Another problem with extruder feeding thread

[Napalm]

Hi,

I read through many threads now, to see if someone reports the same problem, but ...

Ok, I build a Prusa i3 pro b a few days ago and in the beginning everything seemed to work ok. Now, after a few days of printing and with bigger models I have the following problem, which seems to get worse every day. Yesterday I could not print anything, as the problem always started within the first 3 layers.

In the middle of printing, there is no more pla feed into the hot end. The Motor of the extruder is working, I can see the drive gear rotate. There is NO clicking sound. Everything seems to work wonderful and as expected, but the pla is not transported any more.
If I then push the pla a bit with my hand into the feeder everything works again, but sometimes only for a few minutes or seconds.

So the nozzle is not clogged, and it takes me only very little force to press the pla into the feeder. No force is needed to pull the pla form the spool.

To me it seems that the drive gear of the feeder is not grabbing the pla right or with not enough force.

My fist thought was, that it might be a problem with thickness of the pla, but I meanwhile tried 3 types of pla, and the pla which came with the printer. It is always the same.

I have the 'new feeder mechanism' which does not have a screw to change the force of the spring, so what can I do ?
(I think it is this one: http://www.geeetech.com/mk8-extruder-fe ... p-996.html)

regards
Mirko

[William]

OK,i think you can ask the seller for an entire kit or just a spring replacement.

[FernandoGarcia]

Hi!

I had similar issue with mine and it seems a design problem.

The spring doesn't provide enough pressure over the filament.

Removing the spring I see it curved.

To increase the pressure I did a small ghetto rig with things from my junk.

The main pieces are one screw and a conical nut.

See the pictures.

SAM_4706.jpg (48.44 KiB) Viewed 15426 times

SAM_4709.jpg (50.23 KiB) Viewed 15426 times

SAM_4710.jpg (37.71 KiB) Viewed 15426 times

SAM_4716.jpg (70.13 KiB) Viewed 15426 times

The screw I had to cut a small part.

Later is little hard to put the piece on place.

Too I changed the voltage on driver trimpot to 1.30 V.

I did prints yesterday during 8 hours without problems.

Let's see how many time it will work.

Best regards.

[FernandoGarcia]

Hi!

It was only a dream I have problems again. See the pictures:

Extruder problems (2).jpg (81.07 KiB) Viewed 15422 times

Extruder problems (3).jpg (99.28 KiB) Viewed 15422 times

Extruder problems (4).jpg (102.28 KiB) Viewed 15422 times

Extruder problems (5).jpg (90.22 KiB) Viewed 15422 times

Extruder problems (1).jpg (92.69 KiB) Viewed 15422 times

Extruder problems (6).jpg (61.62 KiB) Viewed 15422 times

This are the raft and two first layers of my print "finished".

When is printing the raft I had a fail and to help the extruder the filament was pressed with the hand to keep printing.

The extruder was not clogged.

I would like to know what the Geeetech will make to solve this problem.

Best regards.

[Toy]

Hi Fernando,
Seems the extruder doesn't have enough power to push the filament during printing.
You can try to incease the driver voltage, or swap the driver of extruder with other axis,
see if it will make any difference.

Refer to this link to adjust the voltage:
http://www.geeetech.com/forum/viewtopic ... 17&t=17038

[FernandoGarcia]

The voltage is 1.3V already.

[Toy]

Maybe the driver is overheated? Please make sure the driver is cooled well.

You can also disassemble the feeder to see if there's anything wrong:
http://www.geeetech.com/Documents/MK8%2 ... uction.pdf

[FernandoGarcia]

Hi!

Now I have two fans cooling the board.

I have swapped the Y and extruder motors.

The result:

SAM_4755.jpg (60.7 KiB) Viewed 15412 times

SAM_4756.jpg (62.79 KiB) Viewed 15412 times

SAM_4758.jpg (59.65 KiB) Viewed 15412 times

SAM_4760.jpg (64.85 KiB) Viewed 15412 times

When the filament is pressed with hand the extruder works again so it was not clogged.

Please help me with a definitive solution because I'm only wasting material, energy and time.

Best regards.

[Toy]

Seems you need to get a new feeder, you can contact the seller for that.

[Napalm]

Hi,
I am the one who started this thread.

Just wanted to say, that I could not find a solution to my problem. So at last, I exchanged the extruder against a 8 Euro metal Extruder from ebay.
Since then everything works absolutely fine and without any problems.

I should have swapped the extruder earlier instead of spending days of testing and lots of Material

regards
Mirko