Week 3  

Re: Week 3

ray.a I live in SW Florida and print in a garage also so I feel your pain on wet filament. I have found it helps to store in in a vacuum bag with desiccant. I figure less air less humidity. I use those bags that are used for seasonal storage of winter gear and heavy blankets. They already have a vacuum valve and all you need is a vacuum cleaner to use them.

Hope that helps,

Neal

Re: Week 3

ray.a I live in SW Florida and print in a garage also so I feel your pain on wet filament. I have found it helps to store in in a vacuum bag with desiccant. I figure less air less humidity. I use those bags that are used for seasonal storage of winter gear and heavy blankets. They already have a vacuum valve and all you need is a vacuum cleaner to use them.

Hope that helps,

Neal

I don't know whether this would help with humidity: https://www.repkord.com/products/repbox-filament-storage-solution

Peter

Re: Week 3

There may be another temporary work-around:

Image1.png

Can you try setting the "Loading speed at start" value to 19 mm/s for all filament, slice a small model and try that. Things should improve slightly. You could also try setting the "Loading speed" to 22 mm/sec for all filaments.

This is an attempt to match the Bondtech speed with the MMU.

Peter

Mr. P!
Can you explain this? Which one is doing what?
Right now I'm running it, and I still get filament being slammed and butted against stationary gears.

Some time ago I set the "Extra Loading Distance" from "-13" (under printer settings/mm setup) to "-3" in the hopes of not ramming AS MUCH into the stationary gears.

So far I'm racking up failures trying this, though I like the idea.

Re: Week 3

Mr. P!
Can you explain this? Which one is doing what?
Right now I'm running it, and I still get filament being slammed and butted against stationary gears.

Some time ago I set the "Extra Loading Distance" from "-13" (under printer settings/mm setup) to "-3" in the hopes of not ramming AS MUCH into the stationary gears.

So far I'm racking up failures trying this, though I like the idea.

Well, there's not a lot to explain really. The MMU firmware does 2 loads, one after the other with slightly different speeds and different motor power.

The first feed is 321 steps with a loop delay of 2,600 micro seconds
The second feed it 451 steps with a loop delay of 2,200 micro seconds.

The second feed is carried out with a motor power that is insufficient to drive the pulleys 🙁 Also the motor current is reduced about half way through the first feed.

From my reading of the firmware source, the filament drive pulleys were intended to be driven at 1/16 microstepping. However and for whatever reason, 1/2 microstepping is actually being used, which means driving 8 times as much filament (40 mm) at 8 times the speed (about 20 mm/s) - but the problem is the second (larger) feed which is not really being "driven".

I have amended the firmware to drive 32 mm at 6 mm/sec, all with a higher motor current.

My thoughts are to try to match the printer to the existing firmware, in the hope that some will be successful.

If anyone is interested in my amended firmware, here is my fix (motion.cpp):

void load_filament_inPrinter()
{
if (isIdlerParked) park_idler(true); // if idler is in parked position un-park him get in contact with filament
set_pulley_dir_push();
tmc2130_init_axis_current(0, 1, 24);
for (int i = 0; i < 640; i++)
{
do_pulley_step();
delay (8);
}
tmc2130_init_axis_current(0, 1, 0);
park_idler(false);
tmc2130_init_axis_current(0, 0, 0);
}

Note that at 1/2 stepping, there are ~ 20 steps/mm. And I agree that this code is neither elegant nor precise.

Peter