Prints acting as heatsink and corners curling
Hello all. I have been having trouble with corner curling for a while, and while increasing my heatbed temperature has helped, I still get a little bit of curling even with brims and mouse ears (when you flip the print over you get little Y shaped pullups at each corner where the brim partially did its job.
I currently print with the bed at 70 degrees with PLA and I was starting to get concerned that the temperature might not be accurate, so I got a decent thermal measuring device and I realize now what the problem probably is.
My prints are acting like a heatsink! --- ok that should have been obvious, but the problem is that the heatbed is not warming up to compensate. The edges of my heatbed will be 70 to 71 degrees, but the areas right next to the print can be as low as 58. I believe that if I can get that temperature up to 65 or 70 and keep it there throughout the print I can get rid of this last bit of corner curling.
Any other ideas I should try aside from jacking the heat another 5 degrees ?
Prusa Mk3 with powder coated bed that has been scrubbed, cleaned, loved, and provided copious amounts of pure grain alcohol to protect its precious essence.
(FYI -- my first layer is as tuned as it is ever going to get -- I am fairly certain I am losing adhesion due to the parts acting like little heatsinks after this thermal measurement discovery --- and I am trying to make it work without using any adhesive ... it is like a matter of a pride at this point 🙂
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Re: Prints acting as heatsink and corners curling
You're printing with PLA? I have a couple of questions/comments...
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Re: Prints acting as heatsink and corners curling
1) Bed adhesion seems to be strongest on the powdercoated sheet at around 60+ C --- I thought my bed was underheated as referenced in original post so I walked it up and general bed adhesion is rock solid now until the plate cools and the different shrinking speeds pops it right off
2) Yeah you definitely need some heat to keep the PLA on the powder coated sheet if oyu don't want it to shift
3) Not really needed -- adhesion is pretty rock solid at the moment
4) I am trying to solve this without adhesive, as stated in the original post -- it is a matter of pride because brim or mouse ears should be enough to stop this
5) My gun has a dual laser system so you know exactly what circle you are measuring. the build plate itself is reading a surface temperature much lower near the parts, and it is a fairly nice curve away from it... 60 61 62 63 64 65 ... etc using very small measuring diameters (about a half a to a 1 centimeter circle) I have also tuned the gun for the heat emissivity of the powdercoated plate and it registers correctly ambient room temperature when cool.
Re: Prints acting as heatsink and corners curling
3) Not really needed -- adhesion is pretty rock solid at the moment
4) I am trying to solve this without adhesive, as stated in the original post -- it is a matter of pride because brim or mouse ears should be enough to stop this
Sorry, but I don't understand that. It's like not using the right tools for your job.
I've for example red Matterhackers PLA roll. This one has exactly the same problem. So I'm using very fine abs film for this filament. Problem solved.
I suggest you either use adhesion helper (whatever you prefer) or get other filament brand. Playing with bed temperature will just bring you other problems.
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Re: Prints acting as heatsink and corners curling
As an experiment I have given it a quick acetone wipe, followed by a rinse with distilled water, then 99% alcohol rinse, lint free wipe with clean cloth, and will know in 8 hours if I have a different result.
Re: Prints acting as heatsink and corners curling
I think that the part should act as an insulator to help hold the temperature. Maybe it is the cooling fan that is removing all the heat.
Steve
Re: Prints acting as heatsink and corners curling
As an experiment I have given it a quick acetone wipe, followed by a rinse with distilled water, then 99% alcohol rinse, lint free wipe with clean cloth, and will know in 8 hours if I have a different result.
More reliably - a drop of dishwashing detergent wiped with a wetish paper towel and then cleaned off with water and dried - NO fingers!
i3 Mk3 [aug 2018] upgrade>>> i3MK3/S+[Dec 2023]
Re: Prints acting as heatsink and corners curling
As an experiment I have given it a quick acetone wipe, followed by a rinse with distilled water, then 99% alcohol rinse, lint free wipe with clean cloth, and will know in 8 hours if I have a different result.
More reliably - a drop of dishwashing detergent wiped with a wetish paper towel and then cleaned off with water and dried - NO fingers!
Dishwashing detergent - that is part of my standard ritual.
Ok -- after action report --
acetone appears to have had an effect. The corner tips are no longer getting slight curling, so bed adhesion was improved greatly. I am still getting very odd temperature readings near the parts.
I am going to do another print tomorrow and intentionally print near the bed corner to see what happens.
Re: Prints acting as heatsink and corners curling
I think that the part should act as an insulator to help hold the temperature. Maybe it is the cooling fan that is removing all the heat.
Steve
You may be right. And the bed is not trying to heat back up because the heating bed is probably still very toasty even though the very surface of the powdercoated plate has become not so toasty.
Re: Prints acting as heatsink and corners curling
I think that the part should act as an insulator to help hold the temperature. Maybe it is the cooling fan that is removing all the heat.
Steve
You may be right. And the bed is not trying to heat back up because the heating bed is probably still very toasty even though the very surface of the powdercoated plate has become not so toasty.
Re: Prints acting as heatsink and corners curling
I am giving butterworth answer credit since acetone did work to solve the curling. The temperature readings are still confusing to me -- but the actual printing issue was solved by bulletpoint number 3.
Re: Prints acting as heatsink and corners curling
Rock on. Happy printing!
MyMiniFactory (Functional Parts and Mods): https://www.myminifactory.com/users/butterworthdesign
Thingiverse (Fun Designs and Remixes): https://www.thingiverse.com/uscbutterworth/designs
Twitter: @USCbutterworth https://twitter.com/USCbutterworth