I have been printing for a while now, but suddenly it retracts unwanted after a few minutes of printing. the settings has been the same for a while so it couldn’t not be that, but I don’t no what to do. I am printing in 0.2mm. i had the same problem in the beginning of printing, but it got solved with the right settings. I have checked the G code and it shows not any retraction at the time it do so.
I have tried some different things now:
Upgraded vertex software to vertex-m1-v1.4-h1, no change.
Changed the stepper motor driver for the extruder, no change.
Changed different settings for ABS, to 235 deg., lower speed and new G code settings as described some place in here, no change.
The last thing i did try was lifting the lever at the extruder to see if the stepper motor kept turning without any retracting, and it did.
So it has nothing to do with the software or defect hardware, but what is it then?
I did try to change the Ve-jerk values, but nothing else happens here.
As i see it, it can’t keep up the filament pressure for even short time, before it retracts it.
Has anyone experienced any things like it, please tell me :).
many thangs to all the good stuff in here
best regards Jan
If the extruder is making a clicking noise, moving slightly backwards again and again, it means you have a (partially) clogged nozzle.
Thanks for the reply :).
I cleaned the nozzle, and tried again but after 50 minutes it began again 
How can the nozzle even get clogged, are there any spaces where it kan get to.
In the nozzle it cant be, because it is heated and therfore it can get pressed out, it must be before.
Everything is tightened so it cant either be it.
To answer to your question I need to know some of your settings :
Are you printing PLA or ABS? At which temperature and flow? What are your retraction parameters?
The cause of the clogging can be twofold :
- the filament is too hot and soften before the nozzle, making a tiny blob blocking it.
- burnt filament coats the inner wall of the nozzle narrowing the passage.
I’m using ABS at 235deg. to 240deg. 54% flow in cura, which i don’t understand has to be so low, but i get great results when it’s printing without errors at that flowrate.
I made an heated bed and it’s set to 90deg.
As you said it was clogged up, but it will be worse with in the time because of the PTFE tube used.
The PTFE tube is pressed a little bit, so it leaves a little space where the filament can leave a small ‘“blob” so it gets stuck and cant unload.
(I used a’ caliper with a resolution at 0.05mm to measure the length of the PTFE tube, so i now it’s the correct length.)
I have some pictures to show, but i can’t see how to send them to you.
I have a’ Desktop Mini Mill, where i will make a small tube in aluminum, and i will send my experience with it, and also the dimensions and pictures if you are interested.
I’m aware of that the heat from the nozzle not must heat up the aluminum tube, so that i will take in to account in my design.
I will come with some results within a week, ill think.
best regards Jan
I’m printing ABS at 225° (more and problems are beginning …) with a flow between 75 and 80% (depends on the color of the filament). I use 3 mm retraction at 140mm/s.
My heated bed is set at 90° too.
[quote=“8660jan”]As you said it was clogged up, but it will be worse with in the time because of the PTFE tube used.[/quote]Not necessarily. If the filament doesn’t soften above the nozzle it won’t happen (that’s why IMO your flow is too low and is increasing the risk of softening).
[quote=“8660jan”]I’m aware of that the heat from the nozzle not must heat up the aluminum tube, so that i will take in to account in my design.[/quote]I’m looking forward seeing how you’ll solve this.
To insert pictures you’ll have to host them somewhere (A dropbox will do) and then insert the link with the Img tag.
If i use flow at much more than 54%, the nozzle will push the already printed filament and therefore also the bed around, and the result is bad.
(I use infill overlap at 15% in cura)
Hello. Now I have fixed my problems by making some new parts to the hot end.
You can see how the old parts was after about 20 hours printing by 240 degree
With the new parts, i have printed for about 40 hours, and some of the print was done by 245 degree and no problems :).
I have added an aluminum plate to control the airflow to the hot end. Before i did that i had some problems to reach
much higher temperature than 240 degree.
I have also drilled through the sides of the hot end so the airflow can blow through it
And an comment to the temperature for this printer spec. 270 degree, this is for only very short times, because PTFE Teflon and
Peek is for max 260 degree. There is some materials (polyimid) there can withstand 300 degree, but it is very expensive
I used Peek in my new design, instead of PTFE.
Se My Pictures Bellow
dropbox.com/sc/0axb4ely21q5 … sC2Yl1fl_a
Have a nice day :).
Regards Jan Holm