Monday, September 2, 2013

PLA vs. ABS printing

There are pros and cons for either PLA or ABS material printing. Here are my experiences so far.
(Please feel free to provide feedback so I can include other's experiences and knowledge).

Side note:   Since I have still have had some cartridge filament binding issues, I currently run all my filament spools outside the cartridge on an external holder to avoid a ruined print, and can keep an eye on the spool and filament. (see other post for more info).
That's how the other 3D printers have it anyway.

In general, printing flaws shows up most with black filament, just like you can see dirt more on a black car.


PLA Pros:
Prints in general come out cleaner and smoother. (except some 0.10 resolution come out worse than 0.25 resolution because printjet gets pulled away in between layers leaving a lot of "fuss" on the part.)
The material is overall harder, but therefore can crack or break easier if flexed too much.
Printed part dimensional tolerances are more accurate.
Can be drilled and tapped.

PLA Cons:
More difficult to "clean up" after print.
Can be sanded or filed, but looses surface color finish and gets whitish were cut or sanded. (sanding or cutting marks are least visible on white PLA).
Parts get soft and can warp if exposed to hot temperatures.

ABS Pros:
Easy to clean up and rework after printing.
Can be easily sanded, filed.
Can be drilled or tapped.
Dull or shiny surface finishes can be achieved with acetone and a rag.
Higher temperature resistance.
Support features are easier to remove.

ABS Cons:
Print limitations because of higher material shrinkage and warping if you don't have a heated print bed.
Some part tolerances or features might not come out as accurate or sharp as with PLA.


These are the tools I use for part clean up after printing:

Tools for PLA parts:
  • Exactor knife
  • Flush cutters
  • Sand paper (seldom used on PLA)
Tools for ABS parts:
  • Exactor knife
  • Flush cutters
  • Sand paper
  • Acetone with rag (read safety labels for acetone)



Here are some print examples:  (click on the pictures to enlarge).

This Garmin Bike mount was printed in PLA and ABS, both seem functional print quality equivalent.
I tried printing the part in 0.10 PLA, but came out crappy and was aborted early.
In general, 0.25 resolution works best for PLA.
 
 

Here is a PLA print resolution comparison where the 0.25 produces a better print quality than 0.10.
This model is only 2" tall.




The same model was printed with ABS in 0.10 resolution.
The print quality of the 0.10 ABS model coming right of the printer, looked somewhere between the 0.10 and 0.25 PLA print.
The difference is that with PLA print, there is not much improving you can do to the printed part besides cutting off the fuss and strays. the print lines will still show. That is no problem in functional parts, but might not look as good on "visual" models.
As you can see on the Batman head below.


Here is another model printed with PLA and ABS both in 0.25 resolution.
The 0.25 PLA print came out nice without much cleanup needed.
The 0.25 ABS print came out equally nice, but could be even more improved with an acetone wipe.






 
 
 
For the next example, PLA was a better material choice. The part being fairly long (7") and less than 2mm thick, did not work so well for ABS. I am not sure if a "thick" fill would have made a difference, since the software does not handle thin walls so well and leaves them hollow.




And another print comparison.
This Tarbosaurus skull came off the printer cleaner in PLA, but the end result after clean up can be quite more realistic looking with the ABS part since it can be easily sanded and an acetone rub to blend (melt) in the print lines so they are not visible,






 
 
0.10 Resolution seems to work better with ABS than PLA. (stick with 0.25 for PLA).
Here are some nice prints with ABS 0.10 resolution. These came off the printer very clean.
 
 
ABS White  0.10 resolution



 
 
 
 



 
 
 
 


Sometimes no matter what you do, the print won't come out as expected, which can be just the limit of the CubeX software created build file or model geometry.
Always try to position the model to minimize overhangs.

All my print comparisons were printed with heated print bed.
Some parts with a very small foot print might come out ok with ABS on standard print bed.

I am planning to do the next post on support structures and print orientations.



5 comments:

  1. You can use a jet type lighter to get rid of the scaring made when cleaning PLA, just don't keep the the heat in 1 spot for too long.

    Karl

    ReplyDelete
  2. Could you please share the file for the Eiffel Tower? It has ridiculously nice detail. How did you print that without any supports or rafts?

    Thanks!

    ReplyDelete
  3. Here is the link for the Eiffel tower file:
    https://sites.google.com/site/cubex3dprinting/files/EiffelTower_fixed.stl?attredirects=0&d=1
    I got it from "Thingiverse".
    I printed it at 190 percent scale, otherwise the features are too small. (that's about as big as it could be printed with the CubeX). I printed it with PLA, 0.25 resolution, hollow (you could use any infill), no support, no raft.

    There is also a model on Thingiverse where the tower is split into two pieces, so you could print a bigger tower.

    ReplyDelete
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