Fillement feeder stepper stops when print starts

[Jeroenvankuik 0]

Hello everyone. Hopefully someone much smarter than me can help me out here. after 2 years using my printer this occurred: When start printing from sd_card everything works fine. Bed is heating, extruder is heating,.. when hit the right temperature,.. extruder goes to the "home" position. Then it goes up towards the starting point of the print. At this time it feeds a little bit of filament just before the actual print starts. However when the actual print starts the (filament) stepper motor continuously starts going slightly forward and then backwards so no filament is fed into the extruder. However the printer keeps on going thinking that it is..

 

What have I done so far trying to solve this:

1) Calibrated the bed, and even lowered it to much to see if it feeds fillement without and obstruction due to the printing bed. This made no difference

2) Preheated the nozzle/extruder to 200c and then in the menu (moving x, y, z, extr) feeding the extruder, to my surprise this works perfectly. So there is no blockage of the filament and the stepper motor does work.

3) Just in case I switched the stepper motor with a spare one,. No difference.

 

So in short, up to the start of the actual printing, the extruder/stepper works fine, But when starting the actual print it does not feed filament anymore.

 

Just one bit of info that might help: I took out the extruder stepper (but kept it connected) and as mentioned the motor works great until the moment of actual printing starts. Then it does nothing anymore other then Turning a little bit back and forward. When this occurs the shaft/turning can be manipulated by hand. The same result was with the replacement stepper.

 

Can anyone make some sense out of all this?

 

Thank you so much in advance. Cheers Jeroen (Amsterdam, The Netherlands) 

 

Edited March 11, 2020 by Jeroenvankuik

[gr5 2,004]

1 hour ago, Jeroenvankuik said:

When this occurs the shaft/turning can be manipulated by hand.

That's not good.  That's the most telling part.  Three totally different possibilities:

 

1) Are you sure something isn't slipping on the shaft such that the stepper is fine but whatever is connected to the shaft is not?

 

2) There are gcodes that set current levels but that is different for different printers.  What kind of printer is this?

 

3) The controller board may be overheating.  Did you alter airflow?  Overheating stepper drivers automatically cut out (but so fast it's hard to tell what is going on as they can turn on and off a few times per second when overheating).

 

[P3D 46]

Maybe it isn't the stepper itself, but rather the stepper driver? Can you exchange the drivers on your board?

[Jeroenvankuik 0]

29 minutes ago, gr5 said:

That's not good.  That's the most telling part.  Three totally different possibilities:

 

1) Are you sure something isn't slipping on the shaft such that the stepper is fine but whatever is connected to the shaft is not?

 

2) There are gcodes that set current levels but that is different for different printers.  What kind of printer is this?

 

3) The controller board may be overheating.  Did you alter airflow?  Overheating stepper drivers automatically cut out (but so fast it's hard to tell what is going on as they can turn on and off a few times per second when overheating).

 

 

Thanks for your quick reply.

 

1) Are you sure something isn't slipping on the shaft such that the stepper is fine but whatever is connected to the shaft is not? I have detached everything from the shaft. So this occurs also with a clean shaft. Funny thing, when I stop the print and then go immediately to the menu (moving x, y, z, extr) the stepper works fine and filament feeds perfectly through the nozzle. This up to the moment I start printing again.

 

2) There are gcodes that set current levels but that is different for different printers.  What kind of printer is this?

I always use (for 2 years) the same G-code for a calibration cube. This file worked for the last 2 years. Until now.

(this problems occurs with new and old G-code files I upload to ythe printer via SD_card.

 

3) The controller board may be overheating.  Did you alter airflow?  Overheating stepper drivers automatically cut out (but so fast it's hard to tell what is going on as they can turn on and off a few times per second when overheating).

Airflow is good, Printer is also in my garage where the temp is quite low. Also when I turn off the printer for a few hours, then start up and print the problem is also there.

 

 

Pff, wish something was obviously broken, than it would be an easy fix 🙂

[Jeroenvankuik 0]

1 minute ago, P3D said:

Maybe it isn't the stepper itself, but rather the stepper driver? Can you exchange the drivers on your board?

 

Thank you for your reply. My printer is in a case. I will check the inside and see what I can find. I will make some pictures

[gr5 2,004]

What kind of printer is this - every printer has specific issues.

 

For example the Ultimaker 2 (but not original, or UM3 nor S5, nor S3) has something called "volumetric" mode and also it allows you to set the filament diameter to any value.  If you set the filament diameter to 10mm by accident it would do what you describe.  Somewhat.

 

I'd like to see the first 50 or so lines of gcode as it may be setting the current anyway - I just want to be really sure it doesn't set the current.

 

Okay another idea - something is wrong with the power supply.  Typically the servos and heaters run off somwhere from 12V to 24V (could be for example 19V).  If that voltage dips from 24V to 7V the circuit board will barely notice as it regulates that down to 5V anyway.  But the steppers will get weak.  So when everything is going at once the stepper may be weak.  Particularly if you have a bed heater.

 

Another idea - on UM2 and newer ultimaker printers there is a metal cover and the stepper cable can get caught and pinched under that cable and do weird things if the wire is exposed through the insulation.