I’ve been working on a DLP printer project, and I’ve gotten to the point where it might be a good idea to know what kinds of layer exposure times I might expect. So I loaded up a syringe with Makerjuice that was lying around from gosh knows when, squirted a couple drops on a piece of glass, and ran it in front of my projector. The last time I bothered to read up on this, people were talking 30 seconds and up per layer. This was fast. Which is good.
So there I was with the rest of a syringe full of Makerjuice. And a UV flashlight on the shelf somewhere. I decided to see what would happen. As you can tell from the picture, when the tip of the syringe was in the center of the beam the resin cured as fast as I could squirt it out. In fact, I got a sort of lava-tube effect, where the cured resin shielded the stuff coming out of the syringe until it reached the end of the tube and got exposed to light, making more tube and so forth.
I know that actually trying to print with this stuff would be well-nigh impossible — the shrinkage, the smoke, the smell — but it’s interesting to think about how you might do it. You’d need a very fine syringe, and shielding so that the UV never actually touched the extrusion tip, and UV-proof visible parts for the whole machine. Or maybe just a resin with different viscosity and curing properties… Eh. The whole point of DLP is making something that can speed you up by printing a whole layer at once, so it’s probably not so bright to figure out ways of making the process really slow.