Extruder Motor Issue!

ABigBirch · 2016-09-28T17:11:54.000Z

Yes, it extrudes easily by hand.

ABigBirch · 2016-09-28T17:16:21.000Z

I’ve checked the stepper drivers, and they all work. The hot end and PTFE tube also work fine.

wirlybird · 2016-09-28T17:26:14.000Z

It seems down to a few things. Bad cable or bad board. Unless there is some other “pinch” point that is getting overlooked.

I had a filament feed issue and found the spool was working its way out on the holder then rubbing and causing resistance.

Does it still do it if you feed filament directly by hand?

ABigBirch · 2016-09-28T17:33:09.000Z

Yes, unless I push the filament through with a lot of force. The motor is unable to push it through by itself, but with a lot of help it will extrude.

MindFuLL · 2016-09-28T17:39:15.000Z

In addition to the good advice of @wirlybird has given, you could also adjust the current on the stepper driver. Depending on the drivers you have, this is usually adjusted by turning a physical trim pot on the driver itself with a small screw driver.
-Jesse

ABigBirch · 2016-09-28T17:45:25.000Z

Right now it’s set to the default current, and I know that I have to turn it clockwise to increase it. Is there a threshold I should avoid?

MindFuLL · 2016-09-28T17:52:53.000Z

Unless you have a multi-meter to check the Vref pin, the best metric is to monitor the heat. If the motor and/or driver is running very hot to the touch(warm is okay) then you want to turn it down.
-Jesse

Derek_Tolliver · 2016-09-29T09:49:31.000Z

What kind of printer is it? Are the two wheels that push the material clean? They can get gummed up and no longer grip the material. Are the two wheels under tension? When the material is pushed through the wheels, the material should have little dimples in it where the wheels grip tight.

DreamSpace · 2016-09-29T10:20:21.000Z

I have had the same problem countless times and the main causes that I have found on my printer is that when the extruder gets too hot the heat creeps up the barrel and melts some of the plastic inside it, making it harder to get filament through. If I were you I would replace the barrel and maybe the nozzle. Also check the vref of the extruder motor and look up what it is supposed to be. I believe it’s somewhere around. 6 vref. I have noticed it helps to turn the extruder one up a bit to give it a little more current and power to turn the motor. I personally never liked the little peice of tubing in the barrel no matter what material it’s made of… I usually take that out

martin_p · 2016-09-29T11:16:02.000Z

What if you try to push manually the filament through the extruder? Does the material come out? It shall come out very easily. I had also an issue with the extruder and in the end it was the toothed sprocket misaligned with the wire because the PLA extruder body was deformed. It was very small offset but was enough to prevent filament to be pushed out.

ProtoPlastik · 2016-09-29T12:44:41.000Z

What hot end are you using? In my experience, poor feed is the result of the following:

- low temperature

- on e3D hot ends, check the PTFE tube. They should be replaced occasionally. If you’re not sure, replace it anyway.

- also on e3D, make sure the heater block, nozzle, and barrel are all tight

- drive gear alignment with the tension bearing

- drive gear clogged

- drive gear slipping

Run the stepper without it being installed. Check to make sure motion is smooth. Bad cable is a possibility. Also check the header on the board. If you replaced the motor with similar results, it’s not likely the motor. Could be current, low current will cause the motor to “clutch” and that produces an audible clicking sound.

Ronca · 2016-09-29T12:49:09.000Z

Hi there

In your shoes I wolud check and/or rise the Vref value of the pololu of the referred extruder motor.

I rised up the Vref over the suggested value. The motor is a little bit warm during the whole (long) printing, but it works just fine.

Ciao

CollectorCNC · 2016-09-29T13:20:23.000Z

Try lubricating your filament. Do one drop of canola oil on the end of your filament then feed it in. Also you can take a paper towel and a binder clip to make an oiler that lubes the filament before it enters your ptfe tubing. I find that especially with PLA, this really helps on both my direct drive and Bowden printers.

ABigBirch · 2016-09-29T13:44:53.000Z

I do this almost every time I reload the filament, it doesn’t seem to do much for ABS or PLA. Thanks for the help though.

ABigBirch · 2016-09-29T13:48:32.000Z

How would I go about changing this? I have tried to adjust the current, but it didn’t seem to do anything. I just need a bit more detail, this is my first printer I have owned.

christiangentry · 2016-09-29T14:26:17.000Z

There’s rarely an issue with the stepper motors. I’ve had feeding trouble, also, and it’s always been a mechanical issue such as the tension spring had too much or too little tension.

One other factor you may not be thinking about is thermal issues. If the ambient temperature in your printing area is too cold, you will have trouble with feeding.

Can you respond with specific details about what you’re seeing? For instance, when you preheat the hotend, then extrude do you see the hob rotate and chew up the filament? Does the hob NOT move? I think if you can paint a clearer picture for us we could help more.

ABigBirch · 2016-09-29T14:37:30.000Z

The stepper motor does not run smoothly, it will rotate on its own when it is not installed, but it has a very jerky motion. It’s a new motor, and the old motor does the same thing when connected to that cable.

ABigBirch · 2016-09-29T14:43:51.000Z

The filament does not get chewed up and the and there hasn’t been anything wrong with the temperatures. (I installed my hot end on another printer, and it worked fine) The motor doesn’t seem to have enough strength to push the filament through, it is unable to strip the plastic off the filament. It twitches back and forth when it hits any resistance. The hot end is also completely clear of all plastic debris.

christiangentry · 2016-09-29T14:44:17.000Z

If the same behavior is occurring with different motors, then the issue is likely not the motors. It could be a physical issue with your controller board such as power delivery or firmware. Also, wiring is always a possibility. “Jerky” sounds like a bad connection, so that may be a good place to start.

ABigBirch · 2016-09-29T14:47:52.000Z

It is a modified Prusa i3 printer, the whole extruder assembly is completely clean and free of debris. The two wheels are under the correct tension. The plastic does have the small dimples. When the filament does not extrude, it is not being stripped either, the motor simply twitches back and forth, like it’s too weak to do the job.