CellarDweller
Well-Known Member
Have you checked out the idea of a V-Groove RXI lens - this mixes multiple sources. The problem is the lens is very bespoke and is small....the the concept is cool
DIY COB reflectors
- Thread starter SupraSPL
- Start date
churchhaze
Well-Known Member
Bumping since this thread is more relevant than most of what's on page 1.
SupraSPL
Well-Known Member
Couldnt find these for a decent price but interesting idea, 140X70 degree beamHave you checked out the idea of a V-Groove RXI lens - this mixes multiple sources. The problem is the lens is very bespoke and is small....the the concept is cool
http://www.alibaba.com/product-detail/105mm-glass-led-lens-for-led_1988326619.html
CellarDweller
Well-Known Member
Very nice - am also looking at holographic diffusers. I think (based on as much reading as I have done of your fantastic contributions to this site) you'll be dead-set against diffusers given their impact on efficiency, but I have a bug in my b*tt about producing a uniform or homogenous light source of sunlight quality and with a high intensity.
So 2 downsides - they're pricey and they impact PPF (around 15%).
On another note and I know it's naughty because it's on the wrong thread, but on heat sinks and thermal management, are you:
A) Heavy base + long fins?
B) Medium base + long fins?
I am trying to find a good way of answering this question, but it seems the most "efficient" is to ask you and
@stardustsailor
sforza
Well-Known Member
Just goes to show you that it does no good to cast pearls before swine. After reading the excellent material and tests done by SupraSPL and the charts and graphs done by SDS, I noticed that the can of tuna that I was eating was round and my idea was formed.
It is not so much of a reflector, as it is a shield to help keep the light out of my eyes. I have some Cree CXA3590 chips, but I am new to this DIY LED building, so I wanted to cut my teeth using less expensive gear. I did buy a DIY kit and put that together, which along with all the great information provided free of charge by the mentors on this site, gave me the courage to try my hand at building my own DIY LED light, which I have Christened, Sforza's Sfolly.
It is not so much of a reflector, as it is a shield to help keep the light out of my eyes. I have some Cree CXA3590 chips, but I am new to this DIY LED building, so I wanted to cut my teeth using less expensive gear. I did buy a DIY kit and put that together, which along with all the great information provided free of charge by the mentors on this site, gave me the courage to try my hand at building my own DIY LED light, which I have Christened, Sforza's Sfolly.
churchhaze
Well-Known Member
Hey, it probably beats what Doer is going to make.. lol.. and it exists right now so you can grow plants with it!!
Win win!
CatSpeaker
Well-Known Member
sforza,
Is that the plate with the Dell heat sinks light?
How thick is it?
Thanks, CS
Is that the plate with the Dell heat sinks light?
How thick is it?
Thanks, CS
ttystikk
Well-Known Member
This is a dead end. The LESS between light source and plant leaves, the better.Have you checked out the idea of a V-Groove RXI lens - this mixes multiple sources. The problem is the lens is very bespoke and is small....the the concept is cool
The way to spread out light is simply to have more sources- COBs in this case- and place them so that intensity evens out by the time it gets to the canopy.
AquariusPanta
Well-Known Member
This one brings me back..
sforza
Well-Known Member
It is 3/8" thick. I had it sitting in the garage for years, so it is the same as free to me at this point. I was going to use it to make a custom rack for a motorcycle, but never got around to it. It was my idea to let the cobs heat up the plate and then let the fans cool down the plate. It actually works pretty well.
sforza
Well-Known Member
It is here and it is making a lot of light, but I am not the guy to try to figure out how efficient it is. I do like the fact that the driver that came with the Cree Surface Mounted Chips, which I presume are 42 ea. of 5 watt chips, has a dimmer so that I can adjust the brightness from all the way on, with uses more than 200 watts and really puts out the heat to just barely on. It takes about ten turns to take it from off to all the way on. One turn is about 100 watts, 2 turns is 160 watts, 3 turns is 180 watts, so obviously, the last seven turns do not do too much and get to taking about 230 watts.
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sforza
Well-Known Member
I like it that I can vary the amount of light put out my the center LEDs and since I put a switch in the hot wire going to the mean well driver going to the power the four cheap ass COBs in the corner, I can have just four lights in the corner on or just the middle light on, or all five of them blasting away to bring it on home.
Of course the Mean Well HGL-120H-C1050A is adjustable too, but not down to zero. Even the cheap little five dollar 12V power source to run all five fans is adjustable, within a range.
Of course the Mean Well HGL-120H-C1050A is adjustable too, but not down to zero. Even the cheap little five dollar 12V power source to run all five fans is adjustable, within a range.
Positivity
Well-Known Member
I don't know the numbers off hand but the new cxbs or vero v2 would probably be a substantial upgrade. Either way, looks nice and bright with the xpgs
You could use the cree tool or datsheets on their website to see exactly how efficient they are
SupraSPL
Well-Known Member
Assuming it was this kit I assume the driver is worth $45 so I subtracted that cost, the XPG 4500K R5 at 5W, 50C, should be about 27% efficient and cost $1.75/PAR W.
To compare with modern COB, the CXA3070 5000K BB bin, $40 at AliEx, run at 1.4A = 48.4% efficiency and cost $1.58/PAR W.
When available, the Vero 29 V2 5000K run at 1.4A is 44.6% efficient and cost $1.24/PAR W.
If you wait until Vero29 V2.0 comes out, you could swap the XPG board out and run a Vero29 on that driver. At 3.6A the Vero would be 36% efficient and cost $0.55/PAR W. A alrge increase in light and a profitable move if you were able to sell the XPG board for more than $29.
We have com a long way in a short time
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churchhaze
Well-Known Member
So... My 47% efficient 40W veg box has caused me to think recently... something about letting the fluorescent section go without jihading the hell out of it seems immoral...
You know how ISIS just smashed up all the idols in that museum? Well... I was thinking we can go over to the dumpster and smash up some fluorescent lamps...
Who's with me?
You know how ISIS just smashed up all the idols in that museum? Well... I was thinking we can go over to the dumpster and smash up some fluorescent lamps...
Who's with me?
churchhaze
Well-Known Member
sforza
Well-Known Member
I used four Rosewill RCX-Z200 heatsinks coolers in the corners and one Cool Master CPU Fan with a solid copper heatsink in the middle. The thick plate in the middle between the chips and coolers and fan is literally, a heatsink. It just sucks up all the heat. It is the job of the CPU coolers and their fans to cool off the plate. This way I do not have to match the surface of the COB to the surface of the
Thanks for the education, SupraSPL. You are always so helpful and kind. I don't know how you manage to find the time to do so much work on your projects and still help so many with their projects too.
It is a very similar kit that I bought off of Ebay.
http://www.ebay.com/itm/201110863207?_trksid=p2059210.m2749.l2649&ssPageName=STRK:MEBIDX:IT
So the numbers you ran are about the same. I am just running a tiny little grow because I like growing plants. Thirty years ago I was growing both outside and inside using Northern Lights and Skunk #1 seeds that I got from Holland. Then I managed to find a wife and have children and got jobs that required being tested for drugs, so I left that part of my life behind. Now I am near retirement and looking to start a new hobby. I still cannot smoke because of drug tests for work, including hair tests, which you cannot beat, but I do have a buddy who was my fraternity brother from college who I ran around with and did stupid things with. Somewhere along the line, from shooting up heroin probably, he picked up Hepatitis C. He did five years in the Federal Penitentiary system for coke, where he was diagnosed with the Hep C and was no longer allowed to work doing kitchen duties. He cannot find work and he cannot drink, so I give him what I grow for his personal use, since he still enjoys smoking ganja. He has been denied Gilead's Harvoni twice, but he is still trying to get access to the drug to cure his Hep C.
So being efficient and growing more bud is not a priority for me like it is for most of the growers on this board. It is more like a hobby that I can afford. A lot of ganja would be a bad thing for me.
But I really like fooling with the LED lights. I think making LED lights has now become my hobby with growing ganja now a secondary concern. I liked your idea of using that kapton tape and the paste you recommended to attach the chips to the aluminum plate. I can easily swap out different chips, but I will probably just keep making new lights. I used thermal adhesive to stick the coolers with fans to the top of the aluminum plate, so the coolers are pretty much there for the duration.
I have four CXA3590 COBS in hand and I have four Vero 29 chips on order, along with a CXB3590. I believe that you wrote somewhere that the CB bin were the most efficient chips in that series.
So I will take what I have learned and move on to see how much better I can get as I learn both by doing and by reading this board and learning from those who have more knowledge and understanding of the technical issues
tightpockt
Well-Known Member
I don't know why I'm having such a hard time finding reflectors...every other component is relatively simple and abundant except for the reflectors. I guess i'm spoiled and lazy and I'm kind of used to supra doing all the leg work..lol. I just want something that'll put out an 18" circle at 12" high and will snap right onto my cob holders..is that too much to ask!? However, I know the first word in this thread is DIY so I was thinking of cutting semi-circle like strips of aluminum from soda cans and folding them over to make a cone i just dont know how to figure out the angle