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screen printing => Equipment => DIY - From master engineered marvels to cobbled together jury-rigged or Jerry-built junk! => Topic started by: zanegun08 on March 04, 2016, 07:32:26 PM
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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.
(http://s10.postimg.org/h5ug652bd/IMG_6325.jpg)
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.
(http://s10.postimg.org/3q7fgottl/IMG_6324.jpg)
Close up of this state of the art equipment ;)
(http://s10.postimg.org/j07anvpbt/IMG_6326.jpg)
Magic in action 8)
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.
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Very cool.
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What if you put two of those led clusters in there, think it would give a stronger faster cook? Just curious.
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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.
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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?
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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.
(http://s24.postimg.org/d61wqnrit/IMG_6328.jpg)
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
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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?
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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.
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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.
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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.
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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.
([url]http://s24.postimg.org/d61wqnrit/IMG_6328.jpg[/url])
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!
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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.
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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
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Zane is in Portland. My guess is he got it from Ryonet, since they are across the river from him.
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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.
(http://s10.postimg.org/3q7fgottl/IMG_6324.jpg)
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
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That's a great exposure unit, all you need for CTS.
I am using the Saati 300W and Saati PHU, very happy with the results, I use film so still need a vacuum.
A suggestion, make a little flap that you can hinge onto the top and flip over when you put the screen in.
It would stop the light leaking out, possibly the UV is also not good for the person working there. (Not sure about that).
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A suggestion, make a little flap that you can hinge onto the top and flip over when you put the screen in.
It would stop the light leaking out, possibly the UV is also not good for the person working there. (Not sure about that).
We have thought about that, but the light that comes out the top and through the screens seems to be pretty weak, and a flap would just be something you have to move in and out of the way.
(http://s10.postimg.org/j07anvpbt/IMG_6326.jpg)
I don't think the leak affects the the screens around it, especially since they are mostly stored tightly together so the frames block most of the light.
Did you set yours up in an already existing box, I see you posted about having glass, you use films still?
I tested the starlight multiple times, and looked at the gemini (way to expensive) and other exposure units, Saati let us try before we bought the light, and it worked great. We still have a 5k MH for oversize screens, smaller screens, post exposure, but this does the trick for 90% of our screens and keeps up with the Spyder, so it's a constant flow of screens.
I'm not a light scientist, but the single point light may work better than the multi strip LED units in regards to undercutting, and halftones as well, but we aren't really trying to produce 85lpi prints, we still need to work on printing white ink on black :-\ but I'd say for 95% of screen printers this would be a major upgrade and ideal setup with CTS / LED Exposure, and cost about 20k less than I-Image STEII with the same end result (if not better for halftones with wax)
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I still have glass and vacuum. Love to get a wax printer but have invested heavily in moving my plant, a new printer and oven. Need to pay for these before I invest more and the wax printers are not cheap.
I have always used home made exposure units and I cannot think of anything commercial that would work better than what you built. The most important thing is the light source and yours is great.
As for undercutting for years the theory was that you need a spot light source, now we are being told that strips of LED are OK.
I do not think there will be much if any undercutting with CTS no matter what light source you use, you could use the sun if you kept the back of the screen in the dark.
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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.
([url]http://s10.postimg.org/3q7fgottl/IMG_6324.jpg[/url])
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
Thank you for the info, I will contact Saati!
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I've been trying to find this at the Saati site, but no luck... I guess a call is in order...
Steve
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I've been trying to find this at the Saati site, but no luck... I guess a call is in order...
Here is the brochure, I got it through Grant Hewitt at Saati who is now retired but still around, so he may be able to help.
I don't see it on their website either.
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wait... Grant ACTUALLY retired....?
That man cant retire, it's not in his genome....
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wait... Grant ACTUALLY retired....?
That man cant retire, it's not in his genome....
Like I said, "retired but still around" which mean's he didn't actually retire, but officially retired unofficially.