Some guides to resin-printing technical details

Shell

Shell is a great tool to save resin. Here in Fusion:

 

Print orientation

It is generally recommended, looking at the internet to have models in some slanted angle when printing. This is good to get fairly flat surfaces. However, if you want a really flat surface, it can sometimes be advantageous to print with that flat along the vat. This is however quite tricky. You cannot expect the surface on the print plate to have correct anything since the first few layers have to much overexposed to get good adhesion to the print plate. My software does not even allow me to use the regular exposure on the first 2 layers. Thus, you have to be able to live with those layers being wrong. One way to reduce the issue is to have a chamfer on edges that touches the print plate:

 

The last surface on the print can then be very flat which can be useful in some cases. It should however be note that that surface must have a resonable thickness and/or good support to not warp/wobble. You also need to rinse it carefully after exposure to get a proper flat surface. You should not place these surfaces on a support, then you will get very poor results. E.g.:

 

Holes

It is hard to get good holes with correct dimensions and without left-over resin. I have not found a good method. I think ultra sonication could be a solution, but I have not tested it.

Storing printed parts

If you make pars that should fir together, such as:

 

do not store the parts together. The resin after-cures some and then the parts will stick, potentially rendering them useless and/or damaging them.

Sharp corners

Sharp corners on the build plate will experience extra rip-force during the lift phase and should if possible be avoided. In the image below, the let is a better design than the right.

Exposure settings

The part on the image below was build according to the green arrow. The part has the typical look of an underexposed part that was possibly also printed at too low temperature.