ABS warping

I'm just looking for some ideas here. Since I got an all metal hotend (the Pico), I've been printing ABS. I had some early jams with PLA and decided I wanted to print things that wouldn't melt in the sun anyway, so I switched to ABS. Printing is now easy, except my printer didn't come with a heated bed so I am of course experiencing warping. I'd like to know of any ideas people have tried that may not be among the commonly described methods to prevent warping.

First off, I'd prefer not to use messy methods requiring constant resupply, like hairspray or tape. Secondly, is heating critical, or is it purely an issue with adhesion? My printer has an acrylic bed and the ABS sticks to it pretty well, but I'm guessing it would be a bad idea to heat it. Is that true? I've heard ABS doesn't stick to glass well unless you take additional measures. What about frosted (slightly textured) glass? Metal? Exotic materials? Does printing faster or slower affect the amount of warping? Are there other factors?

Thanks

Printing ABS without a heated bed is nearly impossible, i would not recommend heating a acrylic bed.
The main factor of warping is your part cooling off to fast.
I myself only have no warping when using heatbed at 100°, mirror covered with kapton tape and sprayed with abs juice and even then it sometimes goes wrong.
That is why i only print PLA anymore....

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Prusa I3 kits www.schufco.com

"Printing ABS without a heated bed is nearly impossible"

That's clearly not true. I have no problem printing things and they adhere quite nicely to the cold acrylic bed, but they do tend to warp at the corners. I've seen mention of printing "rafts" under a print but do not understand the details or if they are at all useful in this situation. It is interesting that only the bottom warps, which would imply that printing extra material at the bottom would help reduce warping.

"That's clearly not true. I have no problem printing things and they adhere quite nicely to the cold acrylic bed, but they do tend to warp at the corners."

Of course you can print abs on an unheated bed, but the question was how to print abs without warping.
You can always use raft layers or brim to reduce warping, but eliminate it...?

" It is interesting that only the bottom warps, which would imply that printing extra material at the bottom would help reduce warping."

The abs touching your "cold" print surface is causing the part to cool to fast which is the cause of warping.

Edited 3 time(s). Last edit at 10/29/2014 07:25PM by Schufco.

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Prusa I3 kits www.schufco.com

For little printed parts, I would encourage you to give a try at printing on a garolite plate. It's only worth a few bucks, so not too expensive to test out.

ABS sticks very well onto it, without adding anything else, so you might be able to print some reasonably sized things without warping.

I am using it with success even for large ABS parts, but I am heating the bed so i cannot guarantee the result for you.


My source was on amazon, but feel free to look around for better deals : [www.amazon.com]

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Most of my technical comments should be correct, but is THIS one ?
Anyway, as a rule of thumb, always double check what people write.

Thanks DeuxVis,

I am not against heating the bed, I only wanted to know if it was truly necessary. I am considering heating a 1/8 inch thick aluminum plate as they are pretty cheap to source, but I wasn't sure how well the ABS would stick to it.

Question: How does surface roughness affect adhesion? Is it better to have something polished, or rougher?

Since ABS seems to stick to acrylic so well, what about a high-temperature acrylic? I'm pretty sure such a thing exists. Has anyone tried graphite, or carbon fiber, or ceramic?