Why is PLA Ultimaker-Preferred?

[calinb 11]

I also read this statement regarding the Ultimaker: "the company says printing with the plant-based PLA makes for a faster and more stable build." Okay, I understand faster and the lack of a heated factory-supplied bed, but what does "more stable" mean? Is it referring to the warping of ABS without a heated bed?

I'm interested in the Ultimaker for its precision and resolution but I need to print ABS for strength. I have no doubt that I can design, build, and add a heated bed. I've also read that putting a very thin layer of ABS cement on the bed can sometimes keep the ABS stuck down. This requires a glass bed, but might be worth a try. I expect to print very slowly for the best finish possible. Is there any reason I should avoid the Ultimaker?

I will also need to use the full 210mm build dimensions in x and y. Will the Ultimaker actually print to the spec dimensions with ABS? I"m not at all constrained in z in order to produce my intended application (~1" thick, low volume parts for a commercial device) so there'll be no problem in using a small amount of all that Ultimaker z-height for a good heated bed!

Thanks for any answers or responses,

-Cal

[Daid 305]

PLA is no weaker then ABS, the main difference is that ABS is a bit flexible while PLA breaks before it bends.

The main reason why people use ABS instead of PLA is because of the lower melting point of PLA. At 70C PLA starts to get soft.

PLA also achieves a higher precision, it's easier to extrude at thin layers and it shrinks less.

[joergen 2]

As Daid said, PLA is even a bit tougher than ABS in certain configurations.

The main reason is sustainability: I would guess that most things 3D printed are trash (soon), and ABS will not degrade in the landfill, while PLA will eventually disappear.

The Ultimaker is happy to print both (and more) materials, I switched to ABS because I am printing a real product that is heat sensitive, and PLA just gets soft too early, and I can't have customers calling me asking why their expensive product is a puddle with electronics on the passenger seat of their car. but for many other things, PLA is a great material, and you also get more variations with different colors (see diamond age and fabdashery etc), while ABS is somewhat limited in colors, especially when it comes to white.

having printed a small series of my product (360rig.com) by now, you need a heated bed. and you also need to tweak the cooling profile dramatically, because too much/early cooling will still lift the ABS off the glass partially, not enough cooling will cause blobbing from printing on ABS above the glass transition temp. pretty delicate, while PLA is easy: cool as much/hard/fast as you can (more or less).

ABS juice on glass will only sometimes work, probably with items that don't have much surface on the glass. my objects have 70cm^2 direct surface contact, and experiments with ABS juice were horrible: I had a print that wouldn't detach from the glass at all, and actually ripped a huge chunk of glass out of the surface: See http://forums.reprap.org/read.php?4,121996,132804,quote=1 for more discussion about it

[joergen 2]

As Daid said, PLA is even a bit tougher than ABS in certain configurations.

The main reason is sustainability: I would guess that most things 3D printed are trash (soon), and ABS will not degrade in the landfill, while PLA will eventually disappear.

The Ultimaker is happy to print both (and more) materials, I switched to ABS because I am printing a real product that is heat sensitive, and PLA just gets soft too early, and I can't have customers calling me asking why their expensive product is a puddle with electronics on the passenger seat of their car. but for many other things, PLA is a great material, and you also get more variations with different colors (see diamond age and fabdashery etc), while ABS is somewhat limited in colors, especially when it comes to white.

having printed a small series of my product (360rig.com) by now, you need a heated bed. and you also need to tweak the cooling profile dramatically, because too much/early cooling will still lift the ABS off the glass partially, not enough cooling will cause blobbing from printing on ABS above the glass transition temp. pretty delicate, while PLA is easy: cool as much/hard/fast as you can (more or less).

ABS juice on glass will only sometimes work, probably with items that don't have much surface on the glass. my objects have 70cm^2 direct surface contact, and experiments with ABS juice were horrible: I had a print that wouldn't detach from the glass at all, and actually ripped a huge chunk of glass out of the surface: See http://forums.reprap.org/read.php?4,121996,132804,quote=1 for more discussion about it

[joergen 2]

As Daid said, PLA is even a bit tougher than ABS in certain configurations.

The main reason is sustainability: I would guess that most things 3D printed are trash (soon), and ABS will not degrade in the landfill, while PLA will eventually disappear.

The Ultimaker is happy to print both (and more) materials, I switched to ABS because I am printing a real product that is heat sensitive, and PLA just gets soft too early, and I can't have customers calling me asking why their expensive product is a puddle with electronics on the passenger seat of their car. but for many other things, PLA is a great material, and you also get more variations with different colors (see diamond age and fabdashery etc), while ABS is somewhat limited in colors, especially when it comes to white.

having printed a small series of my product (360rig.com) by now, you need a heated bed. and you also need to tweak the cooling profile dramatically, because too much/early cooling will still lift the ABS off the glass partially, not enough cooling will cause blobbing from printing on ABS above the glass transition temp. pretty delicate, while PLA is easy: cool as much/hard/fast as you can (more or less).

ABS juice on glass will only sometimes work, probably with items that don't have much surface on the glass. my objects have 70cm^2 direct surface contact, and experiments with ABS juice were horrible: I had a print that wouldn't detach from the glass at all, and actually ripped a huge chunk of glass out of the surface: See http://forums.reprap.org/read.php?4,121996,132804,quote=1 for more discussion about it

[joergen 2]

As Daid said, PLA is even a bit tougher than ABS in certain configurations.

The main reason is sustainability: I would guess that most things 3D printed are trash (soon), and ABS will not degrade in the landfill, while PLA will eventually disappear.

The Ultimaker is happy to print both (and more) materials, I switched to ABS because I am printing a real product that is heat sensitive, and PLA just gets soft too early, and I can't have customers calling me asking why their expensive product is a puddle with electronics on the passenger seat of their car. but for many other things, PLA is a great material, and you also get more variations with different colors (see diamond age and fabdashery etc), while ABS is somewhat limited in colors, especially when it comes to white.

having printed a small series of my product (360rig.com) by now, you need a heated bed. and you also need to tweak the cooling profile dramatically, because too much/early cooling will still lift the ABS off the glass partially, not enough cooling will cause blobbing from printing on ABS above the glass transition temp. pretty delicate, while PLA is easy: cool as much/hard/fast as you can (more or less).

ABS juice on glass will only sometimes work, probably with items that don't have much surface on the glass. my objects have 70cm^2 direct surface contact, and experiments with ABS juice were horrible: I had a print that wouldn't detach from the glass at all, and actually ripped a huge chunk of glass out of the surface: See http://forums.reprap.org/read.php?4,121996,132804,quote=1 for more discussion about it

[joergen 2]

sorry for the double posts, the forum software went gaboogle, please delete the duplicates

[calinb 11]

Daid, Joergen, Thanks for your replies. Your assistance is immensely helpful!

Has anyone confirmed that the head can deposit ABS across the full 210mm x and y dimensions? I expect that ABS build volume would not be significantly different than PLA volume, but I always distrust specs, in any case. I might even find better plastics for this application but I also require colored plastic or at least orange and yellow--perhaps even the fluorescent plastic, which might be really cool!

>why their expensive product is a puddle with electronics on the passenger seat of their car.

This would be a problem for me too. I need to house electronics in an impact and heat resistant container. The passenger seat of some very hot US climates would be a problem but I'm an electrical engineer, rather than a materials or mechanical engineer, and I assumed ABS would not shatter as easily as PLA under impact. Maybe PLA would be sufficiently impact-resistant too, but you have alerted me to a very relevant limitation of PLA, Joergen.

[joergen 2]

One problem you will encounter is ABS shrinkage, which has nothing to do with the UM, but ABS in general. The next thing that will be a monkey wrench is the cooling gradient along the edges, if you are using a heated bed platform (can be aliviated by closing off the sides with cardboard.

I have also not tried to really push it to the far corners, I think 195mm was the largest object I've printed.

In terms of stability, the same design rules apply for everybody: if you want to be more structurally sound, bulk it up in strategic places. Both plastics can be ridiculous structurally sound. Look a the "go wide or go home" project on xperiastudio.com - this thing is so solid, I can easily stand on it.

Overall, I would say that if you adjust your model to the reality of the plastic extrusion on the UM (or any other 3d printer), you can be successful with the UM. Mine is working fine so far.

[calinb 11]

Wow! Thanks for sharing your work, Joergen. That wide camera is super cool! When I was younger and fitter, I rode mountain bikes. Your invention is certainly exposed to significant shock and vibe!

I need to produce prints with the best possible finish, which might require post-processing in a solvent tank dip and following-up with a light bead blasting to restore the matte finish. The UM has very fine movement capability and I've read about 40 micron slices being quickly generated with netfabb. Do you feel that the atypically fine movement capability of the UM is an advantage, compared to an average 3D printer in this price range, when striving to optimize finish quality? From what I've read, calibration is probably the most important factor that affects finish quality. I've calculated that my part would now consume somewhat less than 1/2 lbs. of ABS maximum, but I plan to reduce that number by adding cavity "wells" in the part. I don't care if they take a day or two to print.

Again, I appreciate the time you've taken to help me.

-Cal