Issues with printing ABS

I have recently started getting really bad air bubbles in my prints. I am using a Lulzbot Taz4 with matter control and curaengine to slice. It is only printing the air bubbles in certain places in the print and I can’t seem to figure out why it is doing it. See the pics below. Thanks for all suggestions and help in advance.

Howdy!

Aw, bummer on your prints being difficult! I’m still pretty new to printing, though I’ve had issues and I’m still learning myself!

It could be a combination of things. What kind of ABS filament are you using(who makes it)? I’ve seen other people running into issues like this because of contaminated plastics or excess moisture can cause these voids. It’s like a mini tea kettle, the moisture hits the extruder, makes a tiny plastic bubbles and the bursts, leaving a void or blob where the filament should be.

If the plastic is form a reputable place, have you left the filament out in a humid enviornment? ABS likes to take in any surrounding moisture. I run into this a bit since I live in a humid climate.

Hope this gives you a starting point. And good luck!

Here’s an article that could help as well :slight_smile:
http://www.tweaktown.com/articles/6174/3d-printing-tips-and-tricks-filament-quality-and-why-it-matters/index.html

We’ve bought all of our filament from Lulzbot so I would hope it’s good stuff. The white is the one we see most issues from. I just printed with new red filament and it worked great. Maybe the white is contaminated?

This isn’t the only print that has had this issue though. It happens on all of the prints in the same place. Could it be a printer setting or something when it was sliced?

Thanks for the response.

Your filliament width settign may be off. measure the actual diameter of the filliament with calipers, then adjust the fillament diameter setting to match and see if that helps. Your spring tension may also be off a bit, try tightening it a couple of knob quarter turns and see if that helps.

Those pictures look like your speeds are too high for your perimeters.

What speeds and layer heights are you using?

White PLA and maybe even white ABS requires a higher extrusion temperature. Try printing at 235 to see how that improves things when printing with white ABS.

I adjusted the temp to 235 and slowed the print speed down some. I hope that will help.

Thanks for the suggestions.

Well the extruder temp and speed adjustment didn’t help with the print. It is still coming out inconsistent. We have a Lulzbot Taz3 as well that is printing on standard medium settings that is printing out just fine when our Taz4 on the same settings isn’t printing out well. The plastic isn’t an issue as the Taz3 printed the white plastic just fine.

Mind posting the gcode file you are printing?

How do I get a text version of the code? I am using Slic3r to generate my gcode. It is the same code on both printers as well so I don’t know why the older Taz3 is printing better than the new Taz4.

open the *.gcode file with notepad is one option.

This looks like moisture in your filament to me. Keep your filament in a zip lock bag with a desiccant when not in use. I recommend Drierite industrial desiccant. I prefer the indicating type. You can keep it in a pill bottle with small holes drilled in the lid and bottom.

Mesh is the number of grains per inch. I would look at 6 or 8 mesh.

You can find Drierite here:

https://secure.drierite.com/catalog3/page4a.cfm
https://secure.drierite.com/catalog3/page4b.cfm
https://secure.drierite.com/catalog3/page16.cfm

I was seeing something similar (using the same filament) and I heard little “pops” once in awhile. When I switched to a different filament (another type for another print)I noticed that the filament was being gouged by having the screws too tight. I lighted the tension so this wouldn’t happen but still allow it to feed. So far, no pops and no bubbles.

My theory is that the gouges were inducing air pockets into the heat chamber.