Author Topic: Olec boom... time for LED?  (Read 743 times)

Offline Atownsend

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Olec boom... time for LED?
« on: May 02, 2022, 02:23:36 PM »
Loud boom in the exposure room today. Bad smells... popped the cover on the power supply. One of the contactors on the capacitor was trying to light itself on fire when the unit was in operation. Posts on top burnt to a crisp. I noticed that one of the resistors on one of the other caps was also desoldered....fun thinking that could be the origin of the issue, but who knows. Called Mark up @ douthitt, they're overnighting me some new capacitors. Kudos to Douthitt for hooking it up. Hopefully I can get this rolling tomorrow since sun exposure is not something I really want to do any more of.

Thinking about the future here... anyone use the Saati single point LED? I'm reading that it doesn't need an integrator, but im wondering how you'd interface a timer with it. If you're using it, how do you like it? Getting good exposures? What is the expo time / distance? Can we run two up?

We run photopolymer and plastisol so I dont think we'd run into some of the issues that a waterbased printer would... but I still want the best resolution from our light, so multipoint light sources are out for that reason.





Offline ericheartsu

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Re: Olec boom... time for LED?
« Reply #1 on: May 02, 2022, 02:31:34 PM »
we have both units here, but primarily use the Saati 3kw toaster. It comes with a timer.

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Offline Sbrem

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Re: Olec boom... time for LED?
« Reply #2 on: May 02, 2022, 05:18:14 PM »
We have the Pro-Lite 450, works great. Yes we had to do some testing to get the exposure times down for Ulano Orange and Saati HU-42. We probably have it slightly closer to the vacuum frame than our old Violux 5000S, and yes, you should be able to do 2 up manual size, we do 2 up on 23 x 31 as well.

Steve
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Offline blue moon

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Re: Olec boom... time for LED?
« Reply #3 on: May 03, 2022, 09:02:44 PM »
it has a really pronounced hot spot in the center. You'll have to have it pretty far away to get good light distribution. I think we have it almost 4 feet away.
Single wavelength at 405nm. I would prefer multi spectrum, but at this point the convenience trumps most other potential issues.

pierre
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Offline Atownsend

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Re: Olec boom... time for LED?
« Reply #4 on: May 03, 2022, 09:16:11 PM »
Thanks y’all! I was able to rewire our caps today pretty easily & got the Olec back into production. Mark seems to be able to help us fix just about anything with a 5 min phone call and next day air.

I really like the idea of the LED. But theres something about those transformers buzzing in and the caps charging that is just screams total badassery. The Saati units seem to be stocked well, so I spoze I’ll keep the Olec around until something majorly catastrophic happens and I need to overnight one of those haha.

Offline Atownsend

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Re: Olec boom... time for LED?
« Reply #5 on: May 03, 2022, 09:19:01 PM »
it has a really pronounced hot spot in the center. You'll have to have it pretty far away to get good light distribution. I think we have it almost 4 feet away.
Single wavelength at 405nm. I would prefer multi spectrum, but at this point the convenience trumps most other potential issues.

pierre

Multi spectrum would be very tight. The thing that kind of throws me off a bit is the lack of an integrator. Do the LEDs really never age? I’d think that the output has to diminish over time right?

Offline Sbrem

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Re: Olec boom... time for LED?
« Reply #6 on: May 04, 2022, 11:54:46 AM »
I've never used an integrator. With the older MH Bulbs, we could see when they were losing their "oomph" and screens would start to seem a little underexposed. Yes, that's not very scientific, but we've made a few hundred thousand screens this way. The LED has been very consistent. As I said, we're 2 years in with it. Heck, I started with NuArc Carbon Arc lamp. They were like a miniature sun, fantastic light source, except for the poison smoke. We're totally happy with the Pro-Lite 450.

Steve
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Offline ZooCity

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Re: Olec boom... time for LED?
« Reply #7 on: May 05, 2022, 11:20:22 AM »
*Shameless yardsale hustling- We have a pair of good, complete Olec units and integrator if you are interested in a good deal on them.  Can crate and arrange shipping.  FOB 59801

Due to amperage limitations we went LED with a Starlight years ago. Light is provided by rolls of off the shelf (non-proprietary), narrow spectrum LED strips glued to a board.  The board is overspanned/undersupported and droops in the middle so the light pattern is not collimated.  There's no integrator.  Ventilation is not adequate for longer exposures- the heat will warp the glass.  There's no filtration on the ventilation that's there so dust gets in.  It basically goes against all the science I know (or thought I knew?) regarding proper exposure, lol.

Despite all this, the unit performs just fine and we experienced no effective difference in quality from MH.  I still prefer MH but I can't argue with the effectiveness of the Starlight.   Think analog to digital music- analog is better but digital gets it done well enough.

You have to adjust emulsion type and EOM to accommodate but that turned out to be a good thing for us.   LED screens may need hardener where MH do not but you can integrate that into the resolve process if yer clever.

All LEDs experience lumen degradation (I think there's a rating for this that tells you how many hours until the drop in output) but the typical number of hours it takes for a quality LED to drop in output make this a non-issue in our context.  I do maintain that all expo units should have an integrator unless they have circuitry designed to deliver very consistent voltage to the LEDs.