MMU Gear Chewing Up Filament
I'm not sure if this is happening during loading or unloading, but the MMU bondtech gear is chewing up the filament, producing a significant amount of confetti.
Has anyone else seen this and know how to address it? I recalibrated the bowden length multiple times following the individual filament calibration guide, I'm using amazon branded pla filament with default settings.
It printed these without issue while producing that amount of confetti so it's not impacting printing, but having to vacuum up after any long print job is not ideal.
Re: MMU Gear Chewing Up Filament
I would mess with the tension screws, and make sure the filament has a clear path, the fact its on all of them maybe look into the cap of the extruder
hey just thought of this. check and make sure that part that holds down the 5 PTFE tubes isn't too tight.
I have a Prusa,therefore I research.
Re: MMU Gear Chewing Up Filament
Set "Loading speed at the start" to 19 mm/s
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…
Re: MMU Gear Chewing Up Filament
thought they fixed that in firmware?
I have a Prusa,therefore I research.
Re: MMU Gear Chewing Up Filament
thought they fixed that in firmware?
Latest MMU firmware from GitHub, just now:
void load_filament_inPrinter()
{
// loads filament after confirmed by printer into the Bontech pulley gears so they can grab them
uint8_t current_running_normal[3] = CURRENT_RUNNING_NORMAL;
uint8_t current_running_stealth[3] = CURRENT_RUNNING_STEALTH;
uint8_t current_holding_normal[3] = CURRENT_HOLDING_NORMAL;
uint8_t current_holding_stealth[3] = CURRENT_HOLDING_STEALTH;
if (isIdlerParked) park_idler(true); // if idler is in parked position un-park him get in contact with filament
set_pulley_dir_push();
//PLA
tmc2130_init_axis(AX_PUL, tmc2130_mode);
for (int i = 0; i <= 320; i++)
{
if (i == 150)
{
if(tmc2130_mode == NORMAL_MODE)
tmc2130_init_axis_current_normal(AX_PUL, current_holding_normal[AX_PUL], current_running_normal[AX_PUL] - (current_running_normal[AX_PUL] / 4) );
else
tmc2130_init_axis_current_stealth(AX_PUL, current_holding_stealth[AX_PUL], current_running_stealth[AX_PUL] - (current_running_stealth[AX_PUL] / 4) );
}
do_pulley_step();
delayMicroseconds(2600);
}
//PLA
if(tmc2130_mode == NORMAL_MODE)
tmc2130_init_axis_current_normal(AX_PUL, current_holding_normal[AX_PUL], current_running_normal[AX_PUL]/4);
else
tmc2130_init_axis_current_stealth(AX_PUL, current_holding_stealth[AX_PUL], current_running_stealth[AX_PUL]/4);
for (int i = 0; i <= 450; i++)
{
do_pulley_step();
delayMicroseconds(2200);
}
park_idler(false);
tmc2130_disable_axis(AX_PUL, tmc2130_mode);
}
Still the same delays between steps. the 2,600 delay generates 380 steps/second at 1/2 stepping = 19mm/s for about 7.5mm, then 2,200 delay generates about 450 steps/second at 1/2 stepping = 22.5mm/s for about 22.5mm, but at much lower current, allowing the MMU drive pulleys to be puled rather than skip.
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…
Re: MMU Gear Chewing Up Filament
Dear all
I am a complete beginner, no knowledge about firmware and stuf, but what I see on my filament is that there is a litte piece of filament "bitten" everey 3 to 5 cm or so, additionlay there is clearly a feelon the filament that on one side tooth-gear has cut into the plastic.
Did I tighten my MMU2 to hard or is this a genereal assambly error by
What can I do?
Sascha
Re: MMU Gear Chewing Up Filament
Dear Brandon
Same issue here 
Please beware that FINDA -Holder will have filament residues inside either, you have to clean this too
Maybe you should tighten the selector with less force seemed to work for me, even now I have some Filament loading issues
sascha
Re: MMU Gear Chewing Up Filament
I'm not sure if this is happening during loading or unloading, but the MMU bondtech gear is chewing up the filament, producing a significant amount of confetti.
1. Run for each tube a length calibration
2. Set the "Loading speed at the start" to something between 15-20mm/s
3. Update the MMU/MK3 firmware and Slic3r (don't forget to reset the filament configurations) to the most recent version
After this steps grinding should disappear.
Often linked posts:
Going small with MMU2
Real Multi Material
My prints on Instagram
Re: MMU Gear Chewing Up Filament
For me it grinds during the fast unload session, the fast load is smoth and nice