Re: Help! Holes!
Posted: Fri Mar 20, 2015 4:15 pm
Hello.
I watched the print process on top-down carefully and I think I know what the holes are. Basicaly they are the parts of the print where due to the combination of shrinkage, fluid dynamics, speed etc that small "rivers" form in the print. It usually happens when a model has a closed circele with a very thin wall. When the model is submerged it fills with resin, like a glass. When it goes back to the surface, because of shrinkage some parts will stand on top of the liquid and some not. When most of the "circle" stands on top of the surface but very small parts "valleys" don't, the resin caught inside the circle will try to flow outside through the small valley. And it will flow with much higher speed because of big volume of resin trying to escape through a small hole. So the small ammount of light that is casted on that "valley" will not be enough to cure the speeding resin.
Solution :
-Reduce shrinkage (makerjuice has huge shrinkage rate for instance and it's better for objects that are full of holes by design. I
-Leave more time for the resin to settle before beaming.(can anyone tell me where I change the value in CW ? for that ?)
-It happens mostly on hollow models (like the examples here). Make the wall thickness bigger.
I watched the print process on top-down carefully and I think I know what the holes are. Basicaly they are the parts of the print where due to the combination of shrinkage, fluid dynamics, speed etc that small "rivers" form in the print. It usually happens when a model has a closed circele with a very thin wall. When the model is submerged it fills with resin, like a glass. When it goes back to the surface, because of shrinkage some parts will stand on top of the liquid and some not. When most of the "circle" stands on top of the surface but very small parts "valleys" don't, the resin caught inside the circle will try to flow outside through the small valley. And it will flow with much higher speed because of big volume of resin trying to escape through a small hole. So the small ammount of light that is casted on that "valley" will not be enough to cure the speeding resin.
Solution :
-Reduce shrinkage (makerjuice has huge shrinkage rate for instance and it's better for objects that are full of holes by design. I
-Leave more time for the resin to settle before beaming.(can anyone tell me where I change the value in CW ? for that ?)
-It happens mostly on hollow models (like the examples here). Make the wall thickness bigger.