When I print an object, the filament is coming out off the nozzle
With short ‘jerks’ it is going in with the motor into the filament tube.
After one or a few layers I feel it is going the wrong way. Smal steps in the tube, bigger steps pull the filament out or isn’t going in at all.
I can press the filament in by relaesing the spring and push the filament in by hand.
Then some filament is coming out of the nozzle.
But it is not coming automatic by motor.
I’ve tried everything but don’t know what to do.
So: first the motor push the filament into the filament tube but after a few layers the motor pulls the filament back
Although the nozzle is ‘printing’ no filament is coming
Check your motor is well mounted witout the filament pulley touching borders. It is easy to mount it in a touching way that does not allow your motor to move correctly.
Else, wich temperature and material are you using to print ?
Your nozzle is probably partially clogged (check here a procedure to clean it).
To print use the following parameters :
Temperature : 190° PLA - 220° ABS
Flow : 75%
Retraction 3 mm - 140mm/s
Infill : no more than 60% (usually 30-35% is enough).
I think the motor is mounted good. Because first it pushes the filament into the tube to the nozzle. But after few layers it pulls it out of the tube and away from the nozzle.
So the nozzle don’t get any filament.
When I release the spring by the tube and push the filament in by hand, then the filament comes out of the nozzle.
So the motor pulls the filament after a few layer printing away from the nozzle. Nozzle works fine.
Can it be a software problem?
I work with PLA at 210 degrees. First layers seems fine wen there is coming filament out of the nozzle
[quote=“dione770”]I work with PLA at 210 degrees[/quote]This temperature is too high and it will burn the filament inside the nozzle (thin layer of burned filament on the inside walls narrowing the passage and preventing a correct extrusion).
make sure the pulley on the motor is mounted as shown in the manual or as you can see in this picture. Take a look at the orientation (me myself mounted it wrong the first time without noticing)
The ribbed groove needs to be on top and not on the bottom, if it is on the bottem the motor will have a hard time trying to get the filament in the tube/printhead.
I don’t now which trials you already made, and with which success. To my understanding I would summaries your problem in this kind:
the motor is able to push the filament (at least at the beginning)
At the beginning of the extruding is fine
after a short time the filament is snapping back at the extrusion block entry.
I have met this situations several times during my different tests, this is mostly happening at a forward step of the extrusion motor. In fact, it is not a step back of the motor, but a slip in the pulley.
This means in a first consequence, that the pressure in the nozzle cannot be released as expected. This can have several reasons:
Temperature too hot: the effect as described above may appear, but: a burning of the material will preferentially take place during the heat up phase, where we get an overshoot of the temperature control. Residues of burnt materials will be abraded during printing, it will pass the nozzle (no problem) or will block it. In the lattter case the nozzle will be completely blocked without a chance to push the PLA by hand.
Furthermore, the PLA temperature setting is like a rule of thumb, since for the original configuration the temperature reading is not reproducible enough. Possible print temperatures are varying for different material suppliers, I succesfully printed with 215°C PLA. => unlikely.
Retraction length too high: PLA will stuck in the middle of the nozzle, even by hand it is impossible to push forward. => unlikely
Extrusion rate too high: after a few layers the re is no free space between nozzle and top layer of the printed object because everything is filled with excess material from the former layers. Then the nozzle is blocked (no gap left to fill). In this case you are still able to push the filament by hand => MOST LIKELY.
To verify this please check the following settings:
Firmware v1.4 installed without changes (original version from Vellemann repositories)
Extrusion factor approx. 1
In this case you will end up in condition 3.
However, in the original configuration the extrusion motor has to work against the pressure in the nozzle and the friction in the filament guide. In the original parts the filament doesn’t go through in a straight line but is bended outwards. By this design it is heavily rubbing at the sidewalls of the guide holes. This can be enforced by small dislocations of the pulley. So a part of the motor force is waisted in the folder itself, reducing the force for extruding.
Finally, there are several possible reasons for your problems, which may act in conjunction. It’sa a little bit like detective work to find out the reason.
I discover another reason why the fillament-motor stops. When you are printing from SD and during this process you switch on the connection between Repertier and the Vertex. Everything is going wel except the feeding of your fillament.
Thank you all for your replies.
Although I thought I mounted the the pulley on the motor well, it seems there was the problem.
I marked the pully and it rotated good for several degrees. Then it stucked at always the same place (at the same angle).
I rebuild the unit for the filament extruder and now it is working good.
Thanks for all your suggestions. It really was very helpfull. I learned a lott.
