wrote:
Feb 03, 2019 4:17 pm
Just noticed that when cancelling a print through Octoprint, if I'm printing on an extruder other than 1, the printer raises slightly from the bed, unloads the current extruder back to the MMU unit and then re-loads filament from extruder 1 down to the nozzle. Then the printhead moves to the side and the print then cancels.

I checked the OctoPrint Cancel G-Code which is below, but this seems to not be the cause. Any ideas?


--------
;dock
G91 ;relative positioning

; Commented this out to see if it stops the reloading of extruder 1 - it doesn't!
;G1 E-1 F300 ;retract the filament a bit before lifting the nozzle, to release some of the pressure
;G1 Z+5 E-5 F9000 ;move Z up a bit and retract filament even more

G1 Z+5 F9000 ; Move Z up

G90 ; absolute positioning

T0
G1 X0 Y200 F3000

; disable motors
M84

;disable all heaters
;{% snippet 'disable_hotends' %}
;{% snippet 'disable_bed' %}

;disable fan
M106 S0
Instead of the T0, you should have something along these lines:

Code: Select all

G1 E5 F150 G1 E-15 F6000 ; Initial retract to get filament out without stringing G1 E-10 F1000 ; retract filament in PTFE tube ( stages) G1 E-10 F500 G1 E-10 F250 G1 E-10 F125 G1 E-5 F64 G1 E-10 F125 G1 E-5 F125 G1 E-5 F125 G1 E-20 F2000 ; Remove filament to above drive pulley M702 C ; Unload filament
The other option (which I prefer) is to pull the next filament out of MMU, wait for a tool change and then cancel the print. This ensure you get a good tip on the unloaded filament.

Peter
Please note: I do not have any affiliation with Prusa Research. Any advices given are offered in good faith. It is your responsibility to ensure that by following my advice you do not suffer or cause injury, damage or loss.

andy.q
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Re: MMU2 Troubleshooting

Feb 03, 2019 9:03 pm

Ahhh Thanks! No idea how I didn't notice the T0 (but wouldn't have suspected it had anything to do with Extruder 0 anyway!).

Will test that out tomorrow!

Cheers
Andy

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