Resin (smoking)

You can discuss Photo-sensitive resins, polymers, and oligomers.
technut09
Posts: 1
Joined: Mon Jun 29, 2015 5:06 pm

Resin (smoking)

Postby technut09 » Mon Jun 29, 2015 5:13 pm

Hi Team,

First time poster here. I just built a top down system and was printing with a 3000 lumen un modified BenQ projector at a distance of about 18".

Strange part is that if I expose for 12 seconds+ Using only maybe 1/10 of the projectors full image (small part on large projector screen) I can get the resin to almost crystallize/smoke/steam? When the layer is exposed it looks to almost heat up and microscopically sizzle then steam comes out of it were its brightest white. I tried shorter times but it seems the resin wont cure.

Has anyone ever seen this? Its MarkerJuice G+ Black at 0.1MM layer thickness. My "best" guess is that the projector is pushing out a lot of radiant heat and not enough UV light? I tried to modify it but the projector UV Glass plate on the bulb protects the light tube from overheating and without the glass there it will overheat and shut down on its own.

Thanks,
-Steve S. :idea:

FR3Dprint
Posts: 18
Joined: Tue Dec 16, 2014 4:20 pm

Re: Resin (smoking)

Postby FR3Dprint » Tue Jun 30, 2015 7:35 am

Seems that your problem is that the energy is not properly adjusted (sorry for my English, adjusted may not be the right word).

What you can try is to set your projector closer to the resin. Say 20cm. Then print thicker slice, say 50µm. Then reduce the exposure to 3s.

What could happen in your case is that the exposed side of the slice polymerises (a skin is formed at the exposed side), and prevent the unexposed side to be exposed... that's why I say to print thicker slice. Then, with a short time, the resin don't cure. If you increase the time there is no other effect than burning the printed skin.

On my side, I'd already experiment the SUBG without modifying the projector. This did not work. Removing the UV filter seems mandatory. Try to remove it (but ccould reduce the DMD life) or try FunToDo resin, which cure OK with non modified proj.