Greetings,
I just received my Form Cure after several months of waiting and tried curing some parts that I had around (Clear resin,).
The parts came out severely bent (more than 0.5cm bending!) after a 60min, 60°C cure which are the default parameters for the standard resins.
Any ideas about why that happened?
Also like posted elsewhere: having no option to turn the Form Cure off or at least have the display shut off is … meh…
I don’t have a FC but I was having the same issue…
I’ve reduced the time in the IPA bath from 20 to 10mins and reduced the temperature in my home made curing oven to 30 degrees, for 60 mins. That worked quite good and the parts stay almost perfect.
I am using Black V3 and 70-90% IPA.
Also, I let the parts dry completely before going into cure.
I’ve also realized that the orientation in the build platform is important. You need to consider the peeling forces. But in this case, you see the parts slightly bent immediately after the print, before cure.
Cpinto
It’s important to note that your method drastically reduces mechanical properties. As per Formlabs measurements on standard resins, Modulus and Ultimate Tensile Strength are about 40% lower @25°C than 60°C, and 30% lower @44°C than 60°C which is significant.
We also have issues with parts bending during curing (especially with Tough), but we try to support the part better rather than lowering the temperature.
That’s right. Mechanical properties will be significantly worse.
When you say that you try to support the part better, does this really improves the results? Because I’ve had some parts bending after cure a week or two. Maybe they were not completely cured? The curing process only affects a tiny depth of the part surface area right?
Anyway, for the complex geometric shapes that we have been printing, this was the only option I found…
CPinto
My parts were printed a few weeks back and supports removed. Clearly they were dry by then 
Am I supposed to keep the supports for the curing step?
I can try that on my next print.
Absolutely, sometimes there are no other solutions, I just wanted to point out the downsides.
Yes when taking into account not only printing but also curing when orienting and placing the supports, the bending during curing can be lessen or reduced significantly. As you pointed out however, this does not apply to all parts. Sometimes we choose to remove the supports before curing if the part is better supported like that (Frew has advised to do just that, as it’s much easier to remove the supports before than after curing, but support removal isn’t the only factor to take into account IMHO).
I have the older formulation of Clear and have printed thin (0.6mm) parts that have turned out just fine
In my experience, heat at any point makes it warp, ant 60C sounds much too warm. When I printed, I had it in the IPA for 10 minutes, then I rinsed it off in room-temp water and then let it cure in UV lights submerged in water for 5 minutes (helps cure the outer surface) and then took it out of the water and dried it off and then let it cure for 45 minutes. Works just fine, haven’t tested the strength, the clear material is the more flexible of the standard materials.
That sounds interesting but nowhere in the Form Cure instructions is it mentioned that I have to cure the part in water…
Anyhow, I’ll print another part and try again.
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