I installed a total of 12 bulbs instead of @AtlasBrace’s 8 bulbs for a total of 108 watts of UV light. I substituted the reflective vinyl for a chopped up mylar emergency blanket and used wood glue to apply the mylar (before assembly). Also, instead of printing the light sockets, I found that the sockets from two of these UV nail dryers were easily removed and repurposed (nice they came with spare bulbs too). I had a different UV nail dryer that didn’t have removable sockets, but it was easy enough to cut the sockets out using a hack saw.
I haven’t used it yet, but I like that the volume is big enough for the largest of prints the Form 2 is capable of, and looks quite bright in there. The IKEA cabinet looks pretty snazzy too! Total build cost was about $125 (including turntable and shipping costs).
Yeah its true; I had 72 watts of the LED strips and one nail dryer and it worked great - until the strips faded to white. I am not sure if its the heat or UV light that kills them, but I suspect its the heat. My strips where on the inside of my enclosure, so they were subject to the enclosed heat, but with them on the outside of a jar I think they might last longer.
Can you show how you mounted the starter electronics for the 4-bulb clusters? Can you point me to reflective vinyl sources? This looks very nice. Will you have a temperature monitor so you can track time/temp?
Sure. I just used the mounts the boards came on (the nail dryer with the removable bulbs; the first link I provided). I circled the holes I used in red. I just put the mount in place, poked a small hole through the back of the cabinet, then used a couple of the screws removed from the dryer earlier from the other side. Super simple, I hope my explanation is clear - if not please ask for clarification.
Please excuse the mess, I haven’t got around to mounting the switches yet…
I used mylar linked above. For vinyl, check the link to @AtlasBrace’s thread.
I have thought about it, but I don’t think it will really be needed. I think it should be right around the optimal temperature from the heat of 108 watts enclosed in the cabinet. If its too hot, I will add some vent holes on the top. I will get some temperature readings inside soon.
Did the white LEDs still cure your parts? My understanding is that the coating on the LEDs acts as a filter, so that even if it fade to clear there will still be enough ultra-violet emitted to cure FL resin.
I just cured my first part with it. Works sooooo much faster my old setup with 1 nail unit, and since I had the part further from the light sources (I had it about as close as I could get it before) - the cure seems much more uniform.
Even fully cured both sides except where the center of the turntable blocked some light. Total time was about 3 hours versus 24 hours or so last time I did the same part.
Interesting … white LEDs are UV LEDs with fluorescing phosphors coated over, so, like billb said, one would think the output would still be there, unless the native UV spectrum peaks somewhere other than 395-405nm
UV is not obvious to the eye, but 405nm is. 405nm is not UV. It is part of the visible spectrum and violet in color. If you do not see violet, you have no 405nm energy. Formlabs resins are designed to react at 405nm (and others) because that is the wavelength of the laser.
Bottom line, no purple, no 405nm, no good.
Additionally, the LEDs fade due to excessive heat. This is mainly because there is no heatsink on the strips, a requirement of a proper LED system.
Range for photoinitiators for radical curing is wider than you think going to lower frequencies. We use 405nm diodes becuase costs are human, but best will be to use 320nm lasers because that zone BAPO and TPO will react faster and less will be needed. Using UVA or better UVB for postcuring is the best solution.
405nm lasers are cheap since Blue Ray players use this wavelength. It is also a good choice because they are no imminent safety problem with 405nm, so you Cana get by with not wearing UV safety glasses
I think that is an extremely dangerous statement. A 200mw laser can instantly blind someone - it doesn’t matter if the wavelength is 200nm, 405nm or 1060nm (infrared). The human eye might not be able to detect it, but more than 5mw of power can damage/cauterize the eye in an instant.
But speaking of safety; is eye protection recommended for using these 385nm compact fluorescent tubes?
3DTOPO makes a very important point. It is very easy to damage your sight with lasers. You should always wear eye protection when working with lasers. Eye protection is cheap and easy to wear. When compared to the risk of damaging your sight, eye protection is justified at all times with lasers.
I can attest to the fact that 405nm laser light is quite visible, but non-visible lasers are arguably more dangerous because people don’t realize they are being hurt until the damage is severe. I’ve seen someone burn their retina with infrared. At the time, no one had any idea there was a problem. A little later he was in great pain and had to worry about potential loss of sight.
Eye protection ALWAYS, no matter the wavelenght or power involved, also for nail oven, always avoid direct exposure. If you have no specific filter on you glasses, at least use sunglasses with UV shield.
To answer @3DTOPO and echo what @jevoltin, @BlueCat and others have said, please always use eye protection when using lasers and even UV lamps (used for curing chambers).
I work for a water filtration company. Our systems use UV lamps @ 365nm varying from 12w to 48w. When I first started here I was attempting photography of the 48w bulbs. I photographed them on for literally 3-5 minutes in total time. I knew it was moderately dangerous, but I figured just a few minutes would not hurt.
That night I ended up in the hospital having burned my retinas. It was a very painful couple of days. Luckily I did not do any permanent damage, but I sure learned a lesson from that experience. I went right out to Harbor Freight and bought some UV eye protection for my lab.
I wasn’t asking about lasers, in fact I pointed out how dangerous non-visible lasers are which @jevoltin echoed and his advice seems to be only regarding lasers not bulbs.
Anyhow, thanks for sharing your experience about bulbs.
