Extrusion failure
Hi everyone. I am having a really troubling problem with my printer. It was working fine, then I went on vacation for 3 weeks, now I can't print anything. It seems that the extruder isn't delivering the flow rate that is being requested. I have been fighting this for a week now and I think I have eliminated all the usual suspects:
Recalibrated multiple times
Inspected hobbed bolt and idler (also checked fixing on stepper motor shaft)
Cold pulls from hotend come out clean
Adjusted filament idler tension
Cleaning filament (hand fed) extrudes fine
Changed filament and types of filament (PLA/ABS)
Calibrated feed rate. At slow feed rate calibration is good. At faster rate you get less.
I believe the hotend temperature is ok because I am using a PT100 and it registers ambient accurately when the heater is off.
The V2 calibration print looks almost ok sometimes. At other times the print gets thin and skips.
Below are two shots of the first layer of an ABS print. This is one of the Prusa Mk2 parts downloaded from the website, sliced using default ABS .2mm settings in Slic3r. I have also tried various prints from the SD card with pretty much the same results. There is no skipping sound from the extruder and I have not seen any evidence of "chewed" filament.
You can see that the feed rate is not sufficient to even fill in between the strokes.
I'm at my wit's end on this. I'm beginning to suspect electronics or the stepper motor itself. (I would include firmware, but it hasn't changed - 3.0.9).
If anybody knows the stepper motor shaft rotation rate for a given feed rate, I can measure the rate of rotation.
Anybody with any ideas on how to better diagnose/troubleshoot this please feel free...
Thanks,
Bob
Bob
Re: Extrusion failure
Have you tried a different roll of filament?
Sorry....just read that you have changed filaments.
Just grasping at straws on my end...but maybe check this extruder calibration video out.
Robert B.
Re: Extrusion failure
Looks as though you need to re-calibrate, especially Live Z Adjust.
Print the Prusa logo from the SD card and check the first layer.
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: Extrusion failure
... I believe the hotend temperature is ok because I am using a PT100 and it registers ambient accurately when the heater is off....
did you recompile your firmware for this temperature sensor, using [#define TEMP_SENSOR_0 147] inside your Configuration_prusa.h ?
otherwise you're reading false temperature values, even if your room temperature is shown correct.
furthermore, your 1st layer looks rubbish (live z adjustment incorrect). instead of calibrating the printer with the v2_calibration.gcode, check this method.
dem inscheniör is' nix zu schwör...
Re: Extrusion failure
Thanks for you suggestions.
I have changed filament with no real differences noted.
The firmware has been adjusted to the PT100 for some time. The printer was working fine with this sensor.
I have calibrated the filament feed rate (it was only off by about 3 percent)
I have done the live z-adjust (after every XYZ calibration). It is currently at -0.350
Here is a close-up of a V2Calibration print:
You can see how the line width starts out ok (it's good for about 50mm) and then shrinks. What is causing this?
Bob
Re: Extrusion failure
I have the same problem here.
Apparently the extuder pulley does not pull the filament properly. The pulley would turn fast, but very little filament was caught.
Re: Extrusion failure
Extract from V2Calibration.GCode:
G1 X50 Y155
G1 X75 Y155 E2.5
G1 X100 Y155 E2
G1 X200 Y155 E2.62773
...
Or
Position the extruder at 50,155
Move 25mm in X while extruding 2.5mm
Move 25mm in X while extruding 2mm
Move 100mm in X while extruding 2.62773mm
This results in the start of the first line being quite a bit thicker than the rest of the line.
So a thicker line at the start is exactly what to expect. You need to base your "Live Z" on the rest of the lines, not the starting 50mm.
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: Extrusion failure
I am experiencing the same issue. have you had any luck in fixing this? Is it normal for the stepper motor to slow way down after 3-5 seconds of "loading filament"? Is there a way to test the stepper feed rate?