DIY LEDs - The write-up

[SimonSKL]

Sorry to cut in. I am still in the design phase of my LED fixture for my 92g corner tank. It's amazing how quickly the LED technology has advanced since the first post by Soundwave more than a year ago. Most of what you guys have been talking about just way over my head.

I have incorporated many of the suggestions earlier and I hope this is a better design than before.

I will use 1" U-Channel aluminum strips as my heatsink and will increase my CREE Q5 LED counts from 48 to 72 with a 1:1 ratio of CW and RB. The front 4 U-Channel strips will have 12 LEDs each and the back 3 will have a total of 24 LEDs. The spacing between the LEDs on each strip is about 2.5" and the distance between each strip is about 1.75" (~ 2.75" between LEDs center to center)

The aluminum strips will rest on 4 aluminum T-tracks to allow me to adjust the spacing between each strip. I would also like angle the front strip toward the center of the tank to keep light from touching the front glass. I haven't figured out how to do that yet. The whole aluminum structure will rest on a 1/4" clear acrylic which acts as a splash shield.

Again, any comment or suggestion is welcome and thanks for your help!

 

[der_wille_zur_macht]

I haven't figured out how to do that yet

Cut little triangles or tabs from a flat piece of stock, bend to the angle you want, and screw them on the bar.

Or, if you mount the bars "from the ends" with a block of threaded aluminum in the end of each channel, you can bolt them to mounting plates on the sides of the hood at whatever angle you want.

 

[ReefEnabler]

Here are some comparison shots of different LED optics I have.

These should probably only be used to get a general sense of the type of spread the optics have, not as a stand-in for empirical data.

They were taken with shutter sped 1/20, f=16, ISO=640.
1 x Cree XR-E royal blue @ 700ma from xitanium driver. It's only using ~3.3v so its probably running at less than 700ma.

61" from LED to ceiling
For size reference, the circular moulding on the ceiling is 24" in diameter.

No optics reference image:

Next up the Carlco Tight lens with 13deg FWHM which looks like this:

The extreme banding is a camera artifact because this image was so much brighter than the rest. The RAW format didn't capture this banding but isn't as comparable to the other images (plus it was cropped before the resize!), click here to see it. You can definitely make out the shape of the die with these optics, and yes it is very very bright to look at

Gives a pretty harsh-ugly spread when viewed by itself, but with shimmer on a tank you can't really tell. Still I'm sure there are better ~13deg optics out there.

Next up the Carlco Ripple Medium, 16deg FWHM (looks like the narrow but the surface is rippley not smooth):

And this is the Carlco Ripple Wide, 44deg FWHM (optic looks identical to the medium, in fact the whole reason I started taking these photos is that I mixed up some medium/wide lenses and couldn't tell them apart visually without A-B photo comparison):

And finally the RadidLED 60 degree optics, which look like this:

I don't know who makes those so I'll just call them the RapidLED wide optics for now.

The best way to compare the images is to goto http://www.worstkind.com/aquarium/leds/ and click through all the images and use your browsers back-fwd buttons so you can see them swap, much easier to see differences in brightness.


After comparing them, I think the RapidLED 60 optics are much better than the Carlco Wide optics. The Carlco wide is a fairly uniform brightness across the whole spread, without much bright spot in the middle. Might be perfect for somebody, but to me it looks like the RapidLED 60 gets about the same coverage plus a bright even spot in the middle.

I just ordered some RapidLED 40 degree optics to compare to the Carlco Medium.

Right now I have all Carlco Wide's on my LEDs but I am planning to swap most of them out for Rapid LED 60 and Carlco medium.

 

[ReefEnabler]

Or, if you mount the bars "from the ends" with a block of threaded aluminum in the end of each channel, you can bolt them to mounting plates on the sides of the hood at whatever angle you want.

That's pretty much what I did. My mounting plates are each 4 short pieces of L shaped aluminum riveted together, with a hole in each for screwing into the tapped heatsink strips.

You could use a block of aluminum in the ends of the channels like DWZM said, or you could just take some L-shamed aluminum and rivet it onto the end of your U channel, and drill a thru-hole, and attach your mounts with screw and bolt instead of tapped threads.

 

[kcress]

Thanks for those photos Ryan.

 

[Skeptic_07]

yeah, thanks for that contribution ryan. Those type of shot comparisons are helpful.

 

[dnahas]

:thumbsup: Thanks for the optics pics !!!

BTW what happened to your TV? Care to share some info on that back light?

 

[ReefEnabler]

double post

 

[ReefEnabler]

no problem. I want to re-emphasize that I'm not implying that the RapidLED 60 is more efficient or puts more light into the same footprint than the Carlco Ripple wide. Just that the light distribution is smoother and more easily blends together as opposed to the appearance of overlapping spotlights you'd get if you spaced out the leds more with Carlco wides. I can wire up a few to show this. I'm curious if the Carlco Frosted Wide is more like the RapidLED 60.

BTW what happened to your TV? Care to share some info on that back light?

ah you recall the post I made about the sony rptv that crapped out on me last year? Unfortunately the light engine failed just after the warranty expired. I forget the exact name of the part but it was the three colored films responsible for the color of each channel. They basically used cheap plastic films way too close to a high wattage bulb with insufficient ventilation. Sooner or later the films show splotchyness and fail... (btw here is what that looks like after a few weeks of blue spots slowly showing up)


anyways I ditched it, went to a kuro plasma and never looked back

 

[widmer]

Thanks for the optics shots. It's fun to see the 13 FWHM carlco; I would have gone with the 8.4 FWHM from ledsupply if the folks over at candlepowerforums.com hadn't told me that it projects a die.

 

[HeneryH]

I was tinkering with some modeling. Here is a 20mm Cutter 3-Up MCPCB for the XPG and an LED heat sink from Aavid Thermalloy (which I haven't priced yet). Just tinkering but if anyone wants the SketchUp models let me know.

 

[ReefEnabler]

man... I ordered more MC-Es from dealextreme last friday, and it still hasn't even left honk kong. In fact I had no idea they were coming from honk kong or that it would take this long.... I'd rather have overpaid at ledsupply and had them a few days ago than having to wait this long, I'm going nuts

 

[widmer]

Yea the Dealextreme XR-E's took five weeks for me. In retrospect, I would have just paid the $20 difference to get them a month sooner. I feel your pain...

 

[der_wille_zur_macht]

I've had a bunch of people PM me since I made that statement about feeling nervous regarding Cutter's shipping - all reports seem to be that it's quick and reliable. FWIW they have REALLY good MC-E pricing. And pretty good pricing on other LEDs, too.

 

[ReefEnabler]

ah thanks for reminding me cutter has the MCEs... when I checked before I thought they only had the MCE chip itself without star mounting, but it seems they do have stars for 15 bucks

curious though, they list color choices as Neutral 5B and Cold.... Using the chromacity chart 5B looks to be around 4000-4300k....

and their "Cold" looks like it could be a MC-E-Color made up of four different color dies, since it the only mention of "Cool" or "Cold" in the whole bin sheet is the A1 block covering WC, WD, WF, WG chromacity....


*EDIT* Brain fart: I think theres 2 separate order drop-downs on the Cutter MCE page... the top one is the MC-E color multichip, so even the white ones are made from mixing.... the second order drop down is further down the page and has all 4WT chips in the name, and also has cool white in that drop down


link

The M10 kit seems to the the most cool-white they have, it's in the WC chromacity region or just under 7000k.

over here, somebody took photos comparing WC (~7000k) and WG (~5700-6300k) MC-E.... fairly noticeable difference

 

[The Grim Reefer]

Gads, if the disciples of the T5 catch me posting in a LED thread there will be hell to pay

Have any of you tried the warm white LED's in a 1 to 1 combination with the blues? Those seem to me at least to have more spectrum. Also wonder about using a 50/50 mix of Blue and Royal Blue on the blue side of things to broaden the blue range spectrum a bit.

 

[ReefEnabler]

I've mixed Blue and Royal blue at a ratio of about 3:1 just to mix up the spectrum a bit.... I like the way it looks but never did A-B comparisons or anything... definitely better than my previous experiment of mixing RB and cyan... I thought it would look nice and 'deep sea', but the cyan just washed things out a bit.

also I prefer the cool whites personally. Next to a blue or even royal blue light they appear fairly warm in color and they are more efficient than the warm-whites.

 

[der_wille_zur_macht]

Gads, if the disciples of the T5 catch me posting in a LED thread there will be hell to pay

We won't tell.

Have any of you tried the warm white LED's in a 1 to 1 combination with the blues? Those seem to me at least to have more spectrum. Also wonder about using a 50/50 mix of Blue and Royal Blue on the blue side of things to broaden the blue range spectrum a bit.

Haven't tried warm whites, but honestly don't see a need - the cool whites are "nice." Coral growth and colors don't really point to any sort of deficiency in spectrum. Warm whites are pretty warm - I'll probably try them on an ATS at some point, though.

Plain blues are OK too, I've tried them mixed with Royals and Cool Whites. But again, I don't really see a strong need. They're pretty much a "sky blue" color, maybe like a 20kk MH, but have no "pop."

One thing that separates LEDs from other lighting technologies is that the colored LEDs are VERY monochromatic. The spectrum you get from them is very narrow. This can be a good thing or a bad thing. In the case of Royal Blues, it's a good thing, because the peak is right on the edge of visible, so it gives a very rich color, but it bleeds down low enough to give GREAT pop, too. In the case of the plain blues, the narrowness is (IMHO) kind of a bad thing. They're not low enough that they pop at all, they just sort a make things blue. Maybe some people will like that, but it's really not that exciting to me. I've found that if you get over 20% plain blues (plus or minus) you're either losing royal blues and losing pop, or you're losing cool whites and losing the wide white spectrum.

It really just boils down to many people really liking the standard issue 40/60 - 60/40 sorta range of cool whites to royal blues, but there's really a vast degree of flexibility for people that want to fine tune. Besides just picking a "named" color, you can also pick color bins within that name, to get a pretty exact control over color.

 

[SimonSKL]

Just curious. Does anyone know of any group buy on CREE Q5 CW and RB or Mean Well drivers anywhere here at RC or other reef sites?

 

[ReefEnabler]

I'm not sure I had the same results with just Blue LEDs.

On my wife 20g nano, we initially used only Blue/White since we were using 120vac "led-bulbs" and RB wasn't available... we got really nice actinic pop from various corals using just the blue lights. Of course later we added 4 royal blue crees and the pop from those was much stronger, but I don't think its entirely fair to say Blue leds give no pop.