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Anyone familliar with this "bubbling" problem?

Posted by gm2 
gm2
Anyone familliar with this "bubbling" problem?
November 20, 2013 11:45AM
It looks to me like hot air is forcing it's way out of the infill pockets when the printer does the cap layers and thus bubbling out the plastic. This is with Monoprice Black ABS... Best I can recall it was 15% infill printed at 230c with the bed at 110c. Any ideas on how to fix this? I am also having quite a few pop-offs and curls that may or may not be related. For that I've tried extra good cleaning the glass, hair spray, kapton tape, etc but nothing yet seems to be a great solution. These issues are only with ABS. PLA prints amazingly well.
Attachments:
open | download - IMG_20131120_113027.jpg (115.3 KB)
Re: Anyone familliar with this "bubbling" problem?
November 20, 2013 12:04PM
couple of questions,

have you calibrated your EE steps for the ABS?
what slicer you using/speeds?

but for the popping off ive been there, i use kapton tape cleaned thoroughly with acetone(pure) and if that still doesn't work dissolve a very small amount of abs in acetone and spread it as evenly as possible ontop of the kapton, very thin layer should stick very well....might be hard to get it off.
Re: Anyone familliar with this "bubbling" problem?
November 20, 2013 12:51PM
I don't think it is anything to do with air. It looks like maybe you don't have enough solid layers over sparse infill or are stretching the plastic too thin to bridge gaps.


[www.hydraraptor.blogspot.com]
gm2
Re: Anyone familliar with this "bubbling" problem?
November 20, 2013 01:15PM
.1mm layer heights.

I calibrated the EE steps during the initial calibration of the machine with PLA. Will this vary with ABS? I hadn't thought about that being a potential cause.
Cura slicer - 50mm/s perimiters - 80mm/s infil

I was worried that acetone might disolve the kapton. I'll try some acetone now also for the pop offs.

The only reason I thought it might be air is that the bubbles are domed up. I'll try a thicker shell and less infill

Thanks for the help! Any more suggestions are welcome.
Re: Anyone familliar with this "bubbling" problem?
November 20, 2013 01:31PM
dont reduce the infill, increase the top and bottom layer number this will give it better support on top, i usually get my slices to have a specific shell thickness on each slice, so if you want it to be 0.5 mm thick shell at the top you need atleast 5 layers at 0.1mm layer height etc.

you need to recalibrate with different filaments as they will differ in stiffness meaning that the pinch wheel grips it deeper especially on abs, effectively reducing the overall pinch wheel diameter, if makes sense?
i doubt it will solve your issue but from the image it looks as if it could improve it a tadge as the top seems to be laying down too much plastic.

the acetone wont harm the kapton in the slightest so dont worry about that at all.
gm2
Re: Anyone familliar with this "bubbling" problem?
November 20, 2013 04:10PM
great info on the EE steps. I wouldn't have thought of that. Thanks!
Re: Anyone familliar with this "bubbling" problem?
November 21, 2013 05:35PM
has your issue been resolved?
gm2
Re: Anyone familliar with this "bubbling" problem?
December 06, 2013 09:47AM
The bubbling issue seems to have been corrected by adding additional shells to the top.

I'm still getting quite a bit of curl on the corners of parts (only abs) though. I've tried kapton, cleaned with abs, abs juice, and hair spray. Some of these make the part stick really well and require quite a bit of prying to remove... but the corners still lift. I've even got an enclosure on the front to prevent drafts.

I'm using Monoprice 3mm black ABS, and i've measured anywhere from 2.87-3.05 on the thickness. Could the highly inaccurate material be a substantial part of the problem?
Attachments:
open | download - 2013-12-06 09.35.52.jpg (116.1 KB)
Re: Anyone familliar with this "bubbling" problem?
December 06, 2013 09:59AM
Thats quite bad. What temperatures are you using for your bed and hot end?

I find with kapton and a very small layer of abs juice I have to put alot of force to get them off, (started designing with a hole to pry from without damage).

Also check your z height is as close as you can to ideal, I had issues with curling when the hotend was off by 0.05mm. If its slighty too close it will stick more but it will obviously be less accurate
gm2
Re: Anyone familliar with this "bubbling" problem?
December 06, 2013 10:18AM
I am using the default M90 temp settings included by Nophead. 240/130

I've been calibrating the the z-height based on the thickness of the perimeter print. It changed a bit when I first installed the kapton tape but I reset it and it's consistently within .02. The bed level has also been set with a dial indicator to be within a few thousandths across all 4 corners.
Re: Anyone familliar with this "bubbling" problem?
December 06, 2013 11:00AM
If it was me id first try the temperatures, nopheads are generally sound but depending on the colour/supplier required temperature changes, for example with my blue abs I use 245/120(110after first layer).

If you turn on the printer and set the hot end temp to 240 let it settle then try turning the extruder wheel manually, if its quite difficult up the temp if it oozes out of the nozzle excessively it needs to go down. Just as nophead says in the manual maximum safe temp is 250 so be careful.

The in consistency lf the filament I carnt see as being the reason here, unless it is causing non uniform stresses within the part causing it to curl.

Although the inconsistency of the filament does seems to be quite high id recommend using a different supplier to get consist print quality (nophead informed me a while back of a company called reprap source the delivery charge is higher as its from europe but the quality is superb). Something that I found when I brought filament with sush inconsistency Is that if i snapped it it has air bubbles along its length in the middle (usually with abs) which I found was because it was actually abs welding filament not reprap filament as it didnt need consistency.
Re: Anyone familliar with this "bubbling" problem?
December 06, 2013 11:05AM
I have been printing very successfully with ABS on glass coated with the cheapest extra-hold hairspray I can find. Two coats.

My nozzle is .35 and I generally print at .25 layer height. I have; however, successfully gone down to .1.

I use the latest Slic3r. I set my bottom layer height also to .25, but in Slic3r I can cause the bottom layer to overextrude to really stick it down. I set the bottom layer to 125%.

I run my bed at 110 C.

When I am done with prints I set the glass on the counter and as it cools the parts pop right off.

I have attached a picture of a sample .1 print I did. On the right is a sample print they send you if you ask for info from Stratasys. On the left is my bottle. The Stratasys rep sent me the bottle .stl so I could compare apples to apples.
Attachments:
open | download - Bottles.jpg (134.2 KB)
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