multi-layered VAT caused too many reflections
Posted: Tue Oct 28, 2014 12:00 am
Hello guys, I've been reading and learning alot from this society, very appreciate Pacman's great work. Little by little i completed my own DLP.
The VAT is built with borosilicate glass covered with unsticky .05 FEP membrane and the rest of basin is built with PMMA. DLP is H6510BD, ECO mode on to reduce the brightness, and during first loop of test , I tried curing a layer for 2-4 seconds.
Because I am based in Hongkong now, there are no easy access to resin suppliers like FTD, therefor I sourced different resin from China for test, which is very painful. and you know what, they are not cheaper.
1. The first resin I tested is yellowish transparent resin, it bleeds alot even if I set cure time to 1000ms. After I clean the basin, I found the resin around the edge are cured as you may see in the photo. I have no clue what cured these area. Did this happen to any one?
2. Take a close look at the VAT, I can see many layers of reflections of the image projected, particularly a strong projection on top layer, which I guess is FEP. is this normal? or is it because membrane or glass isn't transparent enough? will this cause bleeding to the rest of resin?
3. and in the end I did a test, I expose resin under dlp in blank, and there are still light leaks on in blank which as a result slightly cured the resin in 10-20 minutes. Is it because the resin is too sensitive? and will adding pigment help?
I wish i could understand more of these before I start another loop of tests, there are so many concepts missing in my knowledge, and I appreciate any advice or suggestion. Thank you guys in advance,
The VAT is built with borosilicate glass covered with unsticky .05 FEP membrane and the rest of basin is built with PMMA. DLP is H6510BD, ECO mode on to reduce the brightness, and during first loop of test , I tried curing a layer for 2-4 seconds.
Because I am based in Hongkong now, there are no easy access to resin suppliers like FTD, therefor I sourced different resin from China for test, which is very painful. and you know what, they are not cheaper.
1. The first resin I tested is yellowish transparent resin, it bleeds alot even if I set cure time to 1000ms. After I clean the basin, I found the resin around the edge are cured as you may see in the photo. I have no clue what cured these area. Did this happen to any one?
2. Take a close look at the VAT, I can see many layers of reflections of the image projected, particularly a strong projection on top layer, which I guess is FEP. is this normal? or is it because membrane or glass isn't transparent enough? will this cause bleeding to the rest of resin?
3. and in the end I did a test, I expose resin under dlp in blank, and there are still light leaks on in blank which as a result slightly cured the resin in 10-20 minutes. Is it because the resin is too sensitive? and will adding pigment help?
I wish i could understand more of these before I start another loop of tests, there are so many concepts missing in my knowledge, and I appreciate any advice or suggestion. Thank you guys in advance,