ABS sticking to extruder
September 09, 2015 04:00AM
Hi, I have a prusa I3B printer and when I print the abs plastic curls up and sticks to the nozzle. What should I do? I have tried changing the nozzle temp from one extreme to another but it doesn't seem to help.
Re: ABS sticking to extruder
September 09, 2015 06:46AM
What surface are you printing on?
Re: ABS sticking to extruder
September 09, 2015 01:43PM
Hi,

Don't try to jump as fast as that from extreme values.
If you want to calibrate temperature to match your filament need, print a calibration tower.

BUT I believe your problem is not due to extrusion temperature.
Check first the bed adhesion and then do a proper extruder calibration.

++JM
Re: ABS sticking to extruder
September 09, 2015 04:14PM
Quote
AlexY
What surface are you printing on?

Borosilicate glass with hairspray on it.
Re: ABS sticking to extruder
September 09, 2015 04:21PM
Quote
J-Max
Hi,

Don't try to jump as fast as that from extreme values.
If you want to calibrate temperature to match your filament need, print a calibration tower.

BUT I believe your problem is not due to extrusion temperature.
Check first the bed adhesion and then do a proper extruder calibration.

++JM

When it prints close to the bed the plastic comes out in small blobs so I don't think I can print. The higher the z axis gets the smoother it runs.

Edited 1 time(s). Last edit at 09/10/2015 02:57AM by SkeptikRC.
Re: ABS sticking to extruder
September 09, 2015 04:24PM
What temperature is the bed heated to? For ABS I think it should be around 110ºC.
Re: ABS sticking to extruder
September 09, 2015 04:50PM
Hi,

If you have some blobs, it's maybe over extrusion.
Did you set-up your extruder's preferences properly ?

++JM
Re: ABS sticking to extruder
September 10, 2015 02:57AM
Quote
AlexY
What temperature is the bed heated to? For ABS I think it should be around 110ºC.

Yep, 110 celsius.
Re: ABS sticking to extruder
September 11, 2015 06:01PM
110 seems a bit high. I print abs without problems at 85C bed.

But if your nozzle is hot enough to melt and extrude the abs, and you have curling up and clumping on to the nozzle, I would think that either your nozzle is too close to the bed and the abs can't get out the nozzle easily, or it is correct and the abs is not sticking to the bed.

Try dropping the temp to 85C bed and try this alternative method - no spray / slurry / glue, etc https://www.3dhubs.com/talk/thread/alternate-print-surface-abs-no-slurry

Due to the nature of PVC, ensure you have good ventilation.
Re: ABS sticking to extruder
September 12, 2015 12:30AM
Hey there, I was having a similar problem when I first set up, this worked for me:

first I calibrated my extruder with help from this video

[www.youtube.com]


then i figured out my optimal adhesive combination

bed heat from 85-100 anywhere in that range works for me

and a glue stick from the dollar store, I just clean off my bed with a razor blade every 2nd or 3rd print


Hope this helps =]

Edited 1 time(s). Last edit at 09/12/2015 12:32AM by straton jd.
Re: ABS sticking to extruder
September 12, 2015 08:16AM
Hi,
Quote
DaveOB
110 seems a bit high. I print abs without problems at 85C bed.
The bed must be set close to the glass transition temperature of the material.
At glass transition temperature, the material is flexible but keeps its shape.

Glass temperature :
ABS +-105°C
PLA +-63°C

So 110°C is a bit high, but 85°C is realy too low.
With a bed at glass transition temperature, don't cool the part too much with ABS,
or you'll experience wraping even with a proper bed temperature.
I would say cooling fans to 30-50% maximum.
So minimize bridges on your parts.

++JM
Re: ABS sticking to extruder
September 12, 2015 08:40AM
Quote
J-Max
So 110°C is a bit high, but 85°C is realy too low.
With a bed at glass transition temperature, don't cool the part too much with ABS,
or you'll experience wraping even with a proper bed temperature.
I would say cooling fans to 30-50% maximum.
So minimize bridges on your parts.
++JM

OK. I suppose different things work for different people.

I have been running 85C bed for ABS for over a month and never had a print lift or warp.

Also the reading I have done says you should not be using a print cooling fan for ABS. Maybe that's why you're having to go up to 105 to counter the cooling you shouldn't be doing ?

Also I use an aluminium bed, but with the plastic cover, it shouldn't make any difference if it is glass or aluminium.
Re: ABS sticking to extruder
September 12, 2015 11:53AM
Hi,

A month is a too short period of time to make any universal rule. winking smiley

To set your bed ways under the glass transition temperature
only means the early layers are not stretchable any more.
We use heating bed because we want the first layers to stay flexible.
Through, maybe 85°C allows a good bound on your print surface.
But these are two different things.

Like you, I don't use cooling fans with ABS.
But bridges and overhangs can't be very clean.
Each material have its own properties.

++JM
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