I believe I’m now up to 11/11 successful prints in a row (all different objects, by the way) – and with the hard VAT at that. Each time, I’ve been changing the exposure time lower (on layers 2 to the end layer), lowering the lift height, and increasing the lift speed.
I think there are 3 key points that are making my prints work at this point.
1. I burn the first layer (only) at 108 seconds to really harden it against the print bed.
2. I hand-modify the first layer of every print job to fill most of the print bed with strips of white (they look much like band-aids that touch the bottom of the object(s), and stretch out over the unused portions of the build plate).
3. I scratched up the build plate with 60 grit sandpaper twice, but haven’t since then. I strongly believe that this is the biggest factor in my new found success. I think it’s giving the first layer something to “grip” onto, and I couldn’t get hardly any prints to stick before this (about 1 in 5 worked before this).
I’ll probably try lowering the 108 seconds back down to 35 seconds or so, but I’m still tweaking the other layers, and don’t want to mess with what is working on layer 1.
Side notes:
1. I’m using Fun to Do Snow White resin, tinted dark gray with the black pigment they sent with the bottle.
2. I’m printing at 50 XY and 50 Z.
3. My objects have been anywhere from 68 layers at the lowest, up to 999 layers at the tallest, with most of them being around 300-500 layers high.
4. My lift speeds still go from 13 on layer 1, up to 25 on the upper layers.
5. Most of my parts are directly against the print bed. I’ve only used supports on a few parts.
Tonight’s a huge test, as I’m printing the body of a miniature cart, with a floor, four walls, and a rooftop. Hopefully these notes will help someone else who has had difficulty with their prints sticking to the print bed (e.g. falling into the resin vat and hardening on the bottom).
