3D Printing Forum

There seems to be lots of on-line advice on reducing sticking to the FEP film, and to avoid the model separating from the build plate, but there must also be a danger of the model breaking in the middle if it is too skinny (small in cross section) comparted to the FEP contact area which resists lifting. As a new user of these printers I am surprised how much the FEP film is gripped, and indeed my first model was pulled off the build plate due to contact area there being too small. But I fixed that by widening the initial build surface.

Is there some sort of ratio of FEP contact to model cross section that can lead to breaking in the middle? I am particularly thinking of making window frames (about 25 x 40 mm and 5mm square in cross section). The frame could be formed flat against the build plate but that limits the number to made together. But if they hang vertically from the build plate, when the bottom horizontal member is being formed there will be a large FEP contact area but a small cross section of the two vertical members. If this is likely to cause a break then remedies could include addition vertical rafts between the top and bottom members or forming it on an angle so there is never a whole length of a straight member being formed at once. Although in that case extra support rafts would be needed at the top, and the FEP pull would tend to distort the rectangle.

Hi and welcome to 3D resin printing.
There are a few guidelines you need to know.
Supports, I always let the software generate supports then I add more is areas I think are needed.
If you plan on putting the part flat on the buildplate make sure it doesn't have a cavity that has trapped resin as the suction will cause problems. Think of a cylinder stick up, you need to add drain holes where it meets the buildplate so the resin drain.
If you need to have supports underneath the part, put the part on an angle, say 45° as this will reduce the print area and you can get more supports on the model.
Have a look at some youtube videos of people using resin printers and see how they put the model in the printer and also how many supports they have.
You will pick up knowledge the more you print, just don't try and run to start with.
Good luck
Lez