Large multi-day print warping (Printing with Polycarbonate)
Hello, I have a few questions about printing things with Polycarbonate.
I recently started printing a large mount for a speaker, and I decided to print it out of Polycarbonate. I don't have that much experience printing with Polycarbonate, I just picked up a spool, did a few test prints, and started the mount and put the PC in a drybox while printing. It is a 3-and-a-half-day print, and about 1 day and 18 hours in, I checked the print, and it was warping a lot (see pictures). This was weird, as I checked the print the same morning, and it looked fine. 7 hours later however, the whole front of the print started to warp 2-4mm off the print bed. It's not the end of the world, as the print could probably still be used, but I need to print more mounts so I kind of want to figure this out.
I know that PC has a tendency to warp, which is why I used the enclosure, but it still warped. Could it be that the front door is not sealed enough, and drafts are getting through? Or that the chamber cooled down too fast? (The chamber was at 38°C when I started the print, and when I checked it, it was at 35°C) I would love some help, as I love PC and I want to print a lot more parts with it in the future.
-JCL
RE:
Just out of curiosity, what was the reason for Poly?
I am having smaller issues with PLA where the corners are starting to warp but not this bad. I often wonder if the temps in the bed change somehow especially out near the perimeter of the bed. I have seen some posts on Poly and drafts are very effective with this material and your 3°C change in temp doesn't seem too drastic but what was the cause of this? Is the temp controlled in the enclosure? I don't see any kind of glue on your plate?
RE: Large multi-day print warping (Printing with Polycarbonate)
Hi,
Why dont you use brim or skirt?
Adding some 3DLac Spray on the bed may Help
RE: Large multi-day print warping (Printing with Polycarbonate)
Printing huge squarish parts on polycarbonate you’ll need all the possible help to keep warping under control.
I’d print on the smooth sheet. It has better adhesion than the satin or textured. Add a large brim and/or Mickey mouse ears.
Use some kind of adhesive. Hairspray based products like Laverneer or 3Dlac are fine. Dimafix is still better with a bed temperature of 90C or above. Besides, if you use the smooth sheet, you need a separating layer between bed and print. Otherwise you might damage the plate when removing the part.
Try to keep the temp. inside the enclosure high and constant. Place the model as far as possible from the front, where the bed is likely to be a bit colder.
Unless it’s strictly necessary for strength reasons, keep the infill percentage under 30-35%.
RE: Large multi-day print warping (Printing with Polycarbonate)
Warping is the nature of the beast with fdm in general, and the higher the required printing temperature, the larger the parts, the worse it'll be.
The warping is caused by the unequal cooling of the plastic. As plastic cools it shrinks. So the further you get from the heat bed the faster it cools. Corners cool faster than the rest of the part, which is why corners typically curl up. Rounded corners because they have more mass cool slower than square corners so a radius is better if possible.
Other factors are infill, which will cool faster than solid sections, and basic changes in part geometry cool differently.
The reason an enclosure helps is because the higher you can get the chamber temperature the slower the plastic cools, thus helping with warping.
In order to get minimal to no warping you would need an industrial printer that can have chamber temperatures from 60 to 90°C, which your never going to get with our hobby printers.
That being said things you can do to help include rounded corners, brims, maintaining constant part thickness where possible, avoid big thick sections of possible, and higher chamber temps (there's a limit to what we can do here with our printers. I wouldn't go much more than 40° - 45°C or you'll start having other issues).
I'd also consider making your part from PLA if it's going to be inside your house. PLA will warp much less than PC and will be plenty strong. Plus PLA prints really nicely. If you use PLA be sure to use the PEI print sheet as PLA sticks much better to that.
Good luck.
RE: Large multi-day print warping (Printing with Polycarbonate)
Just out of curiosity, what was the reason for Poly?
I am having smaller issues with PLA where the corners are starting to warp but not this bad. I often wonder if the temps in the bed change somehow especially out near the perimeter of the bed. I have seen some posts on Poly and drafts are very effective with this material and your 3°C change in temp doesn't seem too drastic but what was the cause of this? Is the temp controlled in the enclosure? I don't see any kind of glue on your plate?
So, the item I am trying to print here is a speaker mount, a speaker that weighs about 25 pounds. So we want to use PC filament for strength.
The enclosure isn't temperature-controlled, and we were not yet using glue for this print (we are now, see following replies).
I have run into very few problems with PLA or PETG, in fact we did a test print that came out perfectly before trying it with PC.
-JCL
RE: Large multi-day print warping (Printing with Polycarbonate)
Hi,
Why dont you use brim or skirt?
Adding some 3DLac Spray on the bed may Help
We are now trying some tests with a brim, then a "super" brim, and finally with a skirt or draft shield.
The "super" brim made the most difference, basically 3-layers (0.6mm) thick and I think 1omm or more wide, and with some additional small triangular supports.
The glue we are now experimenting with is called Magigoo MPC2018 (made for polycarbonate). It definitely has an effect, just not enough yet.
-JCL
RE: Large multi-day print warping (Printing with Polycarbonate)
Printing huge squarish parts on polycarbonate you’ll need all the possible help to keep warping under control.
Yeah, the definitely appears to be the case for us.
I’d print on the smooth sheet. It has better adhesion than the satin or textured. Add a large brim and/or Mickey mouse ears.
When you say smooth sheet, are you talking about the regular one that came with the printer or a specific one?
What are Mickey mouse ears?
Use some kind of adhesive. Hairspray based products like Laverneer or 3Dlac are fine. Dimafix is still better with a bed temperature of 90C or above. Besides, if you use the smooth sheet, you need a separating layer between bed and print. Otherwise you might damage the plate when removing the part.
We are playing with Magigoo for PC as I mention above, it's an improvement but not much.
I will look into the Dimafix product, as we are already into those kind of bed temperatures.
Try to keep the temp. inside the enclosure high and constant. Place the model as far as possible from the front, where the bed is likely to be a bit colder.
Unless it’s strictly necessary for strength reasons, keep the infill percentage under 30-35%.
Yeah, see there are these rather large holes near the front, smaller holes all around, and of course the area behind the extruders is wide open.
We have tried with the fan off and cranking up the temps. We can try moving the model to the back as much as possible, but it is large enough that it won't get us too much.
The original model for the pictures above was I think 40-45% infill. We are now doing tests that would keep the infill to maybe 20-25%, but increase the wall thickness all around to maybe 4 layers or so, which appears to have a greater impact on strength than infill density up to a point.
-JCL
RE: Large multi-day print warping (Printing with Polycarbonate)
PLA will hold 25lb no problem at all. If you research the actual strength of the materials you'll be surprised to see that PLA is very strong. The compressive strength is very close to PC.
You can keep trying to print PC, but PLA will give you a much better finished part.
Good luck.
RE: Large multi-day print warping (Printing with Polycarbonate)
Warping is the nature of the beast with fdm in general, and the higher the required printing temperature, the larger the parts, the worse it'll be.
Yeah, I guess we got a little overconfident with all the great printing we have had with PLA and PETG, we were spoiled.
The warping is caused by the unequal cooling of the plastic. As plastic cools it shrinks. So the further you get from the heat bed the faster it cools. Corners cool faster than the rest of the part, which is why corners typically curl up. Rounded corners because they have more mass cool slower than square corners so a radius is better if possible.
We can try rounding the corners "more" but we are already using "cut off" corners. I think this would be another tiny incremental difference.
Other factors are infill, which will cool faster than solid sections, and basic changes in part geometry cool differently.
The reason an enclosure helps is because the higher you can get the chamber temperature the slower the plastic cools, thus helping with warping.
Yeah, we purchased the XL enclosure and I think had overly optimistic expectations. We mainly bought it to be able to print in ABS and PC.
While I won't say I necessarily regret buying it (yet), if there is not some trick to this that I am really missing, then I am kind of wondering what the point of the enclosure actually is. It only comes with a circulation fan and air filter unit, it is not temperature controlled, and it is about as well sealed as a barn. Maybe we are just missing whatever the ideal use case for this particular enclosure setup is, maybe it is not PC.
We were chatting with Prusa support, and the guy we talked with actually sent pictures of a part he printed in PC, no enclosure, just using a draft shield/skirt. The part he was printing was a fair bit smaller. We were not able to come near his results, even on much smaller test parts.
In order to get minimal to no warping you would need an industrial printer that can have chamber temperatures from 60 to 90°C, which your never going to get with our hobby printers.
Yeah, see I wish this was more clear before deciding to get the enclosure. The new CORE One claims no warping, and has a chamber temperature up to 55°C, still not near the 90°C you are talking about. But it does have a temperature controlled chamber.
That being said things you can do to help include rounded corners, brims, maintaining constant part thickness where possible, avoid big thick sections of possible, and higher chamber temps (there's a limit to what we can do here with our printers. I wouldn't go much more than 40° - 45°C or you'll start having other issues).
The particular print we are doing is breaking most of these rules, unfortunately.
I'd also consider making your part from PLA if it's going to be inside your house. PLA will warp much less than PC and will be plenty strong. Plus PLA prints really nicely. If you use PLA be sure to use the PEI print sheet as PLA sticks much better to that.
Good luck.
While I can't say for sure if PLA would be strong enough in this use case, we have our doubts. If you look at the numbers, obviously PC has way higher tensile strength. We don't want the speakers to fall on someone. And of course, if we just print it in PLA, we kind of feel silly getting the enclosure.
I am starting to wonder how hard it would be to do a "mod" of this printer to improve on this. Basically take as much of the electronics out and power supplies and locate them remotely so they don't overheat, then seal up (or even insulate) the chamber "better" and add a heater/thermostat to the circulation fan setup so that we could reach and maintain higher enclosure temperatures. I could cannibalize a filament dryer to get the parts to do that I think. I don't know if all of that would make a difference or not. I was thinking of asking someone at Prusa how much heat the electronics/power supplies/extruder heads could take, maybe if we just added enclosure temperature control with a heater that would do it. Maybe they will come out with an upgrade in the future, considering the CORE One has this feature already.
-JCL
RE: Large multi-day print warping (Printing with Polycarbonate)
Here are some results from our various tests:
You can see the "super brim" on this last test at the end, it worked OK. But, the problem is will it work on a much larger model?
One idea we have, other than the others mentioned here already, is to divide the part up into sections in Prusaslicer, print them individually, and then glue them together afterward either with solvent to weld the parts together, or epoxy.
-JCL
RE: Large multi-day print warping (Printing with Polycarbonate)
PLA will hold 25lb no problem at all. If you research the actual strength of the materials you'll be surprised to see that PLA is very strong. The compressive strength is very close to PC.
You can keep trying to print PC, but PLA will give you a much better finished part.
Good luck.
OK, I will consider that. I suppose for one thing, with PLA we could make the part very beefy, say much thicker walls 4-6 layers, and maybe use 25% infill with 3D honeycomb.
RE: Large multi-day print warping (Printing with Polycarbonate)
Unfortunately, PC and other materials in this bracket of strength will always have a higher shrinkage factor to overcome, which is the main problem you're always going to face. An enclosure is designed to help, but is not the magic bullet. As you've seen, getting the best bed adhesion as possible is the only real way to overcome it without going to a heated chamber.
That said, have you considered using PCCF? You'll sacrifice a bit of the toughness (always the case with CF, as it inherently makes parts more brittle), but the CF infill allows you to print it with essentially zero warpage.
RE: Large multi-day print warping (Printing with Polycarbonate)
I totally agree. CF filled filaments warp a lot less than the plain versions. I haven't tried Polycarbonate PC-CF, just Prusament PA11-CF and I like it a lot. Almost no warping, great strength and nice finish. Probably it has better interlayer adhesion and it's less britlle than PC-CF but I reckon that both filaments are strong enough for that speaker mount.
RE: Large multi-day print warping (Printing with Polycarbonate)
Unfortunately, PC and other materials in this bracket of strength will always have a higher shrinkage factor to overcome, which is the main problem you're always going to face. An enclosure is designed to help, but is not the magic bullet. As you've seen, getting the best bed adhesion as possible is the only real way to overcome it without going to a heated chamber.
We are printing one now where we divided the part up into four parts, we are printing it near the back of the printer, using a large brim, a draft shield, and glue. We also went to 5 layer walls and 20% infill with 3D honeycomb. It is almost done, fingers crossed that comes out better. I will glue the four parts together with probably epoxy, but I could try solvent.
That said, have you considered using PCCF? You'll sacrifice a bit of the toughness (always the case with CF, as it inherently makes parts more brittle), but the CF infill allows you to print it with essentially zero warpage.
Actually, I did not know this about filament with CF in it. Now that you mention it, I did some searching and reading, and apparently the reduction in warping is enough that you can sometimes not even use an enclosure. That seems like a big difference.
It's WAY more expensive, but it seems like it would be worth trying out. I am going to take this with a grain of salt though, because I ordered some Prusament PC filament and it warped even (allot) more than the cheap stuff at my local Micro Center. Going to see what they have for CF filaments too.
Actually, online there seem like a few good choices of CF filament that is very low warping.
Thank you very much for the tip.
-JCL
RE: Large multi-day print warping (Printing with Polycarbonate)
I totally agree. CF filled filaments warp a lot less than the plain versions. I haven't tried Polycarbonate PC-CF, just Prusament PA11-CF and I like it a lot. Almost no warping, great strength and nice finish. Probably it has better interlayer adhesion and it's less britlle than PC-CF but I reckon that both filaments are strong enough for that speaker mount.
Yes, I think this is definitely worth exploring.
I was considering the PLA idea, but I keep hearing that it will warp over time even in a "warm" room. Not sure if that is legend or truth, but it would be bad because the speaker mount needs to maintain a certain angle, and as I mentioned, I wouldn't want it coming off and hurting someone. Better off paying for CF filament if that is what it takes.
Thanks for the tips. I will post updates on my progress.
-JCL
RE: Large multi-day print warping (Printing with Polycarbonate)
Firstly I have not had issues printing flat area with PCCF. Also I don’t think you say what polycarbonate you are using. The Prusa version supposedly is good for non warping.
I wonder If reducing the continuous surface area on the bed would help by adding a few narrow grooves
i3 Mk3 [aug 2018] upgrade>>> i3MK3/S+[Dec 2023]
RE: Large multi-day print warping (Printing with Polycarbonate)
You can also use an ooze shield to keep the Temperatur more stable
RE: Large multi-day print warping (Printing with Polycarbonate)
[...] It's WAY more expensive, but it seems like it would be worth trying out. I am going to take this with a grain of salt though, because I ordered some Prusament PC filament and it warped even (allot) more than the cheap stuff at my local Micro Center. Going to see what they have for CF filaments too.[...]
PC filaments are going to vary between brands (and even within brands) wildly, due to the fact that PC filament is never 100% PC. It's always a blend of some sort. From my own experience with Prusament PC, I agree -- it warps like crazy compared to others... but it's not the worst -- that title goes to 3DXTech's 3DXMAX PC. Which is ironic, because they also make ezPC, which is by far the best behaved PC I've tried, hands down.
Unfortunately, this trend of variance between brands also carries over to PCCF. BUT -- if you manage to catch Prusa when their PCCF is actually in stock, it's arguably the best around, and the price is extremely competitive. Be warned -- stock runs out within the day that it's added.
RE: Large multi-day print warping (Printing with Polycarbonate)
Thought you might find this interesting