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solarbirdI've been working on getting better with annealing HTPLA with the toaster oven I have for this sort of thing, and I just got an annealed part print to match the un-annealed reference print exactly. Or, rather, to the nearest 0.1mm, which is what I can measure.
If you've never annealed a plastic: annealing raises the glass temperature, making it more resistant to heat. But it also distorts the object, typically making a 3D printed object taller and narrower. So what you do is figure out how much a given material is likely to change, adjust the model scaling accordingly, print, then anneal and hope you end up back at reference.
And I just nailed it. In a toaster oven, which is basically hard mode because they aren't the best for this, but it's what I have. Adding ceramic heat ballast is pretty key - 3.9kg of ceramic tile got the cooldown time up from 20 minutes to like an hour and a half, like a real oven, and the slow cooling is important.
The backplane did bend a bit but it does that in a real oven too, and more importantly, you can do things about that which fix it. (The copy of this object I'm using right now did that, and when snapped into place, it straightens right back up. For other objects, you'll put it in bracing of some kind before annealing. This was a freestanding anneal.)
so pleased
If you've never annealed a plastic: annealing raises the glass temperature, making it more resistant to heat. But it also distorts the object, typically making a 3D printed object taller and narrower. So what you do is figure out how much a given material is likely to change, adjust the model scaling accordingly, print, then anneal and hope you end up back at reference.
And I just nailed it. In a toaster oven, which is basically hard mode because they aren't the best for this, but it's what I have. Adding ceramic heat ballast is pretty key - 3.9kg of ceramic tile got the cooldown time up from 20 minutes to like an hour and a half, like a real oven, and the slow cooling is important.
The backplane did bend a bit but it does that in a real oven too, and more importantly, you can do things about that which fix it. (The copy of this object I'm using right now did that, and when snapped into place, it straightens right back up. For other objects, you'll put it in bracing of some kind before annealing. This was a freestanding anneal.)
so pleased
no subject
Date: 2022-06-09 12:24 am (UTC)no subject
Date: 2022-06-09 12:30 am (UTC)(But it's not terrible, like my full-speed lecture-notes bullshit. Being a transcriptive learner, I tend to learn by writing things down, and that doesn't even require being able to read it again later, so I mostly just transcribe the lecture. That is some sloppy writing. omg.)
no subject
Date: 2022-06-09 04:01 am (UTC)no subject
Date: 2022-06-09 05:14 am (UTC)no subject
Date: 2022-06-09 01:41 pm (UTC)no subject
Date: 2022-06-09 06:59 pm (UTC)(My digital caliper registers to 0.01mm but I don't trust that last digit)