3D printing with ABS: Hotter nozzle or hotter ambient? #Filaween

You should probably be using a heated or enclosed chamber for ABS.

Let’s talk about ABS.

So after the Filaween episode on the Innofil3D ABS, i got of ton of comments, some questioning my sanity, essentially, because i pointed out a flaw with ABS, which is that layer adhesion basically disappears if you don’t use an actively heated build chamber or even just an enclosure of an kind – and I had deliberately made that choice, because, let’s face it, at least 99% of all printers out there don’t have a fully enclosed build chamber, let alone one that has an active heater in there. In fact, none of the printers i own and only a single machine capable of printing ABS that’s ever been in this workshop was enclosed, and that was the CEL Robox.

So while Filaween is supposed to be a series about typical, real-world performance of these materials, and not lab-grade tests and perfect-world conditions, almost every single material still has that same tradeoff – either you print cold, that is with a lower hotend temperature, in a colder environment or use a stronger part cooling fan, or you print hot and crank the temperatures up so high that you end up with a super solidly fused brick that looks nothing like the original part you wanted. Well, where you want your parts to end up on that scale is totally up to you, but i try to test somewhere in the middle ground temperature-wise where you get parts that remain mechanically accurate and usable, but still get good strength. But of course, that will vary depending on what the part you’re printing is being used for.

So i ran a few more tests on the Innofil3D natural ABS. I bumped up the temperature to 240°C, as you all suggested, though i’d personally have lowered the temperature for all the curling i was already seeing. Then i re-ran the strength tests in open air, in an enclosed chamber and in the enclosed chamber with the part cooling fan at a fixed 20% setting. Now, the “chamber” I’m using here is just the shipping crate the Dynamo3D OnePro came in, and with the printer’s heated bed going and the cracks sealed off as good a i can, it reaches 32 to 35°C in there, which, as you’ll see, already has quite an impact. If you don’t want to commit to building a chamber around your 3D printer, you could also just grab a trashbag or two and plop that over your printer, that should already be enough to have it heat up to where ABS will work much, much better.

Now, of course, this doesn’t just apply to ABS, i’ve also A-B tested rigid.ink’s ASA, which, as you can see, also profits greatly from that extra ambient temperature, and other filaments like HIPS, Taulman’s 910 and PC-ABS also benefit from an exclosure.
So let’s look at the strength numbers: As expected, the higher temperature by itself as well as when combined with the enclosure make this ABS a great deal stronger, almost doubling the rating it got at the original 235° in open air. What did surprise me was that adding a fan seemed to increase strength even more – it’s just a tiny bit, but i’d assume that’s only from the layers lining up better. And really, it should have been obvious, because print quality took a plunge with both the extra temperature and when adding an enclosure. At its worst, even the vertical walls are completely jagged and unusable. Yes, that is very definitely a temperature issue.

Now you could counteract that by increasing minimum layer time, but at the same time, that will reduce layer adhesion, so really, you’re not gaining anything.

So while strength was much better with the higher temperature and the enclosure added, again, it’s a tradeoff between quality and strength, and realistically, if you add all those countermeasures of using a part cooling fan, going slower etc because you’re effectively printing too hot, that’s going to put your prints very close to where you started out. It looks like the filament just has that heat limit of how hot and fast you’re printing, how warm your ambient temperature is and how much heat you’re sucking back out with a fan.

What i also think makes a huge difference in this entire topic is the filament itself, obviously. In this case i used Innofil3D’s material to give it a second chance, but it seems like it’s one of those, i don’t want to say watery, but definitely higher flow and lower melt strength materials. The Esun ABS i have also performs extremely similar there, with you either ending up with weak parts or temperature artifacts. Even rigid.ink’s ASA still profits a lot from the enclosed chamber, but has much less apparent artifacting from it. And particularly ABS blends can perform significantly better or worse than others, as we’ve seen with the REC ABS.

So, should you be using an enclosed chamber for ABS and similar filaments? Yeah, i’d say, it’s a good idea to have one, even and especially for the better filaments, and to be honest, unless you’re living at the equator with no air conditioning, i’d heavily advise against using ABS without an enclosure. It’s not just for how your parts will turn out, but it’s also about health and safety, as ABS is one of the materials with a higher particle count and an enclosure can help keep the fumes constrained. Performance-wise, I’ll just repeat it again, even though i know the comments will disagree, but for normal users that don’t need that last bit of temperature stability and don’t vapor-smooth everything they print, copolyesters aka PET and PETG are just a much better choice. And even for mechanical applications that involve a bit of heat, PETG is a great option. It’s tough, it’s reasonably temperature resistant and so much easier to print well. Point in case – i printed the spindle motor holder for my MendelMax 3 CNC conversion from Ultimaker CPE and DAS FILAMENT PETG and it’s holding up perfectly.

Now, does that mean ABS is universally a bad material and you shouldn’t use it at all? No. It has its uses, but i believe that for many jobs, there are just better and more consistent alternatives out there. Over the years, I’ve not encountered a bad copolyester yet, but I’ve come across many ABS filaments that didn’t perform as expected.

So what do you think? Have you made similar experiences yet? Are you running ABS on a daily basis as your main material?

🛒 Innofil3D ABS [🇩🇪]