ABS not warping up on edges but bulging up in the middle!
Hello. I'm trying to print a part from https://www.prusaprinters.org/prints/5928-prusa-mk3s-einsy-raspberry-pi-4b3b-enclosure-with- from ABS but I'm experiencing a strange problem when the middle of the print is bulging up constantly.
I've also attached 3mf with settings from my last try.
I've tried no fan and also 15% always on fan and also tried to slow down everything to max 40mm/s.
First I thought that my heatbed was warped ( https://forum.prusa3d.com/forum/original-prusa-i3-mk3s-mk3-hardware-firmware-and-software-help/bulging-bed-when-heated/) and it really was but I've fixed it since (down to <0.1mm when heated) and even before the variance could not account for such huge bulge as on the picture above.
Any ideas what else to try?
Thanks
Title here
Are you printing in an enclosure? If not, you might try the draft shield option, available in both PS and Cura. This will give you a more consistent temperatue.
Are you using anything as a release agent/adhesion booster?
It's been my experience that, if anything, ABS sticks much too well to the plate? Something like Layerneer, Magigoo, ABS Juice or even glue stick will assure an even adhesion and easy release.
.
@jsw: I'm printing in an enclosure and Einsy reports stable ambient 55-60C during print.
No I'm not using any goo, just ordinary smooth PEI sheet. I have no problem with adhesion... it seems that the print warps the whole steel sheet with it.
Btw. I completely fail to understand what would lowering the adhesion achieve...
I'm just guessing, but if your trying to pop that off the plate right after or soon after it's done printing you can have this issue. with ABS and several other filaments, its best to do a slow controlled cool down and not pop the part off the bed, wait for it to release. beyond that wait for the inside of the print to cool as well.
If its releasing and bowing up during printing, and your sure you build surface was clean then you most likely have a cooling issue.
Good Luck
Swiss_Cheese
The Filament Whisperer
RE: It says to insert title here, so I am.
I ruined one side of the plate that came with the printer by not using a release agent and getting impatient and using a kitchen implement to (try to) pry the (ABS) print loose.
I've done many ABS prints, and I always do the following, as ABS cannot take a joke as well as PLA does.
1. Pre-heat the machine to ABS temperature and let it and the enclosure temperature stabilize. I try for at least 20 minutes if coming from a cold start.
2. Use a release agent. I usually use Layerneer. More consistent adhesion and easy release.
3. Let the print cool to almost room temperature before attempting removal.
I've done many flat ABS pieces (many roofs of my model RR buildings are black ABS) with no warp issues at all.
I learned to print at our local 'makerspace' and I was used to glass plates that required a certain degree of 'gentle persuasion' to release the print. ('OK, get out the air hammer.') 😉 Razor knife or a spatula was often necessary. I tried the spatula on one of my first ABS prints on the Prusa, and a few pieces of the coating came off with the print.
I'm just guessing, but if your trying to pop that off the plate right after or soon after it's done printing you can have this issue. with ABS and several other filaments, its best to do a slow controlled cool down and not pop the part off the bed, wait for it to release. beyond that wait for the inside of the print to cool as well.
If its releasing and bowing up during printing, and your sure you build surface was clean then you most likely have a cooling issue.
Good Luck
Swiss_Cheese
1. It does NOT loose any adhesion during print. I had thought that it was bowing up with the steel sheet basically overcoming the magnets in the middle but a few minutes ago I found out that I was wrong. I tried printing it again (this time from PCTG) and just before the printing finished I checked that the print surface is not bowed up using a piece of Al extrusion (couldn't find a ruler) and flashlight.
2. I always wait for the bed to cool down to around 40C (and the inside of the print couldn't be much higher than few C above that) before taking it off. It release by itself and once the adhesion goes only then it bows up or so it seems. It has to have a lot internal tension "printed in".
3. I sawed it in half to expose a cross section a the horizontal bulge looks magnificent 😀
I'm contemplating trying it printing from PETG with the same settings.
Middle of print raised after print
I have the same problem (but to a slightly lesser extent) with large, flat PLA and PETG prints. Everything adheres nicely and stays flat until I remove it from the sheet and then I notice that the centre is raised. I am running a nine hour print right now after spending this morning implementing the Nylock mod but I bet it will be the same!
1
If I print a square box, then warping will come very fast, in the corners it will warp, check your model if in the middle it has the same problem like a corner.
You could try to print with higher temperature.(check on filament)
Print slower so print can cool down before next layer comes.
Use no fan with ABS.(use only fan if print is very small and the model gets to hot.)
Inside a printer enclosure, a mk3 printer will only work at 40 degrees(or lower), higher is not good, because the extruder will get to hot and cooling will not work anymore. Leave door open if it is to hot, and use a draft shield.
.
I have the same problem (but to a slightly lesser extent) with large, flat PLA and PETG prints. Everything adheres nicely and stays flat until I remove it from the sheet and then I notice that the centre is raised. I am running a nine hour print right now after spending this morning implementing the Nylock mod but I bet it will be the same!
How it went?
Enter title here
The centre of my 9-hour print still warped up slightly after I removed it from the sheet but not as much as the same model (printed with the same material) prior to the nylock mod. So a bit inconclusive really.
The theory for my problem is/was that perhaps the Prusa bed levelling system (Pinda etc) making corrections for a warped print bed could have introduced some stresses in the printed object that cause this warping issue during cooling and only become evident after removal from the print sheet?
I have the same problem (but to a slightly lesser extent) with large, flat PLA and PETG prints. Everything adheres nicely and stays flat until I remove it from the sheet and then I notice that the centre is raised. I am running a nine hour print right now after spending this morning implementing the Nylock mod but I bet it will be the same!
How it went?
RE: .
@jsw, @swiss_cheese I do NOT have any problems with bed adhesion or releasing after printing. And I always wait until the bed temp is under 40C before I even open the enclosure (except for PETG which I print with opened enclosure). My prints always hold like glued with supeglue when the bed is hot and almost always release by itself when the bed is cool. Please stop recommending solutions to problems I'm not looking to solve because I do not have them.
Btw. even PETG bows up in the center:
20210727_141242
Having seen your video - I am sure that this is my problem too. It appears that you and I are the only two people that have this problem.
Perfect adhesion during the print and no warping during print. Take it off the bed after it has cooled and the damn thing warps up in the middle.
I wonder if we could find someone else with say Prusament PETG and a MK3 that would be prepared to print your gcode? We could all print the same g-code (with similar filament) and then compare the results. We could see if the problem only appears on your print and my print.
Just an idea.
RE: ABS not warping up on edges but bulging up in the middle!
I haven't tried ABS, but I do have the exact same problem with PETG. For instance, if I print a 120mm diameter disc 4mm thick it will be perfectly flat on the plate when finished. However, when it is off the plate it will be bowed upwards in the middle.
I'm thinking it is differential contraction of the filament when cooling. The layers near the bed have limited contraction because of bed heating while upper layers are not heated so much and therefore contract more. Everything is held flat by bed adhesion, but when separated the lower layers complete their contraction, thus pulling in the sides at lower levels and causing the upwards bowing.
If I can get good bed adhesion I might try reducing the bed temperature as much as possible to limit the temperature v. height differential.
RE: ABS not warping up on edges but bulging up in the middle!
If I can get good bed adhesion I might try reducing the bed temperature as much as possible to limit the temperature v. height differential.
Let us know how it goes!
RE: ABS not warping up on edges but bulging up in the middle!
"I might try reducing the bed temperature as much as possible to limit the temperature v. height differential"
I'm pretty sure that I tried this (within reason) but I don't think that it helped.
In the end, the only solution that I ever found for my PETG prints that warped up in the middle slightly after cooling was to anneal the prints in my drier with a small amount of weight on them.