After successful printing, the model crack after a certain period of time. Common reasons are as follows：
1）The layer thickness value is too large, and the ultraviolet light cannot penetrate completely, resulting in incomplete adhesion between the layers and the presence of gaps, leading to model cracking. It is recommended to use the default settings for the layer thickness value.
2）Normal exposure time is insufficient, resulting in incomplete solidification of the model. It is recommended to increase it by 0.5s.
During slicing, only the shell is hollowed out, and punch is not performed, resulting in excess resin inside the model that cannot be removed, causing differences in internal and external pressure and leading to cracking. Therefore, after hollowing out the shell, it is necessary to punch the model to remove excess resin.
1）After punch the model, if the inside is not washed thoroughly, cracking may occur.
2）During model washing, if the resin dissolved in the washing solution reaches saturation, excess resin will adhere to the model surface, resulting in differences in internal and external stress, and possible cracking. It is recommended to wash the model again using a clearer washing solution after the first washing.
3）If soaking time in water or alcohol during cleaning is too long, cracking may occur because alcohol can soften the resin. This is especially true for hollowed-out and punched models.
1）Lack of Secondary Curing: The first curing of the model only occurs on the exposure plane, as the model's vertical edges are not exposed to the light source, resulting in incomplete curing of the model's surface. Over time, this may lead to issues such as cracking. Therefore, secondary curing of the model is necessary.
2）During the secondary curing process, the model must be uniformly exposed to ultraviolet light. Otherwise, the model may experience cracking and deformation due to differential shrinkage at different locations. It is recommended to use a Wash&Cure machine for secondary curing.
If you have recently changed to a different type of resin, it is recommended that you consult the resin manufacturer to see if any adjustments to the printing parameters are necessary.