Why all the rage for PLA?

[jwalrath]

Guys,

First off let me say thanks to everyone in the forum for all the useful info. Over christmas break I built a V2 with my kids and have been having a blast with it - until yesterday. I started with ABS and got everything calibrated (again the forums really helped here) and setup. Printed out over 300 meters worth of doodads. No problems at all once all was dialed in. Actually did a 20 hour print with no problems.

So yesterday decided to try the PLA. Man what a pain-in-the-rump!!!! Finally got a few parts out of it but man that stuff is finicky with respect to temps, jamming, and temps!!! The parts that came out looked great by the way. Just so many problems. I would print a part and then on the start of the next print - jam. Most jams where in the EZstruder (I already posted a note already in another section about that one - temps with stepper motor I think).

So my question is why all the buzz and general recommendation to go with PLA? I do not understand it. In several forums, including this one, I always see people recommend using PLA over ABS or switch to PLA when there is a problem with a specific print. Obviously I am missing something here but I do not see the attraction of PLA? So far I am not impressed.

Just wondered what other's thoughts were.

Note that once I got things dialed in and could get the jams all straightened out I got a couple of good parts but still what a pain.

-jeff

[Captain Starfish]

I think you asked the better question in the thread subject line.

I too, have nothing but rage for PLA.

ABS leaves it for dead. And then Nylon leaves ABS for dead in many applications.

[jwalrath]

Thanks - glad I am not alone here.

Is taulman the only nylon out there? I take it that it is worth the extra money then? Which is better: taulman 618 or taulman 645? Does it have the shrinkage/warping issues of ABS?

-jeff

[Jimustanguitar]

Cap'n is right. If you try ABS first, you'll be very impressed with PLA. It bridges better, it doesn't warp and unstick as much, no cracking or delamination, etc. It's not always the ideal material to make things with (too brittle sometimes) but it's definitely the most printer friendly material that I've used so far.

[Captain Starfish]

wait, what.

PLA is rubbish. The only thing it's got going for it is easier bed adhesion so far as I can see. That's important for someone starting out - the less headaches the better when you're trying to dial everything in and get your head around it all. Cheaper printers without heated beds? When PLA is pretty much the only choice, it's a good choice. And the fact that you can burn it out of an investment casting - one day I'll get a round tuit then I can make a foundry and start playing with metal, and this is the only reason I haven't chucked my PLA in the bin.

But it looks like crap for cosmetic prints and it's useless for structural parts because of how crackingly brittle it is. Plus I want my man cave smelling of burning plastic and other industrial stuff, not the rainbow flavoured unicorn farts that PLA gives off. No idea what it's like exposed to the elements either, heard mixed reports but the whole biodegradable thing leaves me unwilling to print anything long lasting with it.

ABS takes more work to get it to stop pulling off the bed, granted. But it's strong, it can take a beating, it looks good and the whole acetone thing means you can get amazing finish off it.

Nylon - I'm using the blue weed whacker line from Amazon and some purple glass filled stuff from a local hardware supplier. I have the Taulman as well, it's nice but eleventybillion more expensive. You need an all metal hotend to print it, because the 260º or so it takes for the weed line will slag your PEEK heatbreak and your liner in the stock one.

Nylon is nice to print, although it lacks stiffness (quite advantageous a lot of the time, useless at other times) and it turns to rubber if soaked in water. Somewhat problematic when a lot of what I'm printing at the moment is dive gear When the Amazon stuff costs half normal filament, though, it makes a pretty nice material for belting out test prints and suchlike.

[dunginhawk]

Im glad someone finally brought this up... Ive been printing a lot with PLA lately, just to try some things out.
I made my kids a train set (tracks, cars and all) and the PLA is SOOOO brittle, a drop on the wood floor and shatter time.

With the exception of maybe lego type blocks, and a few other things I am heavily leaning in favor of ABS.

QUite honestly i bought and have PLA (and some on the way yet) because literally everyone is a PLA fanboi so I figured I must be missing something.

Perhaps im not, perhaps my love for ABS over PLA is being reciprocated

[nitewatchman]

Commercial Legos are ABS for just the reasons you mention below.

[jesse]

PLA smells better melted and is biodegradable. I'm using the original side mounted geared extruder which provides more force than the EZ struder.

[geneb]

I print with PLA pretty much exclusively and I never have any problems with it. That big green part I posted a photo of in another thread is PLA.

g.

[jwalrath]

Geneb,

Which brand of PLA are you using? I am using the SeeMeCNC brand. This thread shows what one of the jams looked like (and I am using the slow speed settings to get really clean prints - i don't need the speed).

http://forum.seemecnc.com/viewtopic.php ... 496#p56496 (look at fourth post from the start). For me the desk fan did stop these types of jams for the most part. I was able to get more consistent prints in a row.

-jeff

[geneb]

The part I referenced was printed using a roll of green PLA I got from Inventables about 18 months ago. I run it at 210C and it prints wonderfully. There's two things to be aware of with PLA.
1. the PEEK fan must be running and not be blocked. If you get heat creep in the cold section of the hot end, it's all over but the crying.
2. A layer fan is *required*. It prevents heat build up in the prior layers that would make a mushed mess of the print.

g.

[heathenx]

I'm with geneb. I prefer PLA. It prints so much easier than ABS or Nylon. Contrary to what people believe, you dont need a PLA fan if you print slowly.

[Jimustanguitar]

wait, what.
PLA is rubbish.

I completely read your first post the opposite of how you intended it...

I like PLA a lot better than ABS, but they're definitely ideal for different applications.

[Earthbound]

I make things from ABS when I need one or more of the properties of ABS. I use PLA the rest of the time. I use 25x more PLA than ABS.

In 2500m of PLA used, I have had only a single jam. I attribute it to contamination (a visible inclusion) in the cheap PLA I use.


I am always puzzled when I read of people having numerous/frequent jams when using PLA. I don't think I'm doing anything magical. I buy really cheap PLA. I use what I think are fairly large, fast, frequent retract settings. I've printed both fast (>100mm/sec) and slow (5mm/sec). What is the recipe for trouble? I have taken no steps to cool the extruder (bone stock EZ-struder). The only thing that is not "stock" on my stock hot end is the PEEK fan. The one supplied with the kit was junk and broke apart while I was installing it in the fan shroud, so I ordered a different 25mm from a different vendor. So why don't I have these PLA jamming issues? Could the spring tension in my EZ-struder be different? Maybe the "teeth" of my hobbed gear are different? Maybe the path of my bowden tube is less restrictive? It has to be something. I don't seem be be able to make mine jam up.

[Captain Starfish]

wait, what.
PLA is rubbish.

I completely read your first post the opposite of how you intended it...

I like PLA a lot better than ABS, but they're definitely ideal for different applications.

Haha I was scratching my head - you agreed but then say the complete opposite

It could be a case of horses for courses, granted. I don't make a lot of decorative stuff. It's pretty much all parts for use which need to be structurally reasonable, something I've never achieved with PLA. And once you're set up with a filament that does everything, it's effort the lazy - oops - efficient printer person doesn't want to waste in switching settings etc for something else.

[Polygonhell]

I'm not sure PLA is "easier" to print with, but the issues most people have with ABS, i.e. delamination and large parts warping are pretty much none issues in PLA. Instead you get a different set of issues.
PLA is rarely my choice for structural parts, but even there it has it's place. I had all sorts of issues printing a dimensionally accurate vertex for a mini Kossel in ABS, it would print fine look fine until you removed it from the bed and could see the distortion, caused by the warping forces.
I had no failures printing the same parts from PLA.
I like many of the properties of Nylon, hate the warping.
I'll use whatever I think will work best for a given part.

[dunginhawk]

Im not even talking about the ease of printing with one or another.. i could care less about that...

What i dont understand is what people are printing with PLA? Anything that I want to use, i mean really use has to be ABS IMO... pla is just too brittle..
Now for vases, or some decorative stuff etc I totally get it, but i just find PLA is finicky and brittle. abs is flexible and strong. again, thats just me

[bot]

PLA is stronger than ABS, in most respects.

ABS is more flexible. This allows it to bend without breaking, and to be much more impact resistant.

They are two totally different materials, and just because they both are popular for printing, shouldn't be compared. One is stiff, and strong, one is flexible and not as strong. There are many other differences as highlighted, choose your poison.

[McSlappy]

PLA is my choice. It's way easier to get to stick to the bed, it smells nice, doesn't shrink (much) and requires lower temps. However, it is a little more finicky in the hot-end and sometimes jams (basically it's toffee). If you can sort out any hot-end issues you might have (I just do the old drop of cooking oil when starting a print) then it's awesome stuff!

For me ABS is fine but it requires such a solid bond on the first layer and really needs some breeze control to work well.

As far as hassle factor goes, PLA is much less work for me and that's why I use it.

If you have jams, use oil and life will be rosy!

[BONE]

I'm with geneb. I prefer PLA. It prints so much easier than ABS or Nylon. Contrary to what people believe, you dont need a PLA fan if you print slowly.

Except on small parts and features. Depends on the cycle time of each layer.

[lightninjay]

Just wanted to put in my two cents as to why I love PLA so much.

I managed to print a cello with it...

It plays acoustically quite well, and I'm also currently designing an electric version.

[jwalrath]

Guys,

So I have a status update since my original post. I took earthbounds comments about having no issues and spent several hours trying to track down the issue. It was definitely an EZstruder problem but not the heat as I originally thought. I think that was a symptom of what was really going on. What I found was the the PTFE tube running from the EZstruder to the hotend had some sort of hole size anomaly or something. Right after a jam, I tried pushing the material by hand and it wouldnt budge. When I went to put the filament back out, the tube came out with it. There was no big bulge at the end of the filament that would have made the tube come out of the hotend but it was still grabbing the tube. It took the tube off, cut the end of the filament and tried running filament through it by hand. Sure enough once it got close to the end of the tube, it was a lot harder to push the filament. I replaced the PTFE tube and so far the last 3 prints have gone smoothly and jam free. I am still not sold on PLA but at least I can get some parts out and not have to spend so much time fixing jams.

I was going to try the canola oil trick but since the jams have stopped I will wait and see.

Thanks for all the feedback.

-jeff

[teri1337]

Lightninjay - you printed that cello in PLA? That's amazing! I assume you printed in pieces then glued them together somehow? How did you handle supporting the string tension? The instrument is beautiful! Well done!

(Oh, and for the record, I prefer printing in PLA as well. I only print in ABS when the part requires it.)

[Eaglezsoar]

The Cello is one of the best prints I have seen from a 3D printer. An excellent job!
A wave file uploaded here that allows us to hear the tonal quality would be great! (hint)

[lightninjay]

Teri, I modeled the whole cello in autocad and then broke it into four sections that could fit within the build height of the printer. Then I designed threads directly into the parts so I could bolt hardware through the sections to hold them together. Lastly, I took a note out of the "F-F-Fiddle"s handbook and threw in a threaded support rod that runs the general length of the cello in order to take most of the tension of the strings.

The seam is one of the printing breaks, and the little slot on bottom holds a 1/4in. nut to help prevent thread-stripping as the pieces are tightened together.

Carl, thank you so much for your praise! Saying something of that magnitude means a LOT coming from you, having seen so many prints in your time here. Here's the tonal quality you requested!

[youtube]http://www.youtube.com/watch?v=m4EP1y5HThM[/youtube]

One note I would like to make, the video was taken using a cell phone camera and microphone in a closed bedroom space that tends to echo a bit, so I personally don't think the video demonstrates with true justice, the actual sound of the instrument.

That being said, I'm currently doing work on an electric pickup for my cello design which will allow amplifying and modification of direct sound waves generated by the strings' physical vibrations in space.