Postby Mattasmack » Sun May 08, 2016 2:27 pm
I'm using B9 Emerald rather than yellow, but since no one else is responding I'll jump in with my experience. The resin does require a whole lot more exposure than others I've used, like Makerjuice G+. And it seems to stick to my flexvat more as well. I scratched up my build platform with 240 grit sandpaper, but I did so before I started using the B9 resin, so I don't know if it was needed specifically for this resin.
I started with an unmodified projector (different from your model) but needed layer exposure times of nearly 20 seconds, so I removed the UV filter from the lamp and brought the exposure time down to 3 - 3.5 seconds. I generally use 2-3 times the normal exposure time for the first half-dozen layers.
I had to increase the lift distance to about 5 mm to ensure that the print would release from the vat at each layer. (With G+, the print peeled loose with a lift of 2-3 mm.) If the print fails to completely peel loose from the flexvat, it is likely to fail on the next layer.
The resin is pretty thick. I found that I need to add a delay of a few seconds before exposure on each layer to let the resin finish flowing. The first several layers need a much longer delay. I also drilled a few small holes in my (hollow) build platform to help resin flow out of the space between the flexvat and platform on those early layers.
Because the B9 resin is much more strongly tinted than some other resins, you have to make sure your platform is really up against the flexvat and levelled for the first layer. I tend to print things that have no flat base, so they are entirely up on supports and don't touch the build platform themselves. That allows me to push the platform into the flexvat just a hair to make sure there isn't a gap that would cause the first layer to fail to stick. The first several layers of the print end up distorted, but because they are just supports anyway I don't have to worry about it.
