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rostock 301 filament extrusion too hard

Posted: Mon Sep 19, 2016 2:40 am
by raoulito9
Hi.
The thing is that my new 301 can push enough filament in extruder to reach a good quality print.
With extruder 0 quality is terrible.
With extruder 1 and 2, it does extrude not even something to print...
I looked at the extrusion motor, and it runs normally, but the wheel skids on filament, because too much strengh is necessary tu send enaugh filament to hed.
I fear my head is not well drilled...
I own another printer, with 1,75 + 0,4 noozzl, and tryed to push filament with my hand, and it's way less difficult...

What could i do ?

Re: rostock 301 filament extrusion too hard

Posted: Mon Sep 19, 2016 11:51 am
by William
Did the filament come out normally when you extrude with your hand?
1.I think you can unplug the white PTFE tube and unclog the nozzle with the ejector pin.
2.Remove the fans on extruder motors to check if the sending filament process is normal.
3.Increase the value to 1.1 in Slicer setting to see how it goes.
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Re: rostock 301 filament extrusion too hard

Posted: Mon Sep 19, 2016 3:41 pm
by raoulito9
Hi.
Thank you for your answer.

I first tried to increase the % of filament feeding. No effect.

I had already removed extruder fans, ant i can see the extruder dent wheel is skidding on filament.
With my hand, the necessary force to push filament is way too excessive.

Head is not clogged but cant let pass enough melt filament...
I used to print around 200 °, and i tryed even with 220 °, does not change anything.

Re: rostock 301 filament extrusion too hard

Posted: Mon Sep 19, 2016 5:31 pm
by William
What you exacly mean?
I had already removed extruder fans, ant i can see the extruder dent wheel is skidding on filament.
With my hand, the necessary force to push filament is way too excessive.
The filament comes out normally with your hand extruding?
Sound like the extruder motor part has no enough driving force,doesn't it?
Could you show me your extruder motors' movement with a video?

Re: rostock 301 filament extrusion too hard

Posted: Mon Sep 19, 2016 5:50 pm
by raoulito9
The filament comes out normally with your hand extruding?
- No, i need to push very very hard to extrude somethinbg.

Sound like the extruder motor part has no enough driving force,doesn't it?
- It has enough force, but the toothed wheel slips on the filament

Could you show me your extruder motors' movement with a video?
- Extruder motor movement is normal, but filament is too hard to push into bowden.

Re: rostock 301 filament extrusion too hard

Posted: Mon Sep 19, 2016 6:07 pm
by William
Unplug the three PTFE tubes and check if they are plugged into metal tubes deep enough.The plugging length should be about 6cm.

Re: rostock 301 filament extrusion too hard

Posted: Thu Sep 22, 2016 5:28 am
by raoulito9
Hi, this is what i've done.
And i followed the entire unclogging process, hoping it would help, the re plugged PTFE, pushing them to max depth.
Nothing new, the toothed wheel slips on the filament, and just a little amount of plastic is extruded. It gets a little better if i help the motor, pushing strongly with hand.
My other printer (1,75/O,4, standard nozzle) does not need that much force to extrude.
Is it normal ?
I fear my diamond head is bad drilled; someone else on this forum had the same issue.

Is it frequent ?
I'm really upset.

Thanks for advices.

Re: rostock 301 filament extrusion too hard

Posted: Thu Sep 22, 2016 5:12 pm
by William
You can make a test like the video shows,so as to check if the feeder system has no sufficient force to push:
https://www.youtube.com/watch?v=m6ax0HsfcNE
BTW,it is true that the filament is so hard to push for bowden extruders,and i experienced it,whose needed force is more than I3 model.

Re: rostock 301 filament extrusion too hard

Posted: Fri Sep 23, 2016 12:33 am
by raoulito9
Hi.

My feeding system seems to have enough torque, i already pushed extruders vref to 0,7v. (stock was 0,55v)
The dent wheel continue to turn, but skids on PLA filament.
In the video you sent, nothing come out the nozzle.
With my printer, I get a small amount of plastic. not enough to print correctly.
I use absolutely standard PLA.
Here is a video of my printer...
https://youtu.be/dhtSmFOUtFs
regards.

Re: rostock 301 filament extrusion too hard

Posted: Fri Sep 23, 2016 11:37 am
by William
You said the gear skids on the filament,did you check if the gap between the philip screw and the gear is too large to push the filament like the following post?
http://www.geeetech.com/forum/viewtopic ... 19&t=17097
And all the 3 extruders have a skiding?
If they do,maybe the nozzle has a clogging or has a problem itself.
Also,what is your "Extrusion multiplier" value in slicer?
Finally,the printing speed in your video is too fast,speed it down to 15-20mm/s to have a try.