Resin bends during post curing


#1

I am using grey resin. When I put the 3D printed resin object inside the post cure box, the objects comes out blended.

I am using a nail spa for uv cure box. I keep resin objects for 30 mins to 1 hr. But always the resin objects comes out bended.


#2

The orientation of the model during printing can have an effect on warping in post-cure. The more “horizontal” the model the more likely it is to warp. During printing, the resin on the side of the print facing the bottom of the resin tank sees more exposure than the side facing the build platform. If I have a print I think is likely to have this problem I leave the supports on it for post-cure and remove them afterwards. That’s always more work because the supports don’t come away as cleaning once cured. But this usually helps.


#3

“During printing, the resin on the side of the print facing the bottom of the resin tank sees more exposure than the side facing the build platform.”

I didn’t get this. How does it affects warping?

Thank you for helping out.


#4

We are using only raft for experiment purpose. We haven’t really used the object.


#5

Really I all depends on the part. Depending on how the supports are arranged and how the the part is oriented it can create internal tensions which will cause the part to bend, especially if the total part size vs average thickness ratio is high.

One rule of thumb is that leaving the supports until the part is cured will help, but I recently had a bending issue on long, thin parts which had a very asymmetrical support arrangement and the supports were actually making the part bend during post-processing.

Making sure your part cures evenly during post-processing is also important. Using a turntable to ensure all faces are evenly exposed to UV light and that the eventual heat you are adding to reach 60°C.


#6

If a part is long and thin it’s pretty much impossible to get it cured without warping. Make sure to keep the part attached to the supports and also make sure that it doesn’t get too hot since heat will make it bend worse


#7

The resin changes size a little as it cures. Shrinks. If one side of the print is slightly more cured than the other side, when you post cure the print, assuming you cure uniformly, the slightly more cured side will shrink less than the slightly less cured side. If the print was straight before you post cured it, it’ll be bent when you’re done.


#8

I’m having this issue as well with Grey resin. It’s definitely happening post cure as it looks perfect coming off of the printer. The problem with leaving the part with the support structures on while curing it is that the support structures are so dense that I don’t believe the UV light will penetrate into the part sufficiently enough. I’m wondering if anyone has tried curing the parts at a lower temp and/or shorter time after experiencing warping?


#9

What about placing the object under direct sunlight? Sunlight cures not so aggressively the resin and cures it in depth. Leave the part for a day near the window under direct sunlight and then place in the cure box to maximise the strength.