DIY COB reflectors

SupraSPL

SupraSPL

Well-Known Member
Yep just simple plastic painted white, nothing fancy. Even made a few out of cardboard cones painted white. Probably a fire hazard with high powered COBs but works great at 28W. A nice bridge until I figure out something more permanent. I put a few short ones on some of the COBs in the flower rooms that are on the edge of the canopy and considering putting them on every COB.

Actually it would be nice if I could make hybrid shapes that were shorter on the canopy side and longer on the aisle way side.
 
S

stock

Well-Known Member
SupraSPL said:
Yep just simple plastic painted white, nothing fancy. Even made a few out of cardboard cones painted white. Probably a fire hazard with high powered COBs but works great at 28W. A nice bridge until I figure out something more permanent. I put a few short ones on some of the COBs in the flower rooms that are on the edge of the canopy and considering putting them on every COB.

Actually it would be nice if I could make hybrid shapes that were shorter on the canopy side and longer on the aisle way side.
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i think it is time to buy 3D printer ,i bet it will very handy at this point ,newest models very nice
 
Greengenes707

Greengenes707

Well-Known Member
SupraSPL said:
Yep just simple plastic painted white, nothing fancy. Even made a few out of cardboard cones painted white. Probably a fire hazard with high powered COBs but works great at 28W. A nice bridge until I figure out something more permanent. I put a few short ones on some of the COBs in the flower rooms that are on the edge of the canopy and considering putting them on every COB.

Actually it would be nice if I could make hybrid shapes that were shorter on the canopy side and longer on the aisle way side.
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http://www.ledil.com/node/2/p/12264
http://www.ledil.com/node/2/
 
D

draz

Well-Known Member
Greengenes707 said:
It was about 110µmols with the reflector on. I didn't do it with it off and now it has been moved around. But I'll try to get one later for reference. The reason I didn't was because at 9" I was at the limit I wanted to see for intensity.


They are 94% efficient reflective. I assume a portion of light never uses the reflector so loss is limited. Plus they are AD's instead of AB's.
I have been running AB's in flower anywhere from 8"-14" with the drone, it's so spread out. The bigger bare cxa panel at
~18" and getting 900µmols...and >700µmols almost everywhere. The 90 reflectors are perfect for bigger panels. I need more holders so I can put them on mine.
Smaller panels/designs could use tighter 78* reflectors that could boost numbers closer to lens like numbers. Most lenses are tighter than 90* anyways. But the 90*'s reflectors have my pick for my needs.
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I'm surprised how low the #'s are at 12" off center. Have you ever taken a par reading at 45deg to horizontal? I'm wondering if the readings would be ~2x as high(though I haven't looked at these par meters before, they may have a means to capture light from angles).
 
Greengenes707

Greengenes707

Well-Known Member
draz said:
I'm surprised how low the #'s are at 12" off center. Have you ever taken a par reading at 45deg to horizontal? I'm wondering if the readings would be ~2x as high(though I haven't looked at these par meters before, they may have a means to capture light from angles).
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That is why I didn't go that far out.
Do you mean like tilt the meter towards the light? If so, yes I have done it and will give you higher readings...usually a lot higher. But for charts I only report the flat measurements.
 
D

draz

Well-Known Member
Greengenes707 said:
That is why I didn't go that far out.
Do you mean like tilt the meter towards the light? If so, yes I have done it and will give you higher readings...usually a lot higher. But for charts I only report the flat measurements.
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I do mean tilt the meter and point it directly at the source. I believe that a uMol/s of light energy at 45 deg would be more valuable to the plant than the same uMol/s coming from directly above.
I agree that it starts getting too complicated if add a 3rd variable to your measurements(but I'd still love to see it :) ) .
 
SupraSPL

SupraSPL

Well-Known Member
Ya I noticed that too, tilting the meter toward the light makes a big difference when off angle. The way my sensor is shaped, part of it is in its own shadow when the light is off angle. So tilting it allows the entire senor to be lit and I suspect that does give a more accurate reading of how much light is actually reaching that location. The shadowing problem is especially noticeable when the light source is close to the target and the sensor is far off angle.
 
SupraSPL

SupraSPL

Well-Known Member
Nice find, I have one of the 66mm on order hoping it comes in soon. The 44mm is big enough for the Vero18 and CXA3070 and probably even the CXA3590 Vero29, but I want to compare the results of the 44m with the 66mm on the big COBs.
 
Scotch089

Scotch089

Well-Known Member
So out of curiosity, how would these for people using cobs and star combinations... you'd have to match the stars with lenses...... -_- igh. But I do feel like I'm hardly getting any of my red down to the canopy with how few of watts I have in relation to the cxas, especially at such a wide angle. Maybe it's just how it looks. Spitballin here
 
SupraSPL

SupraSPL

Well-Known Member
I think you are on to something. I have a few COB + star modules and I have been wondering the same thing. I decided for now I will just put those modues in the middle of the canopy and try to keep them close. But when it comes down to it, I might scrap them and switch back to all-COB.
 
Scotch089

Scotch089

Well-Known Member
Cree needs to make us some 670 cobs :] I really don't like the idea of ditching the red altogether but I'm curious what to do with my next build... I think emitters like that only have lenses and no reflectors?
 
coolbreez1

coolbreez1

Well-Known Member
Given that diffuse light is more effective, why not consider some kind of DIY diffuser. Like opaque solexx placed 3 inches away from the LED COBS?
 
SupraSPL

SupraSPL

Well-Known Member
Will do Scotch

CB, I remember seeing that study saying diffused light is more effective but it was referring to greenhouse where light in "free". But indoors I suspect intensity comes first because if we tried to diffuse the light, intensity would decrease very significantly.

We can get some of the diffused effect by having overlap from several COBs running soft and maybe by having a slight breeze in the canopy to move things around. Another way to put it, if the undiffused light gets me me gpw, then I would give priority to intensity and we spread it as evenly as we can.
 
Positivity

Positivity

Well-Known Member
Scotch089 said:
Can you grab some pics some time? I need to go backtrack positivity's thread I think he had some as well
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I used ledil and carclos reflectors but they are a bit of a bitch to get on a 20mm star. Easiest was the ledil...tina or lisa...i forget..:mrgreen:.

With the ledil i took a little material off the bottom so it just fit between solder pads and screws. Solder had to be just right. But the run with the reflected 1a deep reds was a memorable one..
 
Scotch089

Scotch089

Well-Known Member
I see some lisas at 82° but only 9.9mm, and a Tina at 74° and 16.1mm. These are for the XPE not 2's, I guess I'm back to spewing stupid everywhere because I don't know how to size those things I just know the angle I'd want.

And pos I remember that run, I soo remember that run. Lol big reason why I don't wanna ditch my red. Hell. If anything I want more!
 
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