ABS vs PLA

When I first started looking into personal 3D printing it seems everyone was using ABS, now PLA seems more prevalent.

3mm filament was the standard and now 1.75mm seems to be the current favourite.

Are there othe materials to concider?

Would someone please give the pros and cons of both plastics and filaments as relates to RepRap machines such as the PRUSA/Mendel.

Thanks,

Bob

Hi Bob, there was a discussion about this just a few days ago. Here's a link to it:

[forums.reprap.org]

Hope it helps

Thanks, that answered a lot of questions. Still outstanding is whether any other plasics are being used...

Seems that PLA is the best to start with while ABS is the one for projects requiring more strength, and filament 1.75 is the "current standard".

Bob

The only thing I'd say is that 1.75mm isn't exactly standard yet. Both are being used by different people. It is true that Makerbot is moving all new machines to 1.75mm, but I think more reprap extruder designs still use 3mm. The only difference between the two is that 1.75mm needs less torque to extrude so it allows simpler non-geared extruders. 3mm was originally dominant because many industrial suppliers already made 3mm filament for non-printer purposes, and a lot of places still sell 3mm cheaper. In the long run it doesn't really matter as long as you build your extruder to fit the filament you intend to buy.

Yeah, I wouldn't say there's a standard filament diameter yet. I'm using 3mm, but only because I have no need to switch.

While PLA prints very nicely for me, I've had some print quality issues occur with it that I haven't seen with ABS. I'm only into this for a few months now, so my experience is limited compared to a lot of folks here, but if I had run PLA at first and had those issues early on, I would have been VERY frustrated and confused.

I started with ABS and once I was printing dimensionally correct parts, my print quality remained very stable. My suggestion would be to start with ABS for that very reason.

I can't help you with other types of filaments, othere than there is some discussion of water-soluable PVA (poly-Vinyl Acetate) support material (for two head machines that can print more complex parts).

The benefit of starting with PLA is that you don't need a heated bed to get it working. And even if you have a heated bed, you don't have to worry about the surface you're printing on because bare glass works great. The debates over what the best surface is for ABS have been going on forever.

On that note, I use PET tape on glass at 110C and I wipe it with acetone after each print and it works fine. I only have to replace the tape if I scratch it with a head crash.

Good point. I had a 110c heated bed from the start and use blue 3" painters tape with great results.

Even so, PLA still stays down a lot better than ABS. One of the things I really like about it. I run the bed at 60c for PLA.