Author Topic: Vastex 2000 LED exposure unit teaser  (Read 19487 times)

Offline JBLUE

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Re: Vastex 2000 LED exposure unit teaser
« Reply #30 on: October 15, 2013, 11:39:46 AM »
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.

Can you expose some linearized 55 and 65 lpi screen halftone screens? I am waiting for someone to share that info....... :)

The exposure calculator has 65, 85 and 105 line halftones from 0-100%.  The LED held the same dot as the MH unit.  On the 65 line it held the 5% down to the 97% coverage hafltones, I didn't really look at the 85 and 105's because those dots are way too small for a 305 in my opinion.  I did hold them in probably the 9%-82% range on the 85 line row but I don't remember at all what the 105 looked like, I rarely pay much attention to that row because if my guy outputs anything at 105 I'm gonna put a boot in his rear.

If that exposure calc was image set thats good news. Most shops cant hold a true 5% dot anyways let alone print it. Thanks Alan.
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Offline alan802

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Re: Vastex 2000 LED exposure unit teaser
« Reply #31 on: October 15, 2013, 11:56:50 AM »
Yeah Blue, it's an imagesetter film.  The halftone dots are so clean and crisp compared to an inkjet.  The epson film with accurip makes a decent halftone that looks fine by eye but under a loupe you can really see the difference.  The hafltones I've seen from most inkjets look like little meatballs and the imagesetter dots are like ball bearings.  But that difference you see through a loupe means very little when printing on a t-shirt so anyone with an injet and a RIP can do some amazing things.
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Online tonypep

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Re: Vastex 2000 LED exposure unit teaser
« Reply #32 on: October 15, 2013, 12:32:06 PM »
Imagesetters were what we used at companies like OATS, Winterland, Harlequin etc in the days before inkjet and yes, in some cases print quality was actually better than today in some cases but not by enough to affect sales. Andy A is the only one I know of who still uses one but I'm sure there are others. And yes the dots are truly round and not popcorn (or meatball!)

Offline blue moon

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Re: Vastex 2000 LED exposure unit teaser
« Reply #33 on: October 15, 2013, 01:02:44 PM »
Imagesetters were what we used at companies like OATS, Winterland, Harlequin etc in the days before inkjet and yes, in some cases print quality was actually better than today in some cases but not by enough to affect sales. Andy A is the only one I know of who still uses one but I'm sure there are others. And yes the dots are truly round and not popcorn (or meatball!)

I think Andy's bailing wire finally gave up and he is using an EPSON now. . . .

pierre
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Online tonypep

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Re: Vastex 2000 LED exposure unit teaser
« Reply #34 on: October 15, 2013, 01:11:58 PM »
HA! Not surprised last time I was there he was pretty worried about parts

Offline JBLUE

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Re: Vastex 2000 LED exposure unit teaser
« Reply #35 on: October 15, 2013, 01:25:44 PM »
Excellent. One of your boys is stopping by tomorrow, I'll be sure to request some pricing.
Pricing and information to the regional wont be ready until the day before the show. Still pricing the BOM.

Can you throw one in the crate with my new dryer? My old 3140 has seen better days......lol
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Offline Homer

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Re: Vastex 2000 LED exposure unit teaser
« Reply #36 on: October 16, 2013, 06:04:53 PM »
not sure if it's been posted or not, but did you guys see this one?

http://lightspeedequipment.com/patent-pending-led-uv-exposure-unit/
...keep doing what you're doing, you'll only get what you've got...

Offline Gilligan

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Re: Vastex 2000 LED exposure unit teaser
« Reply #37 on: October 16, 2013, 06:14:38 PM »
I don't know about that "pattern" of bulbs... doesn't seem uniform.

http://lightspeedequipment.com/wp-content/uploads/patent-pending-led-uv-exposure-300x128.png


I like his demo area, good place for UV exposure "test". :)


Offline ScreenPrinter123

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Re: Vastex 2000 LED exposure unit teaser
« Reply #39 on: October 18, 2013, 01:45:00 PM »
So M&R's new exposure unit only works with those who have a CTS???????  Ouch... 

"Since D-Scan is designed to work in conjunction with screens that have been imaged on CTS systems and since it does not utilize vacuum or glass, will not work properly with conventional film positives."

Offline Orion

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Re: Vastex 2000 LED exposure unit teaser
« Reply #40 on: October 18, 2013, 01:59:46 PM »
 We use CTS. Surely they have developed a unit for conventional film exposures.
Dale Hoyal

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Re: Vastex 2000 LED exposure unit teaser
« Reply #41 on: October 18, 2013, 02:04:49 PM »
I just realized that the absence of glass could be one of the contributing factors of shorter exposure times.

Does anyone have real numbers on this factor? How much does the glass filter out?
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Offline Admiral

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Re: Vastex 2000 LED exposure unit teaser
« Reply #42 on: October 18, 2013, 02:09:41 PM »
Not using glass makes our exposure times 40% faster.  Sometimes it's more like 50-60% on the low mesh screens.

I have real numbers if you really care I can get later.

I like the fact that it is space saving but it looks expensive and an LED / no glass / no vacuum exposure unit that is just a LED on off timer should be very inexpensive imo compared to a 5-10k watt MH unit.

Offline Orion

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Re: Vastex 2000 LED exposure unit teaser
« Reply #43 on: October 18, 2013, 02:10:40 PM »
In our case, exposure time was reduced 60-70 percent.
Dale Hoyal

Offline ZooCity

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Re: Vastex 2000 LED exposure unit teaser
« Reply #44 on: October 18, 2013, 02:22:13 PM »
So why is that M&R not just one unit- CTS followed by LED scan?  That would be slick.