Differences between ABS and PLA? Which is best?

[Sebastian Finke]

I would add a few things to this list:

The main differences are fairly simple.
pros:
1) abs is cheap and has good mechanical properties.
2) you can use acetone to make it smooth and pretty.
3) it can be cold-welded

cons:
1) unless printed in a fully heated enclosure - warps like a bastard.
2) you pretty much end up breathing in a lot of acetone fumes. Only at temperatures exceeding 400C!
3) makes your workshop smell like burning plastic It doesn't smell as pleasant as PLA, granted, but certainly not like burning plastic.
4) can be tricky to make stick to print surfaces. Absolutely not true

pla.
Pros:
1) very easy to print with, warping varies from none to a tiny amount.
2) will stick to just about any print surface
3) so many types around that there will be one that does what you want it to
4) good general prupose pla is cheap.
50 no real smell when printing. Actually I think it smells great.

cons:
1) specialist pla filaments can be pricey, although flexible pla is cheaper than tpu (polyurethane based) flexible filaments and much much easier to use
2) cannot be cold-welded.

The point is that abs is a long standing plastic that was developed for injection moulding. Whereas todays pla filaments have been specifically developed just for 3d printing.

This is absolutely untrue. PLA has been around since the 1930's (if I recall correctly it was developed by DuPont in 1932) and is used extensively in injection moulding particularly in the food packaging industry (yoghurt tubs, etc) and also disposable cutlery and plates (like camping gear).

[ServiceXp]

The main problem is that there is no such thing as 'pla'. There are several hundred hundred different materials - all with different specifications and properties that are called 'pla'.

So while abs - is pretty much just abs - there are variations that warp less, have higher temperature usages etc - but compared to pla - damn few of them.

So while the pla you got 5-10 years ago was fairly limited - today you can get a pla based filament with just about any properties you like.
There are pla filaments that outperform abs in all properties. there are bendy pla's. hi-temp plas, conductive, carbon fibre reinforced.

So one thing to instantly dismiss when comparing abs and pla is the myth that pla is brittle, shatters or in any way weaker than abs. It's not, if you buy the right pla :-)

The main differences are fairly simple.
pros:
1) abs is cheap and has good mechanical properties.
2) you can use acetone to make it smooth and pretty.

cons:
1) unless printed in a fully heated enclosure - warps like a bastard.
2) you pretty much end up breathing in a lot of acetone fumes.
3) makes your workshop smell like burning plastic
4) can be tricky to make stick to print surfaces.

pla.
Pros:
1) very easy to print with, warping varies from none to a tiny amount.
2) will stick to just about any print surface
3) so many types around that there will be one that does what you want it to
4) good general prupose pla is cheap.
50 no real smell when printing.

cons:
1) specialist pla filaments can be pricey, although flexible pla is cheaper than tpu (polyurethane based) flexible filaments and much much easier to use

The point is that abs is a long standing plastic that was developed for injection moulding. Whereas todays pla filaments have been specifically developed just for 3d printing.

I Print almost exclusively with ABS, and while it's slightly more tricky to work with than simple plain Jane PLA, it's not nearly as difficult as some of the specialty PLA's (from what I've been reading). From my experience with ABS, I would almost go as far as saying all your ABS cons are grasping at straws, with maybe #1 being the exception. While it's not impossible to keep small ABS objects from warping without an enclosure, it does make it easier.

All that said, I do suspect there are many PLA filaments out now with much better characteristics than ABS, but man some of those filaments are crazy expensive, and ABS is cheap for strength.

[Nargg]

4) can be tricky to make stick to print surfaces. Absolutely not true

Not sure what fairy dust you use to make this not true. It's unfortunately very true for most folks that try ABS 3D printing.

[ServiceXp]

Must be the same 'fairy dust' I'm using, because it's a non-issue for me as well. No problems with ABS here..

[EagleSeven]

!!! Wow, where can I get some Aqua-net Spray with 'fairy dust' in it ???

My large ABS prints all look like rockers for rocking-chairs !

[Sebastian Finke]

!!! Wow, where can I get some Aqua-net Spray with 'fairy dust' in it ???

My large ABS prints all look like rockers for rocking-chairs !

That's 'cos you're doing it wrong

[EagleSeven]

That's 'cos you're doing it wrong

That's what you guys keep saying but I've not heard any Good suggestions about how to fix the 'Extreme Warping',
except for 'Fairy Dust' !
I've tried All the suggested nozzle and bed temps and speed changes, and it does Not help !
I'm certainly not going to use some radical Glue to hold it down !

If Aqua-net can not hold it down, then it will not be used in our printer !

[Sebastian Finke]

You haven't heard any good suggestions? I have been repeating this since I joined: enclose your print chamber and preheat it before printing.

[curious aardvark]

it's not nearly as difficult as some of the specialty PLA's (from what I've been reading).

don't know where you're doing your reading - but I've tried most of the weird and wonderful filaments out there and they ALL stick to gluestick, none of them warp and they all print just as easily as decent pla.

Most of them don't need heated buildplate - none of them need a heated enclosure. And because you don't need rafts and prints rarely fail - even the expensive ones are actually pretty cost effective. As long as you design and print properly :-)

I did do a fair bit of printing with abs, before, I finally tried pla and realised everything I'd heard, was just so much nonsense.

Don't have heated enclosure, always used a raft. Apart from the odd crack and ocasional issues getting the raft off after a long print - it printed okay.
But just okay - you needed to adjust for shrinkage, and that was annoying - don't need to do that with pla.
Hell I even printed a secret heart box with abs.

But the smell when it's printing is unpleasant, acetone is not good for you and my pla prints - so far - have been stronger, less brittle, stiffer and just all round better parts.

I don't print figurines or pretty models. Most of my prints are original designs, either relacing a broken widget or making something original for a specific purpose. So having something look shiny and smooth - is not any part of my desing brief :-)

That said - un processed pla prints look much better than un processed abs prints. Abs looks kinda dull and rough. pla tends to be a bit shinier and smoother looking.

[EagleSeven]

You haven't heard any good suggestions? I have been repeating this since I joined: enclose your print chamber and preheat it before printing.

Oh, okay, if Enclosure is really needed to use ABS ,
I certainly will Not be trying ABS again, since we like an Open style printer
and enclosure is not needed for other filament types that we use.

Thanks for Info !

Note: I was Hoping for *GOOD* suggestion !