Differences between ABS and PLA? Which is best?

[jeffmorris]

Differences between ABS and PLA? Which is best? I have PowerSpec Ultra 3D printer. I would like to make robot parts and model cars.

[Sebastian Finke]

ABS is a polymer whereas PLA is a polyester. Which is better? Depends on the application. Either will do for your needs although ABS will be more shock resistant.

[EagleSeven]

PLA has less warping than ABS

[jeffmorris]

What about PETG? I'm not sure if it will work on my printer.

[Sebastian Finke]

The old warping argument... ABS will warp if you don't treat it right. Just printed a diameter 138mm x 2mm disc with 19mm high wall along the outer perimeter... not a shred of warping or cracking.

[jeffmorris]

There is a label on the spool for ABS filament that says: Print Temp: 220-260C. That is for the extruders. It doesn't say anything about temperature of build platforms. I think that the default temps for ABS in PowerPrint are 220C and 105C. Are they OK or do I have to change them?

[Sebastian Finke]

Lower the bed temp to 100. 95 or even 90 work too. Takes a bit of experimentation to nail it. Mine is at 100.

105 is the glass point of ABS so you really want to stay under that.

[EagleSeven]

What about PETG? I'm not sure if it will work on my printer.

Both PETG and HIPS will work and both warp less than ABS .

[Bobby Lin]

I agree with everything stated above. If you want more details about the difference between the two, you can read this one.

[curious aardvark]

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.