Opportunity is missed by most people because it is dressed in overalls and looks like work. - Thomas Edison
There is no real way to test this unit without running a long DC job on them when we're finished exposing them for 5 seconds or whatever the time is because I've seen it so many times, a screen looks fully developed and shows no signs of underexposure until you're 50 shirts into a DC print.
OK, those throwing with numbers of 3, 5, 10, 12 seconds made me think a bit.Is there really an advantage of having a exposure unit that will save you 4 seconds per screen, even if you are making 100 of screens per day?That is 400 seconds which is less that 7 minutes per day if you do 100 screen per day, and there is only a few of people here that do that regularly. (Maybe)My biggest concern is a margin of error in the 3 or 5 seconds exposure time.I have Nuarc 40-1K and takes me about 80 seconds to expose a screen. I expose one, wet it, get the new screen out and put it in exposure unit, wet the first one again, start exposure, wet the first one again, wait a bit, wash out. By the time I wash out the first one, second one is exposed. Even if I mess up a bit with exposure times, i'm still OK with slightly overexposed screen. But if you overexpose a screen with this unit by a .25 of the second, you are screwed. And, after 4-5 minutes you will have 20 screens exposed and none of them will be washed out, or if you have two people working, you might have 3-4 washed out by the time you expose 20.I would like to have better exposure unit, and maybe expose the screens in 30 seconds, but to me, I do not see the benefit of exposing a screen that fast. I understand a benefit of saving time exposing, but unless you can was out that fast, what is the benefit? Except maybe say that you have a machine that can expose a screen in 3 seconds.Just thinking out loud
Rich, did you guys build a standalone, contained pressure washing unit? I've always thought that would be perfect to have a couple of those in the wet room instead of blasting water and chem vapor everywhere with a press washer.
Excellent. One of your boys is stopping by tomorrow, I'll be sure to request some pricing.
I just got through developing and analyzing the 5 screens I burned with the Vastex unit. I know this won't matter to a good many of us but this is what I did with what I had. HVP, pure photopolymer without the diazo added to it. We've found the HVP to burn almost exactly like all the other PP's that we've tried. These were all coated with the glisten method and had around 15-20% EOMR. I can get exact emulsion thickness numbers if anyone really wants them but just know these screens weren't thick by any means, but they weren't the bare minimum stencil either. I did the 305 at 10 seconds, 230 at 15, 195 at 15, 156 at 20 and the 110 at 30 seconds. The 156 and 110 were noticeably underexposed. The 305 sprayed out nicely and showed no signs of underexposure and the 230 and 195 also came out looking great. Our bulb is older now and when it's new, a light unit is about 5-6 seconds, now it's about 12-15 seconds per unit so when comparing exposure times with an aged bulb, the LED is significantly faster. Now for the quality and stencil edges: I don't know if I'm just tired and couldn't get into looking through a loupe for an hour but I couldn't find any blemishes on the LED screens. Besides the usual underexposure problems that you see, there was really no difference between the 305 I burned with the MH unit versus the LED. They both looked fanstastic and held the same percentage dot and the edges were as crisp from screen to screen. I will look at these again in the morning to see if I find anything of significance on the LED screens but I don't think I'm gonna find anything that will matter to any of us, even those guys who are entering competitions.So I guess I'll eat some crow. After my first test, I didn't think the LED would perform as good as a 5K and up MH bulb, but after these 5 screens, I am proven WRONG. More to come later as I think of it or if anyone has any questions on my little testing session today. I'll also look at the screens again in the morning with a fresh mind.
Pierre, if someone had a MH unit (msp3140) do you think they would see enough advantages going LED to make it worth it? I've been tempted to upgrade my old fluorescent unit (Nuarc first light). Rich, will M&R also have an upgrade kit for fluorescent units?
Quote from: alan802 on October 14, 2013, 05:52:38 PMI just got through developing and analyzing the 5 screens I burned with the Vastex unit. I know this won't matter to a good many of us but this is what I did with what I had. HVP, pure photopolymer without the diazo added to it. We've found the HVP to burn almost exactly like all the other PP's that we've tried. These were all coated with the glisten method and had around 15-20% EOMR. I can get exact emulsion thickness numbers if anyone really wants them but just know these screens weren't thick by any means, but they weren't the bare minimum stencil either. I did the 305 at 10 seconds, 230 at 15, 195 at 15, 156 at 20 and the 110 at 30 seconds. The 156 and 110 were noticeably underexposed. The 305 sprayed out nicely and showed no signs of underexposure and the 230 and 195 also came out looking great. Our bulb is older now and when it's new, a light unit is about 5-6 seconds, now it's about 12-15 seconds per unit so when comparing exposure times with an aged bulb, the LED is significantly faster. Now for the quality and stencil edges: I don't know if I'm just tired and couldn't get into looking through a loupe for an hour but I couldn't find any blemishes on the LED screens. Besides the usual underexposure problems that you see, there was really no difference between the 305 I burned with the MH unit versus the LED. They both looked fanstastic and held the same percentage dot and the edges were as crisp from screen to screen. I will look at these again in the morning to see if I find anything of significance on the LED screens but I don't think I'm gonna find anything that will matter to any of us, even those guys who are entering competitions.So I guess I'll eat some crow. After my first test, I didn't think the LED would perform as good as a 5K and up MH bulb, but after these 5 screens, I am proven WRONG. More to come later as I think of it or if anyone has any questions on my little testing session today. I'll also look at the screens again in the morning with a fresh mind.Can you expose some linearized 55 and 65 lpi screen halftone screens? I am waiting for someone to share that info.......