Struggling with ABS

This is for general discussions. Also FAQ can be found here.

Moderator: speedake95

Post Reply
Hugues
Posts: 270
Joined: Thu Apr 04, 2013 5:36 pm

Struggling with ABS

Post by Hugues »

Hi guys,


i received my roll of ABS yesterday so most of the day today i tried to print but it's pretty difficult to get a good print so far.

I 'm heating the extruder at 240, tried 235 also, bed at 85 (i cannot go much higher, 88 maybe), then went down to 75 also. I tried printing on glass sheet with a little mix of white glue and water, but ABS does not hold up to this. Then tried adding large brims around my part, a little better but still warping. I bought some blue tape from Tesa, and still used brims, less warping at the base now, but still , the upper layers are really not straight.

Anyone got successful prints with ABS so far ? Care to share your "recipe" ?
Hugues
Regards from Switzerland

Sündi
Posts: 16
Joined: Fri Oct 12, 2012 7:32 pm

Post by Sündi »

I print with ABS, but I made a PCB heatetd bed and print with 235-240°C and 90-100°C bed. I use a glass sheet with kapton tape and for larger prints with ABS Aceton mix. I think the 100°C are important because the ABS is getting soft above 100°C. I heard about printing on plexiglas maybe with the lower temperatures you get good results (I never tried this yet)

killejano
Posts: 92
Joined: Mon Apr 01, 2013 7:23 pm

Post by killejano »

Abs glue seems to work ok. Don't even have to heat the bed much. I've been using it straight on the aluminium now. I tried on kapton, but it held so tight the warping part pulled the kaptor of the table. It ried plexiglas and it might be good. Mine was just too thin so it warped when heated.

superhornet59
Posts: 60
Joined: Wed Apr 03, 2013 1:58 am

Post by superhornet59 »

I use blue painters tape for both ABS and PLA and the only time I've ever had adhesion problems were after doing something that messed up my bed calibration. Otherwise, it's flawless. Don't forget that for any combination, starting out a little hotter, a lot slower, and at a larger layer height (.25mm) tends to help. If your part has a small base, consider using a raft, it really does help.

If you're having problems with the part warping mid-print, lower your fan speed settings. PLA and ABS are much different, PLA comes out near-liquid and hardens almost instantly with a bit of cooling. ABS comes out sort of play-doh like and just settles right into place. Make sure your fan isn't stuck on 100% or something, ABS doesn't like that. If you have drafts around the house, you can try creating a 'thermal barrier' as well by creating a brim 5-6mm from the part and only 1-2 perimeters thick, with the same height as the object. This barrier will prevent cold drafts from causing uneven cooling. And yes, the extruder fan is also a form of uneven cooling. Cheers!

Hugues
Posts: 270
Joined: Thu Apr 04, 2013 5:36 pm

Post by Hugues »

ok guys, thanks for your input, there is some progress, here i what i've tried:

- turned the fan down to zero, it was running at 100%, thought it was like PLA
- increased bed temp to 90 C
- made some acetone glue

i tried first to put the glue on blue tape, cause i feared i could break my 2mm glass sheet if the part sticks too much. I had this problem last week with white glue. The part came out with some warping, but mostly because the tape did not stick to the glass that well. :roll:

So now i tried to put the glue directly onto the glass, first 21 layers out of 91 show no sign of warping :)
let's see how it's gonna come out.

Edit 15:55: The part is warping !! :shock: I did not see it at first because i could not see any play between bottom of part and bed, but there is. There is a thin film of glue i guess that has lifted from the bed. Maybe my mixture does not have the right qty of ABS ?

Question: what's the easiest way to remove the part from the glass when the print is finished ?, without risking of breaking the glass sheet. Should i let it cool down completely ? Or should i try to remove it when it's still warm ?

P.S: had some delamination problem on the first part, so i increased the temp from 235 to 240, then flow rate from 70 to 90. We'll see.
Hugues
Regards from Switzerland

Hugues
Posts: 270
Joined: Thu Apr 04, 2013 5:36 pm

Post by Hugues »

So here's a picture of the problem i'm describing in my post above.

I used Acetone glue on my 2mm glass sheet, 90 C, and the part managed to peel the layer of acetone glue from the sheet when warping.

Could it be that my acetone glue mix is too thin ? should i use more ABS into the acetone ?

The part was very easy to remove, no adherence really, and i also removed the rest of the acetone glue film very easily.

Or maybe i should also use a brim ?

i'm not sure i've seen this kind of issue described anywhere....
peeling.jpg
Hugues
Regards from Switzerland

superhornet59
Posts: 60
Joined: Wed Apr 03, 2013 1:58 am

Post by superhornet59 »

Wow, that is an unreal amount of warp! Quick question, looks like you're printing a sort of beam. Are you using your Felix for prototyping (like I am) or mostly making cute little trinkets? If the former, I should tell you that the warping of ABS will be a problem even if it does stick to the bed because nothing will be dimensionally accurate anyway, especially for larger parts. If there is a choice, switch to PLA, I have found it to be pretty good in the accuracy department.

As for sticking to the bed, go with blue painters tape, and just be cautious when removing. Try using something sharp like a knife (a kitchen knife - a hobby knife/exacto knife blade is too thin and will snap) and pry it off. Just dig the tip in a little under the part and maintain steady upward pressure, you'll hear it coming off almost like velcro. That way it sort of 'peels' off instead of having to be 'ripped' off, which should keep your glass plate safe. I've got a 3mm glass bed, and it's never hinted at cracking. Also, chances are the blade will cut the painters tape and you'll have to put new tape down for each part, but, C'est la vie.

Hugues
Posts: 270
Joined: Thu Apr 04, 2013 5:36 pm

Post by Hugues »

The part above is to repair an outdoor chair, precision is not critical.
But i intend to make parts for my motorbike, i like the look of ABS after bathing in acetone vapor.

PLA is easier to work with, but does not seem as solid, and the finish is average. And not sure how long PLA would last on my bike under the sun and rain.

I've read in another forum some are using a mix of water and white glue for ABS. I tried it for PLA and it was extremely sticky, so much that i broke my glass. I think i'l try it with ABS, but a ration of 10:1 to make sure i can take the part out .
Hugues
Regards from Switzerland

Post Reply