PLA quality differences
I am curious what other people's experience is with the quality of PLA. I use it extensively and am generally quite happy with the results. I use the spools from 123 ink and REAL in the Netherlands. they are about 20Euros. I haven't seen more expensive or much less expensive brands, so I don't know where these brands sit in terms of quality.
Even though PLA performs very nicely in general, I do experience a lot of difference between colours though. While my black and white spools print almost flawlesly and consistently. I have used many spools of this already. When I start a print I am quite confident I can do long running prints with them.
Other colours not so much though. I had a spool of red PLA from CEL on a smart reel that was almost impossible to print with. At the time I thought it was a fluke. A bad (moist?) batch. I haven't had much use for red since, so I dont have any statistical information on it.
But lately I had the same experience with blue PLA. I printed it extensively and noticed over several spools and brands that it had a tendency to clog up. The material did't feel moist (I tested over several meters of filament how brittle it was) It was almost impossible to run a print of 4-5 hours without a clogged nozzle.
And everytime when I gave up for a while, and printed something with my black filament, it ran as smooth as silk again..
The last spool I got was from ColorFabb. I bought this one to try a highly respected brand and see if that makes a difference. But even this one didnt perform better than the others.
So my preliminary conclusion is:
-PLA quality doesnt differ much between brands
- PLA quality differs a lot between colours.
So I would like to know your experence in this area. My main questions are: Do you recognise this experience? And if so, any idea what could cause the difference? Is it the colouring in the filament that makes it more sticky? Any ideas to solve it Would a higher temp help? To be honest, I havent tried that. I still print with the standard profile.
Also I wonder if the simple single material nozzle without needle make a difference. Is it more the needle-valve mechanism more prone to clogging?
@brjhaverkamp PLA quality does differ a lot. CEL PLA is from one of the leading sources and I have seen good quality in the tens of reels I have used, but I have found that the color will cause differences; I suspect in the rate of water absorption.
I suspect that what you are seeing with the "clogged nozzle" is that the filament is swelling the head inlet. A true clogged nozzle requires a manual purge to clear and is usually clogged by external debris. I have only seen three in four years due to the needle valve.
The normal cause I have seen for material issues like you are describing is moisture content. By the time the material is brittle it has a high water content. I would dry the filament and try again.
You should be purging every 10-20 hours with PLA and ABS in the single material print head to clear any degraded material from the print head as these materials degrade over time.
Thanks for your reply. What is your experience with other color PLAs? For me all three of the rols of blue PLA printed cumbersomely. And they were all fresh out of the box/ from the deliveryman.
Indeed I had to manually purge the head quite often. The filament was too stuck to get an eject working or an automatic purge. So I had to unhook the head, eject the filament forward 10cm and cut the wire off. Then I could do a manual purge.
Often I observed that when pulling the filament out, I noticed a long ropy wire at the end. Often a few cms long, It looked like a nylon thread being pulled out. It was not a neat melted stumb as you normally get. As if there was a bit of material in the filament that needed a higher melting point.
Use PETG instead 🙂
Sell all your PLA.
Drying it will be hard as it softens at 50°C and might deform and try to revert to it's natural state, a useless puddle.
If you know how you can heat nozzles and open them to feed the material through, if it is making little popping sounds it is definately wet. The sounds are from moisture boiling away. You might hear this during normal printing/purging.
People have had success drying PLA but personally I would only do it with rice or other non-heating methods. PETG is better than PLA. ABS is my favourite.
For official support please create a support ticket using this link www.cel-robox.com/support/
I haven't tried PETG. Apart from being a bit less expensive, I also appreciate the environmental story of PLA. And so far it suited me well enough. But I will definitely give PETG a try one of these days.
@Ben: I'm still curious what your success stories are in drying PLA. And what the your method is.
@brjhaverkamp PET-G can be a bit stringy, so you need to work on your temperatures by doing test pieces. I've used it a lot, and the G refers to a glycol additive that makes it hydrophobic, so doesn't absorb water like others. This is a 100% recycled product link, and not expensive either.
Personally, I don't use ABS, and use other stuff that is more stable, and prints at a lower temperature. 🙂
@brjhaverkamp I don't dry it. If it gets wet enough that it doesn't work I throw it out. I tried it once and the PLA melted together and made a mess, so I gave up on it and just use PET for the most part now.
Oh, you dont dry. I gathered from your ealier reply that you did. Too bad. I will have to start experimenting.
My main frustration is that this happened with 3 brand new spools. They went straight from the mail-delivery to unboxing to printing and still there was no joy in printing. Since one of them even was from colorfabb, I don't know anymore where to get an even more reliable PLA.
You mentioned earlier you have similar experience with coloured PLA. What is your exact story here?
Although I agree it is a moister issue, since the filament is brittle in some places, I don't recognise the stories about popping sounds while printing. The only noise I recognize is the popping of the extruder skipping.
Would adjusting the temperature upwards make sense? And would the simplified olson ruby nozzle without the valve be more robust against this type of clogging?
The needle valve is unclogging the nozzle every few seconds so the problem is most likely swelling of the PLA in the feed tubes or near the heatbridge. The SingleX head wont change the filament issue.
Try opening the door and cooling the chamber. Reduce the bed temperature and keep the tubes away from the surface. Do you have the metal cable hanger and black plastic cable chain?
We have seen colour effecting temperature requirements in the same material. Mainly in black materials.
For official support please create a support ticket using this link www.cel-robox.com/support/
My Robox was out of service for a while with broken Z-axis and AC cable to the platform, but I am up and running again. Hence the delay in answering.
Thanks for your reply. This was very helpful. I have an upgraded dual material printer, with the metal cable hanger and black plastic cable chain.
Sofar I experimented with the temperature upwards. But your sugestion that this only worsens the situation was unfortunately confirmed Going up to 210'C was indeed not helpful. I am trying now if pushing it down makes a difference. I am trying 190'C now. And it looks like it is slightly better. How far down can PLA go?
I also took out the right side Plexiglass to get the ambient temperature down a bit.
I did try a couple of times ejecting and loading the filament when the print paused because of a filament slip. But that doesn't seem to do much. I did notice that the blue ribbon in Automaker blocks the buttons. One can just reach the upper edge of the button to eject the filament, but I had to look up a screenshot to find it was the second button from the left. Maybe something to improve in the GUIlayout.
I also had the chance to print the exact same roll of filament on a friends Prusa Mk3. It printed without a glitch. So there seems to be something in my Robox.
Any other suggestions on what to experiment with are still welcome.
PLA has serious limitations in durability and thermal stability. PETG or TitanX print really well in the Robox. You should give them a try.
The coloring powders have an impact on the printability of the filament. Usually uncolored (natural), black and white are the colors with the best print results. Black color powder is soot. White color powder is titanium dioxide like in toothpaste or sunscreen. Both color powders give printed parts a certain degree of UV protection in outdoor use cases.
Just to rid myself of some frustration I printed a RFlink gateway box last night (in black), which went right first time. The green turtles I printed for my son previously all ended up in the bin, after clogging the system.
I appreciate the suggestions to move to PETG, I might give it a try in the future. But printing PLA should be a basic capability of any 3D printer. Moreover it is touted everywhere as one of the easiest printable materials. (and cheapest)
There does not seem to be real clogging, I can extract the PLA filament just fine and a manual purge feels very smooth; There is no noticable resistance or blackend chuncks coming out. There just seems slightly too much friction for the extruder to handle. Sometimes when unpausing the printer, it even manages to overcome it and continue printing for a while. I was wondering if there any way to give the extruder a bit more power?