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Discussion Starter · #1 ·
Here's my $100 DIY LED exposing unit build and only required basic electrical and soldering skills...
I had an old National vacuum exposing unit with single quartz bulb and two fluorescent black light bulbs. I removed the single quartz bulb and replaced it with a 100w 395nm UV LED chip I purchased on Amazon. The Amazon purchase also included a heat sink w/fan and an LED Driver. Here's the links...

LED Chip
https://www.amazon.com/gp/product/B01DBZI4SA/ref=oh_aui_detailpage_o06_s00?ie=UTF8&psc=1

LED Driver
https://www.amazon.com/gp/product/B01NBXZUS3/ref=oh_aui_detailpage_o06_s00?ie=UTF8&psc=1

Heatsink
https://www.amazon.com/gp/product/B01D1LD68C/ref=oh_aui_detailpage_o06_s00?ie=UTF8&psc=1

I plugged it into an extention cord and it lit up! So in the next day or two I plan to wire it into the timer on the exposing unit. Hopefully this will shave some time off exposures from the old school quartz bulbs. Let me know if you have any comments or suggestions!
 

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I purchased a LED tablet on Amazon for only $75.00 that is a 11 x17". This tablet is the thickness of a plate glass. It is also adjustable for light.
I use it for registering to sheets of IC for Dark paper to press them together.
AL
1-908-213-2830
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Discussion Starter · #4 ·
We've been using the new DIY LED system for a week now and it seems to work good. However, the exposure time didn't drop as much as I would have liked. The previous buld was quartz and our exposure times were 10-12 minutes. The exposure time now is 5-6 minutes with the new LED chip. We're using KIWO PolyPlusS for emuslion. I might experment with testing different emulsions to see if we can get our exposure time even lower. For now we're happy to have the 50% decrease in exposure times.
 

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Here's my $100 DIY LED exposing unit build and only required basic electrical and soldering skills...
I had an old National vacuum exposing unit with single quartz bulb and two fluorescent black light bulbs. I removed the single quartz bulb and replaced it with a 100w 395nm UV LED chip I purchased on Amazon. The Amazon purchase also included a heat sink w/fan and an LED Driver. Here's the links...

LED Chip
https://www.amazon.com/gp/product/B01DBZI4SA/ref=oh_aui_detailpage_o06_s00?ie=UTF8&psc=1

LED Driver
https://www.amazon.com/gp/product/B01NBXZUS3/ref=oh_aui_detailpage_o06_s00?ie=UTF8&psc=1

Heatsink
https://www.amazon.com/gp/product/B01D1LD68C/ref=oh_aui_detailpage_o06_s00?ie=UTF8&psc=1

I plugged it into an extention cord and it lit up! So in the next day or two I plan to wire it into the timer on the exposing unit. Hopefully this will shave some time off exposures from the old school quartz bulbs. Let me know if you have any comments or suggestions!
Hi, great work! I think I might follow your same method and attempt to build an exposure unit myself.
Can I ask you, did you keep the two fluorescent black light bulbs in the unit or have you removed them?

Thanks very much
 

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Here's my $100 DIY LED exposing unit build and only required basic electrical and soldering skills...
I had an old National vacuum exposing unit with single quartz bulb and two fluorescent black light bulbs. I removed the single quartz bulb and replaced it with a 100w 395nm UV LED chip I purchased on Amazon. The Amazon purchase also included a heat sink w/fan and an LED Driver. Here's the links...

LED Chip
https://www.amazon.com/gp/product/B01DBZI4SA/ref=oh_aui_detailpage_o06_s00?ie=UTF8&psc=1

LED Driver
https://www.amazon.com/gp/product/B01NBXZUS3/ref=oh_aui_detailpage_o06_s00?ie=UTF8&psc=1

Heatsink
https://www.amazon.com/gp/product/B01D1LD68C/ref=oh_aui_detailpage_o06_s00?ie=UTF8&psc=1

I plugged it into an extention cord and it lit up! So in the next day or two I plan to wire it into the timer on the exposing unit. Hopefully this will shave some time off exposures from the old school quartz bulbs. Let me know if you have any comments or suggestions!

I'm curious to know, if you added more of the lights (say 6+) would that be doing to much?
 

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Discussion Starter · #8 ·
Hi, great work! I think I might follow your same method and attempt to build an exposure unit myself.
Can I ask you, did you keep the two fluorescent black light bulbs in the unit or have you removed them?

Thanks very much
Sorry for delay in replying... I kept them in for good measure. However, I took them out to test exposure times without them and I didnt see any increase or decrease in time or exposure quality.
 

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We've been using the new DIY LED system for a week now and it seems to work good. However, the exposure time didn't drop as much as I would have liked. The previous buld was quartz and our exposure times were 10-12 minutes. The exposure time now is 5-6 minutes with the new LED chip. We're using KIWO PolyPlusS for emuslion. I might experment with testing different emulsions to see if we can get our exposure time even lower. For now we're happy to have the 50% decrease in exposure times.
Take the lens off. It blocks a lot of the usable UV Build a reflector to help contain the light try 8"x10" tapered down to the LED. Then move up the LED so that it exposes the screen plus 1/2" when doing this after the lens is removed on should wear good sunglasses while making adjustments and looking at the light. It can damage your eyes.

Is that LED mounted on the bottom. I used the National to make a metal Halide and then to a LED. There should be pics on the site here. My light 200w LED about 15" I think. Same distance when I used the 100w with same reflector I used foil HVAC board available at most big box hardware store.

My current 200w setup with Saati Chem PHU 8-12 sec with the 100W 20-30 sec.

Didn't look up you emulsion but guessing its diazo. with 100w lens removed, reflector, and adjusted I'm guessing 45sec-1:30 but more importantly cooking the screen fully
 

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Discussion Starter · #10 ·
Take the lens off. It blocks a lot of the usable UV Build a reflector to help contain the light try 8"x10" tapered down to the LED. Then move up the LED so that it exposes the screen plus 1/2" when doing this after the lens is removed on should wear good sunglasses while making adjustments and looking at the light. It can damage your eyes.

Is that LED mounted on the bottom. I used the National to make a metal Halide and then to a LED. There should be pics on the site here. My light 200w LED about 15" I think. Same distance when I used the 100w with same reflector I used foil HVAC board available at most big box hardware store.

My current 200w setup with Saati Chem PHU 8-12 sec with the 100W 20-30 sec.

Didn't look up you emulsion but guessing its diazo. with 100w lens removed, reflector, and adjusted I'm guessing 45sec-1:30 but more importantly cooking the screen fully

Thanks for the info! We have the lens off but left the little cone reflector on that came with the LED. Good idea with furnace foiled cardboard, I'll give that a try. I experimented with moving the LED closer to the screen but found resting the LED on floor of old exposing unit worked best for our larger 23x31 auto screen. I should order a sample of the Saati emulsion, we're using KIWO POLYPLUS-S and the exposure times have been disappointing with this LED setup.
 

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Firefighter, did you get any better results? Did you switch to a 200 watt LED.
IM trying to convert same old exposure to LED right now. I have a 100 watt but reading results and advice from Sben am debating 200 watt.
Sben said 20-30 sec exposure time with 100 watt, that seems great to me but you are getting 5-7 mins.
 

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Firefighter, did you get any better results? Did you switch to a 200 watt LED.
IM trying to convert same old exposure to LED right now. I have a 100 watt but reading results and advice from Sben am debating 200 watt.
Sben said 20-30 sec exposure time with 100 watt, that seems great to me but you are getting 5-7 mins.
The problem with comparing wattage is not all UV LED are created equally. firefighters bulb may state 395-405nm but what I found with some bulbs is they just color the coating and use cheaper LEDs thus firefighters bulb may only be equivalent to 25-50 watts of a 100w that puts off the correct wavelength. That brings up your emulsion. Every manufacture has a peak wavelength for their emulsions. some are low as 356nm all the way up to 405nm. Saati Chem says 405nm but with my bulbs I got a little better detail and full crosslinking at 395nm but 12 sec exposures. I am still running the 405nm 200w in the original unit. I built and sold 8 units with the 385-395nm. Another thing that can really extend exposure time is the glass. After using the stock National, a low iron replacement and the starphire by PPG(it has a new brand name Vitro) the Starphire is far superior


A reflector has to be built to contain the UV and focus the beam. I made mine out of reflective cardboard sold in big box stores for duct work. I made 3 versions after testing each. the one that worked best starts out the size of the outer die of LED and went up to about 10"x14". This and mounting the bulb about 12"-14", never measured. I put the 23x28 Neman rollers on the glass taped off around screen. I had side off mine so I could look under side of glass with light on ( and polarized sunglasses) and moved up and down till the beam was approximately at least 1 " over lapping the tape. I Used duct tape to hold reflector and heat sink assembly for temporary testing.... still have never mounted.
 
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Discussion Starter · #14 ·
shawnkspringhill, I suspect the LED chip I purchased on Amazon is not as advertised, 100w. The post below yours from sben763 describes it better. I’ve inspected he LED chip from Amazon and it does not have colored film or a glass lens on on it so not sure why my times are so far off from his other than it must be lower wattage than the advertised 100w.
 

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Discussion Starter · #15 ·
The problem with comparing wattage is not all UV LED are created equally. firefighters bulb may state 395-405nm but what I found with some bulbs is they just color the coating and use cheaper LEDs thus firefighters bulb may only be equivalent to 25-50 watts of a 100w that puts off the correct wavelength. That brings up your emulsion. Every manufacture has a peak wavelength for their emulsions. some are low as 356nm all the way up to 405nm. Saati Chem says 405nm but with my bulbs I got a little better detail and full crosslinking at 395nm but 12 sec exposures. I am still running the 405nm 200w in the original unit. I built and sold 8 units with the 385-395nm. Another thing that can really extend exposure time is the glass. After using the stock National, a low iron replacement and the starphire by PPG(it has a new brand name Vitro) the Starphire is far superior

A reflector has to be built to contain the UV and focus the beam. I made mine out of reflective cardboard sold in big box stores for duct work. I made 3 versions after testing each. the one that worked best starts out the size of the outer die of LED and went up to about 10"x14". This and mounting the bulb about 12"-14", never measured. I put the 23x28 Neman rollers on the glass taped off around screen. I had side off mine so I could look under side of glass with light on ( and polarized sunglasses) and moved up and down till the beam was approximately at least 1 " over lapping the tape. I Used duct tape to hold reflector and heat sink assembly for temporary testing.... still have never mounted.


sben, I changed emulsions, built a reflector even moved my LED chip around but am unable to achieve a faster exposure time. I suspect the LED chip I purchased on Amazon is not as advertised, 100w. Where is a good source for a good LED chip? Most of the places I found online want you to buy large quantities and I'm afraid eBay will be as unreliable as Amazon.
 

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I found sellers on Ebay sell 200 watt 395nm UV for $75ish. The high end was $130 but he may have a 200 watt for real. If it isnt 200 watt send it back. One seller sells the lens, 200 watt chip and LED driver for $138.

I bought what you had linked firefighter. I havent tested exposure but i did power the light and it didnt seem that bright. My flashlight LED is brighter and only cost $14.
 

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I've been doing a lot of research on LED's and really wanted to start using them but the more research I did about dodgy ebay sellers after reading this thread I am now no longer going to do it unless a reputable seller surfaces,
Here is a link I found interesting from a staunch guy who knows his stuff.

https://www.youtube.com/watch?v=NjKgPLeJ79Q

I know people just say send them back if they don't work properly but when they are coming from China and take upwards of a month to arrive and after watching this guy on youtube having a hard time himself finding a relliabe source, you have to wander if going down the strip build is more reliable even though it's an inferior way of exposing compared to single point.
 

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I see pricing on a 200 watt 395nm from $75 to $220.
What did you pay for the chips and call out the seller, we can weed them out over the next 20 years to find a reliable source. I bought a 100 watt chip from Amazon, how would i test the volts?
I got the LED driver from same seller and reviews said the driver was weak was the problem. One review got 2 of them one measured 2.2 volt the other 48volt.

Im losing interest in the LED upgrade on my Atlas and theres an Amergraph Advantage 150 on CL for $1,000.
 

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I found sellers on Ebay sell 200 watt 395nm UV for $75ish. The high end was $130 but he may have a 200 watt for real. If it isnt 200 watt send it back. One seller sells the lens, 200 watt chip and LED driver for $138.

I bought what you had linked firefighter. I havent tested exposure but i did power the light and it didnt seem that bright. My flashlight LED is brighter and only cost $14.
Brightness with the UV LEDs isn't a indication of its wattage. The brighter the more I can definitely say they are fake UV. The light you seek for exposure isn't visible. Visible light starts at about 400nm. Also very dull lights can also be fake due to the coating over the conductor to make the color. Most UV LEDs will appear to be about 1/2-1/3 of the actual wattage


The cheaper UV LED are definitely not worth messing with. https://www.t-shirtforums.com/screen-printing-equipment/t445018-2.html because of this thread and @Preston post and he claims a 20w and 50sec exposure and I say BS all the way. I have bought that exact light, the 100w listed here all from amazon and the 20w was over 13 min exposure. the 100w was over3 min. The 100w in a few of my videos exposed at 20-30 sec. This was the first bulb to give me quick, quality exposures. I then ordered a 200w from the same supplier/manufacture with a few modifications. and the bulb I still run 3 years later.


Don't ever use a lens, it either plastic or glass and in any case they are sold to make a beam, and more importantly protect viewing eyes. since your wanting the dangerous UV you don't want to block it. One could be used if it was thin and made out of low iron glass.


I am sorry to be vague on info but I do have to be careful here. When the project sold there were some stipulations and that's why some of my post and pictures were removed here. I am now allowed to sell units but it takes too much time for the return. I did for awhile sell bulb, heat sink, and driver kits for $300 but after a member here tried to do the paypal charge back (I won) and get theirs for free I lost all interest on dealing with that crap. I am a printer at heart. I started printing after a heart attack @35 in 2006 for stress relief so the extra hassle even making decent money isn't worth it to me.


All the junk bulbs shown in the video above are the cheapest crap there is, there are many good SELLERS on ebay and for the UV LED most are from china so yes can be a crap shoot to pick a good one. As a mechanical mechanic for 25+ years including a licensed electrician, plumber, HVAC and appliance tech, I have bought in the last 10 years over $150,000 or more in LED retrofit and replacement lighting from ebay sellers and 95% or better where exactly what was advertised. The stuff that seems to cheap to be true probably isn't. Most the time I say look at the feed back rating but in this case most UV in the range is purchased for "stoner bulbs" to make shirts and posters glow. It really doesn't take much for that to happen and so even inferior bulbs work.
 

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I see pricing on a 200 watt 395nm from $75 to $220.
What did you pay for the chips and call out the seller, we can weed them out over the next 20 years to find a reliable source. I bought a 100 watt chip from Amazon, how would i test the volts?
I got the LED driver from same seller and reviews said the driver was weak was the problem. One review got 2 of them one measured 2.2 volt the other 48volt.

Im losing interest in the LED upgrade on my Atlas and theres an Amergraph Advantage 150 on CL for $1,000.
Volt meter to test. on the DC SIDE ONLY. Has to be done properly. first test without light and get DC voltage. should be higher then the max range so if 48 is the top range you could see as high as 58-60v but with the light on depending on your wattage it should be closer to the range with the load on. Unless its a regulated driver which some may claim but you not getting a proper regulated driver for under $100 nor do you need one though.


Only issue with giving away seller is that's the company I had make my version of the 385-395nm 100w, 200w, 300w and sold. if they were to sell you my version that I sold, I could be sued. I can though buy and resell without recourse but selling bulb kits maybe making $100 minus shipping and then someone trying to screw you because they don't know how to make a proper screen isn't worth the time to me.


The single point metal halide units are great but also can be trouble. The more you strike the bulb the quicker it goes out,(expensive replacements) some as high as $500. I think the amerigraph strikes the bulb every time its used where as the M&R and may other you turn on and warm up before exposure. If your shop is hot then heat can be a issue with these as they put out a great amount of heat and most emulsions can be temperamental with heat. A great thing about these is if you make thick stencils as I do for special projects and effects they cook(expose) the screen thoughly. My 200w does well up to 75-100 micron stencils. Ive done up to 400 micron and why I had a 300w version made. it took 1 min with 200w and the same with 300w. The 200w was slightly tacky of back side but if let go any longer started to skin and difficult to remove of film side. The 300w was solid and this still puzzles me as I thought the 300w would drop the time on thicker stencils as well as cook the screen though. on standard thickness screens the 300w was less then 5 sec. but there was loss of detail on the thinner stencils.
 
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