Building a Home Made LED

[rrog]

I built my first panel for the cool temps. The efficiency was a plus. I wouldn't go back to HPS again, personally for a few reasons. I'm planning on building several panels so they can be independently articulated. So cost becomes an issue.

I've thought of buying full lengths of heat sink and cutting myself. I'd reflow LEDs if it was a significant savings. Hence my question about the dropping cost of XM-ls.

 

[PetFlora]

For flowering I think a 7 diode mcpcb with one NW in the center surrounded with 6 WWs , flip that for veg

 

[tebos]

Okay, reflowing onto copper PCBs is the way to go if you're a perfectionist or a overoptimizer

The price difference between XP-G/2, XP-E/2 etc. isn't that much, I think it's fair to say that price difference isn't going to be that huge.

 

[positivity]

Well when it's time to update leds you only have to buy the leds and drivers instead of a 500 - 1000 fixture so there's a pretty big savings there...that's what I'm looking at

Tebos> I'm definitely in the over optimizer category..lol. I was looking for a copper sink pad for the ledengin 5w 660nm to go with the xmls but they don't seem to have one.

I'll be trying the hot plate method or glass top stove method too...maybe buy some cheap leds to practice with?

One thing if anyone can help. I contacted heatsink USA for the 10.080 sink. They said they can mill it and tap for 4-40 screws. But they need a detailed sketch up. Anyone know off hand the distances from holes and depth of holes so I can try and send them something. It would be really nice to have the sink finished by them and not have to worry about breaking screws and bits

 

[rrog]

The stars with the Cree XM-L's from LEDGroupBuy, per my build notes:

Holes were spaced at 19mm centers (DOUBLE CHECK). 11/32" deep

#42 numerical drill bits to cut the holes. I have a big drill press.

#4 x 3/8" self-tapping button head screws.

Insulating washers 16FW004032 and are only .031

The screws, washers and bits were recommended by Rives and proved 100% right on.

EDIT: I added 1/32" to the above hole depth. That's what I'll be doing next time.

 

[SB7]

rrog,

For your next panels what's going to be your ratio of NW to WW ?

I'm vertically challenged ( LOL) so I'm still liking the 1:1 ( higher blue) for an all purpose setup.
I'm about to build 2 x 200w 10.8 x 30 ( one Inventronics 200W per heat sink + 1 60W halogen ) ( This to cover a 2 x 3 ft area. currently lit with a 400CMH )
It'll be interesting to compare the two types of lighting.

 

[rrog]

Good question. At this point I might look at blending in more blue. The CW doesn't put out much. Not like the WW

I'd be tempted to use all WW, supplement some blue with specific LEDs, as well as supplement the ~730nm

 

[the.rise]

I have noticed the opposite while using only LED, however I am running 9 730nm diodes in a 7 spectrum panel. I believe that could account for the difference. Flowering times are down, the plants start producing buds after 14 days of 12/12. If pistils were not showing before, the plant shows pistils < 48 hours after entering the tent. The first harvest was easily 10 days ahead of schedule compared to the same cut under 1k hps in hydro.

I believe you can damage the plants with an incorrect spectrum, or just too much light causing photoinhibition. But there would be signs of this well before the expected harvest window passed.

I don't know how much research has been provided in the past 40+ pages of this thread but I have a plethora of links about photosynthetic responses to all ranges of light output. I went on a deep dive into several university studies and want to share what I believe to be 100% true.

First- 710-730 nm are used in non photo-periodic plants to trigger flowering (or extend perceived "daylight" in photo-periodic plants). It would make perfect sense that in a plant such as MJ there would be a response to this spectrum in the form of forced flowering. You definitely don't need as much as you have supplied because plants don't photosynthesize light that far red. They react to it as part of their sensory network but do not use it. It has been shown that far-red can stimulate plants into producing thinner, larger surface area leaves - none of these plants are similar to MJ though.

Second- plants only get damaged when you start adding too much UV light. They bleach. White LED's do not supply all that much UV. You can buy stuff with 410nm peaks that will drop off into the high 380's which is all the plant needs on occasion. Almost any other wavelength beneath the sun (pun intended) will give you positive results. Recent studies on lettuces and soybeans have found that UV-A (and deep blue) decreases inter-nodal distances (shorter stems) as a cryptochrome response mechanism. Cryptochrome stimulation has also been related to increased leaf mass, if not surface area. You only need light doses of UV-A and UV-B to see the beneficial side effects although they are photosynthetically active. Set those LED's or lamps to be on for short bursts or at lower drive currents. UV-B has been studied in Basil as a way to produce more flavor through enhanced resin production. originally it was thought to be from stressing the plant, but I believe it's just a response from the light perception network of all plants. Too much UV-B will kill your plants though so be careful!

Green has been reported to be beneficial by piercing through layers of canopy (LED's are beamy with optics) and gets absorbed by lower leaves as the wavelength red shifts. If I'm not mistaken, carotene is the major absorber of Green light and is very important in maximizing growth. At light intensities surpassing 600umols/m2s1 there is a perceived correlation to increased dry mass just by adding a green source. Green has also been associated with resin production in Basil and increased leaf area in Tomato/Lettuces.

Warm white is the most photosynthetically active white LED and should always be supplemented by Deep Blue/Blue so you can hit that 430-465 Chlorophyll B peak.

I've been tooling around with LED's for several months now and have yet to start side-by-side testing of different spectrums. My 7 channel with a single UV-A at 18/6 made some incredibly happy basil so far

I've been gone from this forum for several years but I'm going to begin frequenting it again. I'll attempt to answer any questions I can.

 

[the.rise]

I have yet to find any substantial research on flowering plants, just vegetative growth. My heart is leaning towards heavy red/far red and I would like to suggest building rigs for veg/flower like people use MH/HPS. For flower I think equal parts UV-A and Green (of photon flux not luminous flux), 80-85% Red light, with a balance of blue (not deep) and warm white will be the best for MJ. When you start looking at spectrometer data for arrays, it's probably best to mimic the PAR spectrum.

Side note for why I suggested UV-A: The far red response curve has a second relative peak from 390-410 and I'd be interested in seeing if we can use this to enhance resin production. My basil had much more robust odor under supplemental UV-A. Thats resin.

 

[habeeb]

Does re-flowing yourself pay off?

I've done testing with my light meter,

and find even reflow DIY, makes more light then buying them. don't hold me on the numbers, as I don't remember, and too busy to check right now. these were with aluminum sinkpad stars, just got in the copper ones, but not sure I can test them against the aluminum anytime soon, as there on different panels.


I find my logic in the area to: use best LED out, use fans, and you'll have one of the best setups = more light output. also having it years before any manufacture of LED will have them in there system. but this also comes at, cost / time / expense.. but I find in growing, the job is never done

now, if someone would tell us the best color setup to use..



oh, one thing to note on DIY, is I've found in my testing, the LED with more light, was when I did an experiment with solder layout. I did a line across and then like spreading out over the surface, the ones with the spread out solder made more light.. could be a fluke though, as I only tested 5 of each, it was odd though, as I thought the each LED put out different amounts of light, but in my testing they all ended up very closely the same, I didn't see wide variances as I was expecting.

the DIY made less light at very very low output vs. then bought. but once you start pushing any light into them, the DIY overtake.. but this is good to know, as a DIY is not as good as a pro reflow, but the stars give us a advantage that you can't buy ( well not yet ).

I find it's best to go into this, with a non ending end. your led will be old if you use it or don't. using it will decrease light over time, and even time will bring out new led. know what your wanting, and have realistic expectations, and you'll come out better then being grumpy missing your mark or having fantasies.. DIY is well... DIY

 

[habeeb]

edit

 

[habeeb]

figured I would put some pis here, as I don't plan on many more through the grow..

here's the xm-l2 WW doing it's thang .. haha , 35 watts a square foot. just did to see, as I'm tired of thinking.. I'm a doer. I can't say what strain it is.. it's also going for seed production, so I don't do weight.. never have. I can tell though by seed count how good it's going to do, as it's a marker to judge as I know seed counts on plants.. I also grew this plant long ago with floros, so I can judge it to that also, but already it's so much bigger then when I ran it already! the plant is small because I use small pots for veg ( solo cup size ) , it's looking like normal sized internode as this strain stretches branches like that exactly. so it looks like we have enough blue in flower with the WW, but time will tell if I like it.

well here's it at ( who knows ( would guess it at 5 days flower based on watering ), don't write stuff down, also experimenting with organic again, so I did.... peat moss..... ( I'm a coco lover ) but also doing some organic testing with it, and it looks promising )



and again 3 days later.






thing I'm noticing, is it hits so close to the light, so some measurements that close put it at 3300 PAR !! ( li-cor par meter measured ) . I find that insane, and no bleaching as maybe each color is not powerful enough to bleach ???

I already feel some 660 would do it good, but that would need re-designing the whole system, the way I want it for dimming the reds so you have a nice color to work with.. also I would make it more powerful, but lets see how this does first I guess...


here's the bars at 4000k color. I'm liking it. having some Mg problems with the back plants, but forgot they were cal/mg hungry gals.. that AC to DC driver is nice, as I'm powering the bars with the meanwell dc drivers, very small, they get hot, but being on the bar they stay good temp. it's super light and small I think for being a 600 watt supply decked with features. I got it so I can add more on later to supply the veg tent with all LED hopefully.


so I'm just busy sorting coco, and organic, and everything led.... it's keeping me busy..

 

[positivity]

3000+ par, no bleaching, all warm white...looks good to me!
As nice as 660nm sounds..I hate bleaching. Probably keep it on the light end similar to Area 51 if I ever get to a big panel

Thanks for the info on ww, that was much needed. If the panel grows them that nice with ww I don't really see a need for nw

Looks like its DIY from here on out...

 

[PetFlora]

For future builds with single diodes or small chips, staggering the rows will provide more uniform spectral distribution

Which Spectrums Indeed

I just completed an experimental grow: 2 clones using 4 @ 20w LED tubes (WW/3000k). A mix with 4000-5000K would be nice. I used 1/4 NW (~5000k) until past mid-flower then 4/4 @ 3000k

Same clones under 324w HOT5 mostly red bulbs, but not much 660, produced much fatter calyxes, although tric production was very similar

Not seeing fat calyxes I decided to add my ufo 90 R/B 8:1 over the clone on the left for the last 2+ weeks, to no visible benefit

Clearly I need ~ 50+w more @ 3000k watts, or probably 2400-2700k (loose translation = 620-650) but...

View attachment 234499 View attachment 234500

324w HOT5

View attachment 234501

 

[rrog]

Little flarfy yet. Might be the light? Otherwise, I think he's doing a great job. First grow. 1-2 weeks left

 

[repuk]

Hi!

I'm doing my second grow with my DIY LED lamp, see my sig for the link, all the details are there.

My current setup worked very well, got 151 grams, (HML measures 148 Watts) so hit the 1gpw without problem.

However, the most sativa leaning girls, the Atomic Hazes, had fluffy buds and poor resing production. The Amnesia haze had good production, and decent buds thought nothing to call home about.

The somango however developed huge, hard nugs, almost half of the production came from that plant.

I'm convinced I need more deep reds, and that's what I'm going to add, 60W of deep reds, but using 3W chips, in another HML setup, intended to be used at the same time.

With my current HML I can put it about 1in from the canopy, and never got bleaching. I want to keep that "feature", so the deep red driver will be dimmable, I believe that along with they being 3W will make that possible.

The current run, 4 Panama D.C. (Panama x Deep Chunk) clones have grown incredibly fast under my first HML alone, I will switch to 12/12 this weekend and hope to add the 2nd deep red HML in two weeks, will let you know how it went!

 

[woogille]

hi,
some pics of my DIY-ledlight. build two of them. 30W each.

1 Cree royal blue(450nm)
4 Cree neutralwhite
6 Osram GD+ red
6 Osram GD+ hyperred
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SK44 Heatsink (159mmx200mmx15mm); 2 silent fans 60mm
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led-Layout & Light
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hey friend -
may i ask how much did the whole parts cost you ?

 

[rrog]

repuk-

Adding red really improves things. The panel with WW, NW just doesn't stretch unless the lights are raised. So adding red via 60W halogen as well as raising the lights allowed them to stretch nicely.

 

[habeeb]

RROG,

will you have your friend next time test without the halogen by chance?

it would help us figure out more about stretch cutting out anything non led..

I think this would do wonders for the community, as maybe the reds need to be on a separate tier then if they do cause stretch, but from my research once again, into the topic of red/far red. stretch is mainly caused by lack of red.. if I read it right..

I am guessing the stretch just came from overall lower light levels? not sure what levels of light your panel is putting off, but let's admit, led's without lens' are not piercing intensity..

 

[rrog]

I think the huge light was part of the problem. 300W actual output. I'm certain not raising the lights was keeping them squat, or perhaps more accurately not encouraging any stretch. His first grow was like super-dense christmas trees, and not the stretch one would expect at all.

No question the two variables have been blended in this grow (added red + raised lights)

Current grow:

ROLS soil, of course. Note the clover living mulch... plants seem to dig it, no?