DIY LED Exposure Unit - The Saati Screen Toaster

[zanegun08]

Wanted to share our DIY exposure unit.

We got tired of waiting for the perfect solution to come along, the starlight worked great in testing, but loading is cumbersome for CTS, the Gemini is huge and expensive, but is better ergonomically for CTS, the Lightspeed that Exile sells looks great, but there are less LED's than starlight, and worried about undercutting.

So, we got restless, and wanted to give my screen operator something to do while the printer is printing, so rather than having another person expose in the 5K MH, he can now do both, and now it keeps our 5K free for post expose, or jumbo screens, and the screen room stays cooler overall.

"The Saati Screen Toaster" takes the same Saati single point LED light, which they sell as standalone.  This is the same light in the table unit sold by both Saati and Ryonet, it just comes with a different controller which isn't as cool as the gimmicky bluetooth android app, but functions just as well, and no bluetooth connectivity issues or anything to be concerned about, or charging a tablet, ect.

We just built a "Toaster" to contain the screens, they slide in against some plastic, sit it in, put in seconds based on screen mesh, hit expose.  After they are exposed we stack them on top and then the guy who previously grabbed them to put to light, now grabs them and puts in a dip tank of water, then sprays out.

Basically it keeps a better constant flow, screens get equal results, and is faster than the printer so we can keep a constant waterwheel of screens going throughout the day.  We average around 150-200 screens a day.



Sits next to the Spyder for easy workflow, although I think this could be better by putting them at a right angle, but like to keep spaces open.



Close up of this state of the art equipment 



Magic in action 

There is some light leakage, but I don't think it is enough to effect any of the screen in storage nearby.  Overall it works pretty well, cost around ~2300 all in, that is why we couldn't justify paying another 2 grand for a box that we didn't even love how it functioned for our workflow.

Our exposure times range from around 10 seconds on a 305 to 30 seconds on a 110, and 50 on an 83.  The goal wasn't to be race car fast, just be faster than the Spyder II which based on our average work takes around 45 seconds to print a screen, not including loading / unloading, so the light can beat the average workflow of the Spyder II

Let me know if you have any ideas for improvements?  Or if you have any questions. 

[bulldog]

Very cool.

[screenprintguy]

What if you put two of those led clusters in there, think it would give a stronger faster cook? Just curious.

[zanegun08]

What if you put two of those led clusters in there, think it would give a stronger faster cook? Just curious.

If I were to put two in, then my cost would be the same as a starlight, so I would just buy that.  As long as my average speed is faster than my Spyder II output of ~45 seconds, then I'm happy.

The size of the light is large, and the point is to have one in the center of the screen so you don't have undercutting from multiple light sources.  Getting a 3 second exposure is not the goal as I think people exposing for that amount of time are either under exposing for our preference, or embellishing numbers.

One piece I left out, we use Kiwo MultiTEX emulsion (Pure Photopolymer), coated 1/2 sharp side on an auto coater.  We print with everything from Solvents to HSA on this single emulsion.  I think if we were still using an emulsion with diazo this may not work (fast enough) and we wouldn't have kept the light, as we can expose 6 up on our 5k.

[Wildcard]

Is this using the Saati 300w led lamp? What did that cost btw? Any chance of seeing a photo of the lamp inside the box?

[zanegun08]

Here is a shot of the inside.  I believe it is a different light than what you are talking about. 

It is the same light that is in the Saati and the Ryonet FX Eposure unit, Saati makes the light, Ryonet builds the box / android app.

The light and controller pictured above I believe came in at just under 2k.  So the total cost was probably less than $2300, but I like to over estimate.  Check with Saati on pricing though as I could be wrong, I don't sign the checks.



Basically it is just built up so that the center of the light is even with the center of the screen, and around 25-30" from the screen to the light.  It looks like the glass comes off the front easily which may decrease exposure time, but we are already faster than we need to be, so it isn't of great concern and I'd rather keep the light clean from dust.

Lastly, to improve we probably could've painted the inside of the box black with a paint to absorb light, as there is likely some reflecting off the sides, top, bottom, back, but it doesn't seem to be effecting anything, and my screen guy said he is getting easier wash out of the image than with our 5k.

Pretty low tech, but well functioning.  My biggest complaint is the controller only has up and down arrows for setting seconds, minutes, or hours, it'd be nice to have a keypad to just key in seconds, but changing between around 15-30 seconds isn't a huge deal.  Just if you are listening Saati, if you have a better controller, send it over

[Maff]

This is really awesome!
I'm very interested in the Saati/Ryonet unit, but I'm on film positives so i need the vacuum. 
Are you post exposing screens for WB/DC? Have you tried any other PP emulsions on it?

[Prōdigium]

A very interesting thread and project, still a bit on the pricey side though.

I live in the heart of LED production in China, after reading this thread I decided to do some checking around and I am shocked at how cheap these LED's are....I can get a box of 500 for $125 Each bulb is 5watt, puts out 395nm wavelength. Makes me wonder how companies are getting off charging $5000 for these things.

[Admiral]

A very interesting thread and project, still a bit on the pricey side though.

I live in the heart of LED production in China, after reading this thread I decided to do some checking around and I am shocked at how cheap these LED's are....I can get a box of 500 for $125 Each bulb is 5watt, puts out 395nm wavelength. Makes me wonder how companies are getting off charging $5000 for these things.

To cover R&D.  Prices will drop over the next 5-10 years and they will likely become the norm.  There still are a lot of MH purists though, but the technology of LED will improve as well.

[mk162]

I had a friend working at GM, the average cost to assemble an $18k vehicle was less than $3k.  And they were rolling those off the line much faster than LED light units.

We get that you can buy the bulbs cheap...hell a MH bulb isn't that pricey either, but you need to look into everything else that comes with the unit.

No offense, please give it a rest on the cost of the LED.

[firefighter17]

Here is a shot of the inside.  I believe it is a different light than what you are talking about. 

It is the same light that is in the Saati and the Ryonet FX Eposure unit, Saati makes the light, Ryonet builds the box / android app.

The light and controller pictured above I believe came in at just under 2k.  So the total cost was probably less than $2300, but I like to over estimate.  Check with Saati on pricing though as I could be wrong, I don't sign the checks.



Basically it is just built up so that the center of the light is even with the center of the screen, and around 25-30" from the screen to the light.  It looks like the glass comes off the front easily which may decrease exposure time, but we are already faster than we need to be, so it isn't of great concern and I'd rather keep the light clean from dust.

Lastly, to improve we probably could've painted the inside of the box black with a paint to absorb light, as there is likely some reflecting off the sides, top, bottom, back, but it doesn't seem to be effecting anything, and my screen guy said he is getting easier wash out of the image than with our 5k.

Pretty low tech, but well functioning.  My biggest complaint is the controller only has up and down arrows for setting seconds, minutes, or hours, it'd be nice to have a keypad to just key in seconds, but changing between around 15-30 seconds isn't a huge deal.  Just if you are listening Saati, if you have a better controller, send it over

I know this is an old thread but thought I would still ask.... where did you purchase the bulb from, directly from Saati or another distributor? Thanks!

[Frog]

I know this is an old thread but thought I would still ask.... where did you purchase the bulb from, directly from Saati or another distributor? Thanks!

Now you have to hope that the OP clicked the option to be notified of responses to his thread in his profile.

[Sbrem]

I'm pretty sure, not completely, that you can get it from Saati directly. Call them, the worst they'll say is no, right?

Steve

[Colin]

Zane is in Portland.  My guess is he got it from Ryonet, since they are across the river from him.

[zanegun08]

Got it from Saati direct.  Still in use everyday with no problems.

Saati makes the light, Ryonet makes the box / controller.  When buying from Saati direct you get a low tech controller, no frills but it works well.  The only issue is you have to key up and down 1 press for 1 second, and while some meshes are 40 second exposures, the next could be a 10, so you have to hit the button 30 times which is annoying, but it is what it is.  Could probably get a fancier controller as all it really is, is 110 plugin timer, could be a good arduino project or something to program a little controller with preset buttons.



We built it for 23" x 31" frames only, it doesn't even need a box, just contains the UV as we have unexposed screens right by it, as well as are imaging while the next screen is printing.

I believe the light was between 2k - 2.5k when we bought it.  Maybe it's come down in price in that time?

I know Exile is working on one that they will sell, but probably more inline with the Starlight which when we were testing even without glass took longer to expose than the light setup we have.  As well as ours is more ergonomic, and faster to load and unload screens in it.

Low Tech