DIY COB reflectors

Finally got around to testing the 20% TiO2 satin spray, (properly sprayed in warmer temps) versus the 10% satiny/flat heat paint. The 20% is much "whiter" to the eye but slightly more gloss to it than the heat paint. The heat paint still wins hands down and dries faster/ less VOCs to off gas.

My guess is that the "gel" layer in the satin, semi gloss and gloss is interfering with the reflection.

Just wanted to pop in and share my recent addition thanks to this thread.
Top 1/4 of 2 liter PoP bottle and reflective tape

Great stuff as always, keep up the good work. We are not worthy lol

Side by side cxb3070s

Just wanted to share

Not sure if it's news to anyone, but Mouser has F13402_ANGELINA-W in stock for $8/piece. For use with IDEAL holder and CXA25xx (47°)/CXA30xx (52°)/CXA3590 (66°).

alesh said:

Not sure if it's news to anyone, but Mouser has F13402_ANGELINA-W in stock for $8/piece. For use with IDEAL holder and CXA25xx (47°)/CXA30xx (52°)/CXA3590 (66°).

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Last i checked future electronics has them for $5 each, minimum order of 5 though.

Do they have the reflector adapter for the 3590? I haven't been able to find them anywhere, like ever. Different model # adapter..

Positivity said:

Last i checked future electronics has them for $5 each, minimum order of 5 though.

Do they have the reflector adapter for the 3590? I haven't been able to find them anywhere, like ever. Different model # adapter..

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Future el doesn't have them in stock.
I forgot that they need adapters. Looks like Newark is expecting 3590 ones soon. It's fucked up that one has to order from like 4 different sites. I don't follow the logic of Mouser that they carry a reflector but no adapters and holders for it.

Stumbled upon this. I think I may try to make a scaled version.

https://www.rollitup.org/t/diy-reflector-for-smaller-areas-great-par-values.230773/page-2

bicit said:

Stumbled upon this. I think I may try to make a scaled version.

https://www.rollitup.org/t/diy-reflector-for-smaller-areas-great-par-values.230773/page-2

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Do it! Bigger Or smaller? Looks pretty legit for a diy

I had a little time today so I mocked together a couple of these...
At first I tried a soda can but the memory in the metal was too hard to deal with.
Instead, I used an aluminium cookie sheet...did a bunch of mockups with paper to get the size and shape I wanted and used that as a stencil. I'm not super happy with it but I was just messing around.
Here's some pics at 18"
Also..When looking at the light in my camera these waves that you see in the picture were pulsing across the wall but to the eye it's undetectable. Is this what you guys were talking about in that other thread?

Both lights powered up with reflectors attached at 12"

That looks pretty sweet!

Positivity said:

That looks pretty sweet!

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Thanks, I have high hopes! I was thinking about painting the reflectors white but I'll probably hang them as is. I bet that aluminium is pretty reflective and I'm really just trying to collect and focus on some of the scattered side light. I'm still looking for a source for those ledil reflectors that fit right into the holders though so if anybody know give me a heads up

60 degree 44mm lens vs 90 degree 50mm lens. From what I can tell all the 44mm lenses are "60 degree" even though they are often sold as 90 degree. Both frames have the same spacing for the mounting holes, but I cannot fit the 50mm lens inside the frame of the 44mm so they are not interchangeable. You can see how the surround on the 90 degree frame is thinner and the height of the glass is very different. The 44mm lens is 19mm tall the 50mm lens is 15mm tall.

SupraSPL said:

60 degree 44mm lens vs 90 degree 50mm lens. From what I can tell all the 44mm lenses are "60 degree" even though they are often sold as 90 degree. Both frames have the same spacing for the mounting holes, but I cannot fit the 50mm lens inside the frame of the 44mm so they are not interchangeable. You can see how the surround on the 90 degree frame is thinner and the height of the glass is very different. The 44mm lens is 19mm tall the 50mm lens is 15mm tall.

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I don't know why but I have a slightly negative opinion when it comes to lenses. I have no rationale for it either..maybe i'm worried about heat or light loss. Where did you find those...alibaba?

Yep, ali express and ebay. I agree, the ideal of losing 10% rubs me the wrong way, but as best as I can tell, the end result is the same as using a reflector. Either method is a huge boost for mid-hard running COBs.

The lens is more aesthetic and more options for mounting than reflectors in my case. I don't care about aesthetics for my lamps but if I am building for someone else I will put some care into the appearance. I like the idea of being able to swap the lenses. As far as heat goes, it is a non issue does not affect the temp droop and therefore does not affect the lumen maintenance.

Alright, so I found a cad file, picket up a rivit gun, tin snips, now I just need to find some aluminum sheet. It's been surprisingly difficult to find. I think if I scale the design to 1/2 size (based on the 14" lumenarc III mini) it would be a good match with an arctic alpine 11GT cpu cooler.

I miss drilled the SS dish I found. That's what I get for trying to do it free hand while burning midnight oil, have to go pick up another one. I didn't want to tap the heatsink again so I tried to center it around the LES and using the mounting screws for the LED to also hold the reflector.

I wonder if galvanized sheet metal would be decently reflective if painted with white paint? I need to go through this thread again.

Sure you could use galv steel fashioned into a cone, anything with 2 layers of good paint will be highly reflective. I haven't got a hold of a pro reflector to make a comparison yet, but I expect they will perform very close to DIY with Rustoleum high heat white 7751830.

I keep seeing these around too. Supra, would you need to make a notch or something for the wires from the cob (to get these close like the 1mm)? I'm trying to see a way of fitting them over cob holders (without one in hand ) It looks like the lens is pulled down against the mounting surface?

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How about just rolling cones out of aluminum sheets?

A cone laid flat is a pair concentric 1/2 circles (plus a little extra for overlap and pop rivet)


I can get 2 of them for every 1 square foot of .032 aluminum sheet. I can get 12 square feet for a little over $40. And that gives me the 24 cones I need for under $2.00 apiece.

I will cut it into 12x6 inch blanks, and stack them. I'll drill the pop rivet holes one one side only. That way I can do final alignment and drill thru, attach pop-rivet.

Now all the holes are the same. tape the blanks together, attach paper pattern and cut all of them at once on a band saw.

alesh said:

Future el doesn't have them in stock.
I forgot that they need adapters. Looks like Newark is expecting 3590 ones soon. It's fucked up that one has to order from like 4 different sites. I don't follow the logic of Mouser that they carry a reflector but no adapters and holders for it.

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OK, they're not DIY, and they're expensive. Plus nobody seems to want to take my money. However, the Ideal reflector adaptors (RA) and Ledil reflectors (LR) are so cool I want them anyway.

Let's look at the Ideal RA .pdf.

http://www.idealind.com/media/pdfs/products/specsheets/reflector_adaptor_ss.pdf

I can't believe rollitup still hasn't made hyperlinks inside of text more obvious....

According to that .pdf, the Ideal 50-2234C holder accepts the Cree CXA30 series COB's. That includes the CXA3070, which was very popular on this forum a year ago but is now second-hand news.

The second page describes their CXA35 holder, 50-2303CR. According to Ideal, the 50-2303CR will accept the 50-2300AN reflector adaptor. And the 50-2300AN adaptor will accept LEDil Angela/Angelina reflectors.

So, someone correct me if I'm wrong but it looks like the correct picks for the CXA3070 would be: COB holder 50-2234C, then reflector adaptor 50-2100LN or 50-2100AN. The "LN" version accepts the LEDil Lena/Lenina reflectors. The "AN" version accepts the LEDil Angela/Angelina reflectors.

For the CXA35 series COB: COB holder 50-2303CR, then reflector adaptor 50-2300AN.

The part numbers I've bolded above are all Ideal Industries part numbers. All we've done up to this point is spec the right parts that get you to the point of snapping a LEDil reflector into place. Finding someone who will sell you the LEDil reflectors is the next challenge.

Apparently Mouser has some Angelina-W's. $7.78 each - not cheap

http://www.mouser.com/ProductDetail/Ledil/F13402_ANGELINA-W/?qs=sGAEpiMZZMtokFGYinOTjgCXjBqj/iFRgkb0aNGooNEzxE39j1mKQQ==

And Newark has the right adaptor, 50-2100AN. $.88 each plus whatever ridiculous shipping Newark adds.

http://www.newark.com/ideal/50-2100an/led-adaptor-ledil-reflector/dp/39X0068

So it could be done right now, today, with CXA 30's. If you weren't particular about which Angelina profile you bought. An Angelina-W is roughly 45 degrees, -M is 28 degrees, and Angelina-S is 17 degrees.


For the CXA35, Newark has some 50-2300AN holders right now.

http://www.newark.com/ideal/50-2300an/led-holder-cree-cxa35-cob-array/dp/43Y4627

The 50-2300AN accepts Angela/Angelina reflectors so, again, you could do it today with CXA35. These supplies look to be spotty. And I wish someone carried a wider variety of the LEDil profiles.

EDIT: Someone on another thread mentioned Arrow. I looked. For the CXA30, Arrow has reflector adaptors 50-2100AN and 50-2100LN. They don't stock the 50-2344C holder. For the CXA35, Arrow stocks the 50-2303CR holder right but none are on the shelf (backorder is available) and they don't stock the 50-2300AN adaptor. Arrow has one LEDil reflector, the Angelina-S. I'm guessing that the S might be too much spot for the application...