screen printing > DIY - From master engineered marvels to cobbled together jury-rigged or Jerry-built junk!
My DIY LED "Expansion" Board
IntegrityShirts:
I don't think that chart is accurate given what abuffington has posted since this thread started.
I was originally trying to figure out which wavelength to buy but I think the quality of the Led is just as important.
blue moon:
--- Quote from: Gilligan on December 01, 2014, 06:40:23 PM ---
--- Quote from: blue moon on June 18, 2014, 08:42:53 AM ---from what I can tell, PhotoPolymer emulsions are really liking 340 or so for exposure, so chances are your times would be significantly lower with lower wavelength. See chart from Ulano below:
pierre
--- End quote ---
Am I reading this wrong or wouldn't the 350nm be just the perfect wavelength for everything? (if you had to pick just one) It hits SBQ at 87%, Fe+++(whatever that is) at 52% (not great but WAY better than 5% that the 405nm hits it at), Diazo at 93% and Diazo/AC (whatever that is) at 70% (again, better than 45% that the 405 hits it at).
If you had to pick ONE wavelength what would it be?
--- End quote ---
that chart is only half of the picture (go figure!). Turns out there is penetration and activation. First one has something to do with how well the light gets through and the other is what light activates the best. They are quite a bit apart and it seem the best spot (in between both) is in the 385 or so range for most emulsions. I'll see if I can dig up the other chart.
pierre
blue moon:
--- Quote from: blue moon on December 02, 2014, 10:10:20 AM ---
--- Quote from: Gilligan on December 01, 2014, 06:40:23 PM ---
--- Quote from: blue moon on June 18, 2014, 08:42:53 AM ---from what I can tell, PhotoPolymer emulsions are really liking 340 or so for exposure, so chances are your times would be significantly lower with lower wavelength. See chart from Ulano below:
pierre
--- End quote ---
Am I reading this wrong or wouldn't the 350nm be just the perfect wavelength for everything? (if you had to pick just one) It hits SBQ at 87%, Fe+++(whatever that is) at 52% (not great but WAY better than 5% that the 405nm hits it at), Diazo at 93% and Diazo/AC (whatever that is) at 70% (again, better than 45% that the 405 hits it at).
If you had to pick ONE wavelength what would it be?
--- End quote ---
that chart is only half of the picture (go figure!). Turns out there is penetration and activation. First one has something to do with how well the light gets through and the other is what light activates the best. They are quite a bit apart and it seem the best spot (in between both) is in the 385 or so range for most emulsions. I'll see if I can dig up the other chart.
pierre
--- End quote ---
OK, read this:
http://www.screenweb.com/content/tips-optimum-screen-exposure
IntegrityShirts:
Yeah I keep re-reading that article over and over again haha. Well, if anyone out there wants to try this project, I'd suggest going with a 385nm or lower LED strip to see how it compares to the 395nm strips North and I have already tested with similar results. I have a feeling the 10nm lower strips might be the ticket to a quicker complete exposure.
If I can source a non-shady supplier, I may give it another go here this month as it is the slow season now.
mimosatexas:
I know this has been discussed here and there, but I would love to start a comprehensive thread about these DIY LED builds with standard formatting and an updated first post with details of each build and some kind of consensus summary. After the new year I think I am going to try my own build and would like to further the development and discussion rather than rehash others mistakes and what not.
Can you detail the following in this format, and note after each what you might change or like to see tried for comparison:
LED Details:
-Source
-Cost (in total/per LED/shipping/etc)
-Wavelength (and any other details related to the light output itself)
-Electrical requirements/wiring diagrams, etc.
Build Details:
-Overall Size
-LED Layout (distance between bulbs,distance from glass, etc)
-Glass (thickness, type, source, etc)
-Peripheral info related to vacuum blanket, etc
Film/Emulsion/Exposure Details:
-Type of emulsion and coating technique
-Film brand and printer output
-Exposure Times and mesh used
Random thoughts, what you would improve, etc:
Navigation
[0] Message Index
[#] Next page
[*] Previous page
Go to full version