DIY LEDs - The write-up

[sammy113]

I dont know how I looked pass this post but thats a nice setup. That has to be so freaking heavy though. That is for a 125 tank?? Man Im gonna need a lot more lights for my 180 then?

Yeah, its heavy like hell. I'm not using XP-G's white like you but anyway the difference is not HUGE so you'll want more than that. I'd say each 24 LEDs bank could easily replace a 250MH but the problem here is coverage.

Your 180 is also 72" long right? its just probably higher?

 

[sammy113]

1:1 was too blue? Holy shiat, Im gonna have to buy a lot more whites then! I was told to buy 18 Royal Blues and 6 Whites! Yikes!

Dealing with the new XPG's and XRE RB is tricky. I'd rather stick to the Q5 and 1:1 ratio, then adjust whites or blues as desired for the perfect spectrum.

With that amount of blue you'll have a very blue rig though. Difference between XPG and XRE is 32 Lumens so no big reason to a a ton of blue cause the white is a little brighter than before. I'd do a 2:3 ratio. Don't know if it makes sense. For each 2 XPG whites, 3 Blues. Thats should be even less than going 1:2. In other hand, if you like better the crisp white look. then just go 1:1.

Color temp going 1:1 with all XRE is close to 14~16K so I guess doing the same with XPG's should be somewhere close to 12K

 

[der_wille_zur_macht]

1:1 was too blue? Holy shiat, Im gonna have to buy a lot more whites then! I was told to buy 18 Royal Blues and 6 Whites! Yikes!

It depends on a LOT of factors, so don't jump to conclusions without knowing the specifics. You'd need to know the model and bin of both LEDs to get an accurate idea. The overall intensity of a given LED matters, but so does the default viewing angle, assuming no optics.

For instance, a 50:50 mix of cool white XP-E with high-binned royal blue XR-E will probably look too blue to many people.

But, a 50:50 mix of cool white XP-G with average-binned roayl blue XP-E will probably look much much too yellow to most people.

Since most vendors are not selling high-binned royal blues (unfortunately!), if you're using XP-G for your cool whites, XP-E for royal blues, and no optics, a 2:1 ratio of blue:white is probably about right for most people (maybe around a 15kk MH lamp). If you're using XR-E for the blues and get a high bin, you might want to adjust the ratio a little more towards the whites because the XP-G has a wider angle, so it'll look less intense (especially on a small tank where the shallower-angled light is lost).

All in all it's a very personal choice which is why I try to suggest that people either get a few extra of each color so they can adjust ratios, or build a small test fixture using different combos before committing.

 

[mstng67]

DWZM -- What temperature do you set your soldering iron?

 

[der_wille_zur_macht]

For soldering the stars I usually put it around 320 degrees C. It's a 45w iron FWIW. The stuff melts lower than this temp but having a bit more heat in the tip helps when there's a lot of mass to heat up. For PCB soldering or other applications where there's much less mass involved I run it a bit lower. This is all for standard 60/40 leaded solder with a flux core. YMMV.

 

[mstng67]

I ordered the same iron a while ago, but have not used it yet, and am ready to retire the Radio Shack one.

 

[nitjt]

I set up a dimmer using a meanwell driver P type and a PWM it will dim to about 40% the it goes off what am I doing wrong? With the next build can I mix a few XP-G and XP-E on the same meanwell D drivers?

 

[der_wille_zur_macht]

The meanwell datasheet spec's a cutoff but iirc it's more like 15%. What sort of PWM signal are you feeding it (frequency and voltage)?

It's totally fine to mix LEDs in series with eachother as long as they can all tolerate the current you're running at and the total Vf is within the driver's output range.

 

[rickb]

Ok new question

I put some LEDs on a flat aluminum sheet but above 50% it gets too hot. I'm not too worried as I think 50% is plenty (48 blue & 48 white over a 90 cube). In the event I want to simulate nuclear conditions or high noon for an hour. Can I bolt an aluminum u channel to the top to help cooling, and if I did should I put the heat goo between them?

 

[der_wille_zur_macht]

Rick, can you give us some more details?

1) Dimensions of the aluminum sheet
2) Fans or other active cooling?
3) Your definition of "too hot"
4) Enclosure or mounting fixture the LED array is located in

 

[rickb]

Rick, can you give us some more details?

1) Dimensions of the aluminum sheet
2) Fans or other active cooling?
3) Your definition of "too hot"
4) Enclosure or mounting fixture the LED array is located in

Hey,

it's two sheets, each is 12"x24" each with it's own enclosure
there are small fans at the back
when I say hot you could probably do an egg sunny side up
I made an enclosure, it's probably got 3-4 inches inside between the aluminum and the underside of the enclosure. I can put up sone pics when I get home.

Right now I'm running at about 30% and everything is fine. Even 15% is bright and there I don't need the fans.

Thanks

 

[bstohrer]

I ordered the same iron a while ago, but have not used it yet, and am ready to retire the Radio Shack one.

I got the same one. Works great. Although I didn't like the tip that came with it (narrow conical). It was difficult to get a good contact angle with the screws in the way. I ended up ordering a few new tips. The angled chisel point looks like it will work best with the stars.

Bob

 

[bstohrer]

Hey,

it's two sheets, each is 12"x24" each with it's own enclosure
there are small fans at the back
when I say hot you could probably do an egg sunny side up
I made an enclosure, it's probably got 3-4 inches inside between the aluminum and the underside of the enclosure. I can put up sone pics when I get home.

Right now I'm running at about 30% and everything is fine. Even 15% is bright and there I don't need the fans.

Thanks

How thick are the sheets?

 

[rickb]

how thick are the sheets?

.125"

 

[sbleile]

I have a 335 Gallon DT that is 67"L x 35"W X 33"T, should I be making a fixture that is one 10" W heatsink or two... basically going side by side down the length of the tank?

I am basically planning to have a single tower of live rock with softies near the bottom going all the way to SPS near the top (as you would see on a natural reef) and most of the rest of the tank will be more of just swimming room for the fish... Suggestions?

 

[kcress]

rickb; What current? 50% is not a current.

A picture would be MOST helpful.

 

[kuzamu]

Hi, how would i hook up the pc fans? to the computer power supply? but how?

 

[vnguyen]

Is there any problem if I mix the XP-G R5 and XR-E Q5 in 1 string?

 

[akindbro4u]

what carclo optics should I use for xpg's running them 2' above a 18" tank. Maybe 3'. I was looking at the medium ripple, but not sure if they are tight enough. All LEDs will be spaces 2.0" apart.

 

[Dannyrotorpilot]

Yeah Sammy its 72 wide but 25 or so deep. I had asked if it was a good idea to mount the outside rows of LED's with a small outward angle to spread coverage or maybe use wider optics on the outside? I wanted to stay with a 1 inch fin so I could only get the 8 inch wide heatsinks. The 10 inch is just too heavy. Sammy is gonna need a crane to lift that thing! :bigeyes:

Also, I got a pic of my two different drivers and like I thought, one is NOT dimmable. Some one said they all are. They just dont have the dimming option. Look at the picture. I havent started even though I got all my stuff because I dont know which way to go about it. 36 LED's on a 8x16 inch piece seems crowded per unit no? Any input on that would be great! Thanks!

Yeah, its heavy like hell. I'm not using XP-G's white like you but anyway the difference is not HUGE so you'll want more than that. I'd say each 24 LEDs bank could easily replace a 250MH but the problem here is coverage.

Your 180 is also 72" long right? its just probably higher?