Hey @ThantiK and @Whosa_whatsis , check out my printer. I’m doing everything wrong in your opinions, and yet I get great print quality. Funny.
My year old mendel90 with all printed parts in PLA. PLA bushings on y and z, PLA Greg’s (modded) with the hot end bolted directly into it, and a PLA x carriage. I print everyday, and I’ve had not problems with melting or warping anywhere.
I’m using 9/16 (edit: it’s 5/16) threaded rod on the Z axis and I don’t have z wobble artifacts. At the local reprap meetups, my print quality is right up there with any.
As community leaders, I feel that you guys should be more open to differing ideas. As vocal as you guys are in this community, people might take your opinions on best practices as absolute hard truths, and clearly, some aren’t.
I’m not trying to pick a fight here, just pointing out something that has annoyed me more than once.
Thank you both for everything else you do! I like most of it, except for bad mouthing PLA, and to a lesser extent 9/16 (edit: SAE) threaded rod.
I love the safety sticker. But this does not look like 9/16" threaded rod, it’s too small for that. Probably 3/8-16 (close to 10mm) or 5/16-18 (close to 8mm).
I had a pla x carriage which was just fine until I switched from pla abs. Warps galore with the higher hot end and heated bed temperatures. I take the advice presented on this forum as data derived from experience. Obviously, the tips provided by those with the most experience can yield the most benefit. It is just important to remember that there will be exceptions. I think this is why it is important for all of us to research thoroughly and share our own experiences.
In the case of using pla vs abs for printer parts, the strength and temperature resistance of abs makes it a better candidate for more printer configurations than pla. There have been more then a few examples posted in this community of pla parts failing because of temperature exposure.
Oh, and cool printer. I have always liked the mendel90.
Thanks for the feedback @Brian_Wilson . I think many folks take the advise of this community, so it’s important to get all working ideas out there. And the mendel90 is a great reprap.
Just because you haven’t had problems yet doesn’t mean that you won’t, and it definitely doesn’t mean that others won’t. The active cooling on the thermal barrier makes it safer to use PLA, but I’m guessing you also live somewhere where the weather isn’t particularly hot.
About the rods, have you tried printing sub-.1mm layers? I only see one picture of one of your prints, and it’s not a close-up. I can see so much moire in it that it’s impossible to tell what it a print artifact and what is a camera/scaling artifact.
I’m not saying that you can’t print with those things, but I do have enough experience to know what will have positive and negative effects on the quality, reliability, and longevity of a printer beyond what the average person would consider acceptable, or even “great”. I thought I was getting “great” prints three years ago, but my standards are significantly higher now.
Why pla is a bad idea, not because it is bad in general but in warm climates it warps… I get prints that are okay quality, but I really am not trying for better, because I simply like making things… I don’t need them to be perfect at this, point… but even with the parts you are using you are not getting the best possible prints…
@matthew_bennett You are right, there’s a lot of folk law that’s built up around 3d printing. Take every ‘fact’ with a pinch of salt. PLA is fine for structural stuff, provided it’s kept cool. Isn’t it actually harder and stiffer than ABS (at room temperature)?
@Whosa_whatsis Thanks for the thoughtful response. I should have written in the post that I think almost everything you say is hard earned and quite well informed, based on experience.
You are correct, I live in San Francisco where weather is 50-80F year round. I know you’re in southern, southern California, and @ThantiK is in Florida, and both locations top 100F regularly. And I know you’ve gotta drive there, so I’ll certainly give it to abs for those conditions. But to automatically chime in on any post mentioning PLA printer parts saying it’s wrong (like @ThantiK ) is… not the whole truth for everyone. My experience may be unique, but I think it’s useful to show that PLA can print printers.
On layer height, I mostly print at 0.18- 0.30mm layers, but I have good Slic3r profiles down to 0.05mm. When I say it prints great, it’s because I got compliments on my prints from people who know. Fellow reprappers at the South Bay Reprap meetups, 3D Thursday at @Noisebridge , design night at the Autodesk Gallery, people compliment my print quality and ask me what machine I use. My favorite is “That is as good as the objet at my work. It cost how much?”. So that’s the standards I’m shooting for. It certainly prints reprap parts well enough, which is mostly what I print.
I’d offer to mail you some sample prints, but they’d probably melt in transit. :P.
…and @Whosa_whatsis I read your article about metric rods in Reprap Magazine the day it came out. I totally agree that metric rods will give better prints vs sae rods. I only use these because my local hardware store does not stock 8mm threaded rods. I use metric hardware everywhere else, and find SAE hardware numbers maddening.
@Camerin_hahn , in fact your link prompted this post. And I saw that Gus Simpson in San Jose last night at the reprap meet up. I agree that PLA printers should not be stored or recommended in hot places.
My PLA X carriage warped after one long ABS print, the extruder warped trying to print a new X carriage out of ABS after I metal reinforced a PLA carriage. This is in the cold and rainy UK.
I’m thinking the reason you haven’t warped your X carriage yet is due to the excellent thermal management of the e3d hot end and perhaps because you dont have your bed that hot.
Okay so you can make imperial rods work, but why would you want to? Metric trapezoidal rod has such obvious and visible benefits.
You say you get great quality now, Perhaps if you followed the advice of those who have ‘been there done that’ you’d be getting incredible prints!
It’s not just hot weather that can cause PLA parts to fail (though I’ve seen examples of that that would make anyone who’s ever used a 3d printer cry). I’ve also seen it happen because of the heat generated by an X/Y stepper motor working within its specifications.
Is it possible to thermally manage all of the components of your printer to keep PLA parts from failing? In some climates, yes, but even doing so there, it requires having everything tuned with strong thermal isolation on the hot end (like you have) and the stepper motor current turned down so that they do not deliver their full rated torque. Any beginner is likely to be caught in at least one of these pitfalls over the course of their learning process, which is why I strongly recommend against using PLA parts for printers.
Think of it like recommending that people stop at stop signs. You could never do it and you might never get into an accident or be seen by the police, but would you really recommend that behavior to new drivers?
I’ve managed to partially melt my x-motor-end just with the heat from the stepper - and that was printed with ABS. Just saying.
Sure, there are many ways to do things that work under certain circumstances, but the RepRap project is at a point where people will start suggesting ways to do them properly.
I’ll just chime in here and give my 2 English Pence.
I’ve printed a whole bunch of machines in PLA, including extruders, carriages, motor mounts etc. They work fine, great even, however this is because I’m running the motors cool, and the E3D hotend has pretty excessive heatsinking going on up top, especially the v5. Additionally the E3D hotends have a fan that disturbs hot air convection travelling up and heating the carriage/extruder.
If you’re running a PEEK type hotend, as many do, then it’s not uncommon for the top of the hotend to run up to the TG of PLA, especially seeing as a fan cooling the PEEK is not always used.
Additionally it’s quite within spec to run a stepper motor at 70-80C which will certainly cause PLA to soften. Most of us, me included, run our motors below 50C so this isn’t a problem a lot of the time.
I’ve lost a machine to sun-car-warp, in the English summer. Interestingly the PLA didn’t soften from direct sunlight, but the black stepper motors were exposed to direct sunlight, absorbed a lot of energy, which they promptly transferred to the PLA parts holding them. All the motor mounts failed and drooped under the weight of the motors and the tension of the belts attached to those motors. All other parts were fine.
All my production machines are ABS, some of my experimental/beater machines are PLA because it’s just a bit quicker/easier to crank out a quick part to test an idea.
I have never used any hardware that isn’t metric, so I have zero experience in the banding/rounding error phenomenon.
TL:DR:
You can make a machine just fine out of PLA if you’re careful, but you’re sailing very close to the wind in doing so. IMHO. Also never use imperial units, they’re evil.
My thanks to the veterans for their thoughtful responses. It shows why you guys are deserving of respect in the community. The explanations are most welcome.
See, the thing is with the thought process that @Whosa_whatsis and I have, is that we’re at the level where an “ok” print isn’t good enough. We think a lot deeper into this kind of stuff than others do. Oftentimes getting into the theoretical and past the practical. A lot of it is based on (now years) of experience helping others with their printers. And in this thinking, yes…PLA is always wrong. In practicality, like Sanjay has stated, it’s oftentimes just easier to pump out a part in PLA for quick testing.
I used 5/16" lead screws for a very long time without problem, check my history - you’ll see my i2 running them and me arguing with @Whosa_whatsis over the same damn thing. It wasn’t until I went down to a 0.35mm nozzle, with 0.04mm layer heights that I started noticing the rounding errors that he had told me so much about. At 0.2mm and above, there’s simply not enough definition (generally) to see these errors.
The stance I take, is to correct these mistakes long before it causes someone a headache. Because they are mistakes. You’ll learn that in time.
i guess this is one of those raw parts with garden spares making up a printer that works great. +100. sometimes making up a nice looking printer with loads of technicalities and afterthought prints badly instead, which is sad. i made a XYZ platform using some bits of ikea leftover parts hahahaha, the problem i have is with motor sticking, it gives about 10-20 micron error (measured on a 1 micron scale)
. i hope you could further refine your PLA based printer, good luck
