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Getting extreme blistering on each print
#1
I had successfully printed a few small parts and the quality was acceptable. See this picture.



However I now am trying to print a larger print as a test of larger print and layer 1 is blistering very very badly.



This is repeatable on three different ABS fillaments which I've used before for smaller prints with no problems.

I also found an issue with the glass bed, it was just sliding around about 2mm to either side inside the carriage. I fixed that by adding a couple of layers of foil underneath the insulator pad on all corners., now the bed doesn't move, but I still get these large print defects that are rendering my efforts useless.[Image: IMG_20141129_222136947.jpg][Image: 20141209_171004.jpg]
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#2
Hard to diagnose without temps used. Please also specify whether you are on stock or custom firmware, as remediation instructions/feedback will differ. For example, I print ABS @ 230/90 extruder/bed, luc's .92 firmware, variety of filament manufacturers and have never seen this even on $15 per kilo spools. Is the shine and flakes from ABS slurry? Are the perforated lines part of the defect or design?
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#3
luc's 0.91, shine from glue stick.

Bed temps tried from 110 through 130 same result, extruder temp from 210 to 230 same result.

The successful print was using 110 bed 230 extruder temp. Tried same ABS reel - same result with blistering.

The perforated garbage is part of print defect, not a design.
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#4
Eugene,

Are you printing ABS at that high of bed temp to avoid warping/curling? If so, higher temps make it worse from what Ive seen. Bump the bed down to 90 and print with a brim to keep it adhered to the bed. Maybe for short runs bed that high is fine, but starts melting over time.
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#5
Was doing that since I was having issues with sticking to bed even with glue stick or hair spray. The brim ended up curling up on contact with bed and on layer 2 getting stuck on the extruder and just messing up the whole layer 1 of the print. Hence I decided not to do that.
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#6
Eugene,

I hear ya, bed adhesion was the main reason I went to custom firmware. I have pretty good success with ABS slurry applied with a crumpled up paper towel, and 2mm brim @ 90 degrees bed. Things Ive observed not to correct bed adhesion is higher temps, more glue, and extruder offset closer to the bed. You may end up having to tweak bed temps based on the model being printed. If the brim isnt even sticking to the bed you have may have Z home set too far from the bed. In slic3r, i have no extruder offset defined for ABS, and my extruder/bed distance is just enough for a piece of printer/copy paper to pass under. I hope this helps, but honestly I experience this frustration everytime I switch over to ABS on this printer. With bed temps that high I could see this happening if filament has any moisture inside, versus the usual layer blobs/bubbles.
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#7
I went with custom because of my problems with the supplied filament cartridge. It was pure garbage and printed with lots of "artifacts". This no name chinese filament is so much better. I want to get quality filament, but shipping anything into this country is a pain in the rear. I'll try your suggestions and will check the z-offset. I just got done re-adjusting my bed after I got done modifying it. That sliding glass sure caused a lot of frustration. Now I'm finding that the bushings on Z on the right side are completely unsuppoted and just wiggle in there. Same goes for Y and X on the side that is not supported around the bushing. This will require more work...
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#8
Ok, I tried to print a 2mm brim and lower the temp to 90 on the bed. I am still getting mild blistering and quite a lot of lift. ABS slurry isn't an option at this point - it's winter and the smell won't vent well. Goint to try a bunch of test pieces tomorrow to see if I can find the perfect settings. Fixing the bed helped print quality a lot though. No more "ladders".
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#9
I doubt it will help but I did notice that applying glue to an already warmed bed wasnt as successful as applying it to a completely cold bed. I have even gone as far stopping a print and super gluing a corner down when it would start to lift.

I put little shims from a credit card in between the bed glass and the frame to stop the shifting. While my bed still wobbles at the bushings, fine tuning print settings helped a ton so that I wasnt dragging the extruder against a dried layer and pulling the bed back and forth. But this is admittedly a fine line between proper bed adhesion and proper extruder clearance.

Something worth noting that helped me out with adhesion.....I noticed that when the extruder init strip (u may not even have this in your code) had a rounded top, versus a flat ribbon, I would get lift even though the bed was supposedly tuned. I know thats common sense, but thats an area that often escapes me when Im frustrated by an issue, so I thought Id mention. If I raised the bed to get flat ribbon for the extruder init or skirt, the brim and first several layers were usually ok and stayed stuck to the bed. If you find a combination that works consistently, please let us know. Im dreading the day a project mandates I load ABS up again.
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#10
Gentlemen,

I am reporting back and I have found what the issue was for me. It's rather a combination of issues.

1. My bed modification to stop the glass from sliding around for sure affected the auto-leveling functionality. I think the auto leveling stinks anyway, I use the paper method and I have ordered an indicator that I'll use for future calibrations. I also found a very good method to calibrate with no paper that produces accurate results. Goes something like this: i) loosen the bed screw on the right until the extruder start catching on side of glass right on top of thumb screw, lower just enough for it to clear, ii) repeat on the left. iii) move extruder to the right and in line with front thumb screw, repeat the glass catching, do on the other side to make sure it's fine. When flashing a light at the extruder tip you should see the clearance and it must be uniform everywhere on the bed. I found this method better for myself. In EEPROM I set z-min to 0.

2. Why in the world setting Slic3r first layer to 0.4 is a good idea I don't know. I looked through g-code and I found no provision for ADDING MORE PLASTIC on layer 1, only the increased gap. This was the source of my prints not sticking. I changed layer 1 thickness to .15 and it produced much better results immediately.

3. I had to adjust the filament feed rate to 1.05. That's not a significant increase, but it made my prints looks a lot better.

Now I have to fix the Z carriage slop and than I think I will be done.
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