LED 5000 arrived today

[Doug S]

Hi everyone,  the lawson led 5000 3248 unit was delivered today.  Of course, even being busy I couldn't wait to set it up.  I unhooked the nuarc msp 3140 and began putting the legs on the led unit.  All in all between uncrating, assembling the legs and plugging it in took me about 40 minutes.  You know how it goes, you can't wait to try the new toy out.  I had 28 screens to expose today for a big day of printing tomorrow.  18 of the screens were exposed the the nuarc.  I didn't have time to do an exposure test and probably won't have time until next week.  What I did was increase the advertised working exposures from their website by about 5 seconds "I guess I had a little doubt that it work that well".  The only emulsion I used today was Chromaline Blue and I'd coated with the 2/1 method.  I can tell you that I exposed the 150/48 in 40 seconds and the 180/48 and 230's at 25 seconds.  If I'm not mistaken they were a touch over exposed but developed fine..  There was no heat build up so my double-sided tape and the film or ink didn't stick to the back of the screens.  I always had that trouble with the nuarc although it's a great unit.  The only way I had to test the exposure today was with a white paper towel wiping the inside of the screen while I was developing them to make sure the emulsion color wasn't transferring to the towel and none of it did.

I've got some CCI wr-25 coming next week and hopefully I will have time to do some exposure testing on that as well as the chromaline blue to get accurate exposure times on the mesh counts I have with both emulsions.  Currently I have these mesh counts:  80/55. 150/48,156/64, 180/48, 230's and 305's.  I will post those results as soon as I can.

The other thoughts I have on the unit:

1.  The clamp that holds the lid down during exposure seems a little flmsy although you can adjust it to be tighter.
2.  The unit I bought is capable of exposing 2 23x31's at a time, but the vacuum blanket is fairly thick and doesn't seem to draw down as tight "although probably enough" if you are exposing 2 at once.
3.  I'm used to the 3140's lit control panel so this one seems a little cheap although it works fine.
4. The rope to drape over the screens to ensure a good vacuum isn't attached to the unit.  That seemed a little awkward.


Those negatives above aren't a huge deal to me considering the price of this one compared the the others I've seen that are the same size.

[ScreenPrinter123]

I appreciate the feedback and am looking forward to the WR25 results.  We are hoping to go LED right after SGIA to see what may be available at that time, but being able to expose diazo emulsions for WB/DC quickly is key.

[Doug S]

I appreciate the feedback and am looking forward to the WR25 results.  We are hoping to go LED right after SGIA to see what may be available at that time, but being able to expose diazo emulsions for WB/DC quickly is key.

I'm hoping to get all of my printing done in the next couple of days so I can do some real exposure testing on the wr-25 and the photo polymer.  I'm anxious as to how long it will take take to expose.  Also, I really looking forward to how much detail I'll be able to hold with halftones and fine text.

[ScreenPrinter123]

You think you will get significantly better detail than the MSP3140.  We are running an older Nuarc MH 1k unit where the light is separate from the vacuum table so your MSP is already likely faster than our unit.  If you see speed and quality advancements with the Lawson then that is all I need to hear.

[Mark @ Hurricane Printing]

You think you will get significantly better detail than the MSP3140.  We are running an older Nuarc MH 1k unit where the light is separate from the vacuum table so your MSP is already likely faster than our unit.  If you see speed and quality advancements with the Lawson then that is all I need to hear.

I have the MSP3140...I find it being pretty quick....with the new LED are we just talking about shaving a matter of seconds of of exposing time? I think the MSP is pretty quick in my mind....then again, I am not burning 30 screens a day.

[blue moon]

You think you will get significantly better detail than the MSP3140.  We are running an older Nuarc MH 1k unit where the light is separate from the vacuum table so your MSP is already likely faster than our unit.  If you see speed and quality advancements with the Lawson then that is all I need to hear.

On the tests done here, LED unit was not delivering better results then a 3140. There was an obvious albeit not a significant difference. Due to the construction of the unit light is coming from multiple directions and causing a little bit of undercutting. smallest dot we held with LED was in the 4-5% and the 3140 held the 3%. Similarly, few percent were lost on the other end.

pierre

[Sbrem]

I would say undercutting is what would concern me the most, same as tubes. Is anyone putting a tight cluster of LED's together to try to simulate a point source I wonder?

Steve

[Admiral]

I would say undercutting is what would concern me the most, same as tubes. Is anyone putting a tight cluster of LED's together to try to simulate a point source I wonder?

Steve

This one claims to have less undercutting than a metal halide:

http://lightspeedequipment.com/

Not sure if that's the case.

[blue moon]

as mentioned and tested, the undercutting was negligible. Most shops can't hold the dot small enough to even notice. (at least that was with the unit we tested). For somebody needing to hold a 3% dot, MH still seems to be the way.

Due to the design and the layout of the LED bulbs, I find it hard to believe it could be better than MH. I am often proved wrong, so it might be possible, I just don't see it happening. I should add though that Lou mentioned he managed to tweak it a little more and make it better than it was. So one never really knows. . .

pierre 

[ScreenFoo]

I'm really interested in the tech, but as I've theorized before (and will theorize again, I'm sure) the parts and engineering costs are just too high to make an affordable product right now that will be better than a MH unit.  If the costs keep dropping as they have been, it shouldn't be too incredibly long though.  I feel bad for jumping on Lou after his initial claims, but I get the feeling it won't be too long before someone could have a product that really measures up to those initial claims.

The other thing that hasn't shaken out yet is what happens when the first LED units have warranty issues.  A single LED going out is likely to significantly affect the capabilities of the unit.  We will see.

Great to hear there are some in the trenches already, sounds to me like a significant step up from fluo units for a reasonable cost.

[Doug S]

Been printing all day so I haven't had time to really keep up with the latest post. 

The led bulbs are approximiately 6 to 7 inches from the glass.  There are 8 evenly spaced light bars with 12 leds each.  One of the 230's I exposed yesterday had 6 point arial light text.  I noticed no loss of detail or loss of fine lines due to undercutting.  Keep in mind, that I don't have a tool to measure this.  I have yet to experiment with halftones but I will as soon as time permits.  I am going to perform exposure test to get the correct exposure times for the photopolymer I have "Chromaline Blue" and also water resistant which I should have next week "CCI WR-25".  I will post the results of both on the coating method I use which is 2/1 and mesh counts.  The nuarc 3140 I have produced some nice exposures but I have to admit, I don't think I'll miss the hot glass which causes the film, ink and the double-sided tape I use with my pre-registration to stick to the back of the screen.   

[Gilligan]

Didn't the mighty joe or whatever it was called have a single row that scanned like a scanner?  Maybe I dreamed that.

[Frog]

Looking at the diagram in Admiral's link, I can't help but wonder that, similarly to the half-assed double quartz set-ups I have seen,
wont the overlap areas receive more light?

[Gilligan]

IF planned right... then the fall off/inverse square law would just be canceled out by this "overlap".  IF planned right of course.

[ScreenPrinter123]

IF planned right... then the fall off/inverse square law would just be canceled out by this "overlap".  IF planned right of course.

I think this was one of flipper's considerations back in the 80's when he (or properly speaking "it") was designing his/its LED unit. I'll have to go check the episodic archives.  ;-)