I am investigating the possibility of mass-producing circular end caps (image below) for a client with tight mechanical tolerances, +0,04mm, -0,00mm on a 14mm diameter for a snap fit into a tube with matching geometry. I am using standard black resin v4 knowing it is not ideal for snap fit, but black color is a requirement, post-processing and painting is not an option. First tests made it clear that washing and curing the parts exactly the same way each time was essential for reproduciblity. Altering soak times, cure temperature and times yielded errors > 0.1mm.
So I went and bought me a Form Wash and Cure (needed them anyway). With stable settings I get 100% yield within specification, 49 caps printed in a 7x7 grid directly on the platform. It is really the only way I can be financially competitive by reducing material cost and print time. We are talking about 2000-4000 units / batch. Also time for post processing must be essentially zero, so removing supports and sanding is not an option.
Washing the parts still on the platform then letting dry completely, I remove the caps by gently tapping a sharp spatula. With this method I sometimes chip the edge of the cap, I would say out of the 49 caps 30 are good, 10 are borderline and 9 are wasted.
I need a way to increase yield before I accept this customer request. So I would appreciate any tips on removing parts printed directly on the platform without chipping the edge? Altering the part is not an option for aesthetic reasons as it is externally visible.