Building a Home Made LED

[maryjane481]

Cree XM-L are here.

Cree XM-L are here.

Tenthirty, you can buy Cree XM-L star mounted from ledsupply.com
for $10.05 each

 

[maryjane481]

Edit, I forgot to mention they have warm white.

 

[luvdemshrooms]

I wish I could find some WW XM-L's on stars somewhere.

Mouser has bare stars and WW XML's.

Mount them yourself if you have some needle nose pliers, solder paste and a hot air gun.

Stars: 951-804936

WW XML's: 941-XMLAWT0000LT30E7

 

[rives]

I don't know that I would want to try using a heat gun, but an induction hot plate works very well.

 

[luvdemshrooms]

Well, you guys don't know me, but I wouldn't suggest it if it didn't work.

Just heat from the bottom (like your hot plate), and after the solder flows give it 2 - 3 more seconds.

The star prevents the hot air from directly hitting the LED.

 

[tenthirty]

To solder one diode, maybe. To do ten, not so much.
I could burn the shit out of myself, not to mention how many diodes I could ruin.
"just because you can, doesn't mean you should"

Anyway the trigger has been pulled and the 9/9 XM-L's and XP-G's and all the fix'ins are on the way.
$200 more or less to my door.

 

[willyweed]

good work guys.over in the uk the heat from the hps is a must from about now until next may just too dam cold otherwise ! someone i know works with led's and has designed a more efficient led, but says he wont get rich off it as the industry is moving at such a fast pace that it would be outdated by the end of this year, but the tech still has a long way to go,years before it gets cheap enough to become a viable replacement for hps. i hope you prove him wrong! goodluck

 

[tenthirty]

Unless your talking the Gavita double ended 1000w unit,
my HML bests every HPS out there in both lumen and PPF per watt,
and the quality of light is much better suited to the action spectrum of the plant. Not to mention that the light is pretty much coherent.
The next model will be much more homogeneous and there won't be a big red spike at 660.

Devil's advocate.
On the down side we're sport'in $2.50 per watt.
That would be $2,500 for 1000 watts,
and you have to build the things.

But................
So far the study is showing that I will be able to replace the 1k HPS with
about 600w of led, because of the action spectrum match and the more even distribution of light.
I already know the quality is better (everyone raves).

Lets say, right now, today, The system produces roughly .5-.7g watt every 2 months
on a total of 1k mixed lighting and it does this consistently.
We're gonna find out if we can maintain or best this figure over time and see if less than 600 watts of led can do the same thing.
There is one game changer in the work, the 315w agro bulb. Which, if it falls into my lap, I will replace the 600w HPS with it, post haste.
Just the whole thing of the plasma arc, just blasting out photons, is kinda romantic, like the sun. Besides, the spectrum is really good, or should be anyway.

Pic request

First group is day 13 after flip. They were mercilessly sog'd yesterday.
I was too busy to do it over a few days, so we're talk'in 5 or 6 big branches per plant were removed.
They sure do look awful happy for just hav'in the shit trimmed out of them.



Day 44 group

 

[Weezard]

Howzit 10:30?

This statement is confusing;

"Not to mention that the light is pretty much coherent."

What do you mean by that?

Aloha,
Weeze

 

[hempfield]

"Not to mention that the light is pretty much coherent."

What do you mean by that?

The human eye is much more sensible to green light (which often is missing from LED panels) and the focus is much better on a full spectrum rather than on narrow wavelengths.

This is why we see better in white light

I assume this is what tenthirty trying to say by 'much coherent'

We all know that it's much better (comfortable) to work in a grow room in white light rather in blue, red or mad pink light.

 

[willyweed]

so let me get this clear in my head"heat is not light energy ?"why is heat not put into the equation ? in my post i mentioned about the cold weather which is why they will not and have not taken off over hear. we need the heat from the light to stop the plants from freezing to death .also i did not see the costings for your time to source the material and construct it? .its ok to overlook the heat when its 80/90 degrees outside but that does rule out colder climates unless heating is also provided,at extra cost and with air extraction it is harder still and costs even more to heat.yes it may be great for you but not great for me that is what i am trying to say and i gave my reason why ! many thanks

 

[hempfield]

so let me get this clear in my head"heat is not light energy ?"why is heat not put into the equation ? in my post i mentioned about the cold weather which is why they will not and have not taken off over hear. we need the heat from the light to stop the plants from freezing to death .also i did not see the costings for your time to source the material and construct it? .its ok to overlook the heat when its 80/90 degrees outside but that does rule out colder climates unless heating is also provided,at extra cost and with air extraction it is harder still and costs even more to heat.yes it may be great for you but not great for me that is what i am trying to say and i gave my reason why ! many thanks

If the heat/cold is the only problem, just buy a ceramic heater and the problem is solved

Running on cold climate it's just a particular situation when maybe the LED light is not the best option if you are not interested to invest in medium control units.

But using a light source for heating it's not the most convenient way to handle this problem. Taking advantage of the heat created by a HPS is other story.

 

[willyweed]

also tenthirty you say you are going to change the 600 watt hps 95000 initial lumins to the 315 watt agro bulb 33000 initial lumins still seems like a big drop in lumins can you not get mixed spectrum hps bulbs in the usa? also do you use the 600 watt super lumin switch,it gives an extra 60 watts,which is great on the second or third run when the bulbs are a bit fried good luck anyhow.willyweed

 

[willyweed]

hempfield i am only wondering if the energy used from the heater would be better used in lighting. in the dark hours i have underfloor heating under my tent works great.i did start off putting my electric blanket under the girls but it was too cold in the bedroom so i had to nab it back and find a better solution thankyou for having a bit of patient's with me ,still finding my feet on this site .looking forward to getting in the chat room .good luck all and thanks for your wisdom !

 

[PetFlora]

Reves, wnw wins. Will be placing the order today.

PetFlora, ultimately there will be 3 rails spaced at 1ft. 3 to cover a 3x3.
So your right on the mark.
What do you think about the 660nm leds causing the stretch?

Keep in mind my 660 experience is with HOT5 1/8 @54w. Not sure whether my 3 yo ufo 90 has 660 as the company is not saying. It is 9:1 RB, so it is likely to have 'some' 660.

On another site RIU it is suggested that 660 (without some 720- 740) is counterproductive. In my HOT5, the Indica/Sat X plants did not want to finish (used both a Coral Wave + 660 + other 6 other bulbs), and tric production was medium. I had not prior experience with this X so deducing anything is a crap shoot.

From what I have read, 660 is really not needed when sufficient 630 is present. That said, if I recall correctly, Weez is very happy with his results using mostly/all 660 for his reds. So perhaps it is strain dependent. Summing it up I would have 660 on a separate circuit, so you could turn it o/o independently

 

[medmaker420]

Has anyone actually seen real negative effects by using the 660's or any other specific spectrum? On RIU do they have documentation on the negatives? That would be worth researching a bit.

 

[tenthirty]

Howzit 10:30?

This statement is confusing;

"Not to mention that the light is pretty much coherent."

What do you mean by that?

Aloha,
Weeze

Here ya go Weez.

http://en.wikipedia.org/wiki/Coherence_(physics)

When using white leds the light is rich in harmonics and has a smooth curve across the band.
When mixing multiple light points with similar white diodes the difference between the multiple diodes is small at any given point in space and time. (mix well)
When mixing say red and blue diodes, the difference is far greater and the harmonics are sparse and well separated across the band leaving dead spots. (fewer harmonics with spaces in between)

http://en.wikipedia.org/wiki/Young's_interference_experiment

What would the output look like in Young's experiment with red and blue diodes vs. white ones?
What happens to the light as it hits the plant and travels through the canopy?

 

[rives]

Has anyone actually seen real negative effects by using the 660's or any other specific spectrum? On RIU do they have documentation on the negatives? That would be worth researching a bit.

No, in fact the reverse is true - many of us are successfully using 660's. I haven't been following the argument on RIU lately, but from what I saw the opposition was theoretical, and based on mj being a "c3" plant. I think that PetFlora is the only one with a bad experience with them, and he was using HO T5 lamps, not leds. I'm not sure why he considered them a 660 source - any fluorescent lamp that I've seen has a pretty wide spectrum and the visible portion of it is just tweaked around a bit with the phosphors to change the way that humans perceive it. Perhaps he can jump in and explain.

 

[tenthirty]

Please correct me if I'm wrong,

But in simplistic terms, red makes stretch and blue makes short and squat.

I also don't like the fact that there is a big red spike in the spectrum, and that from a separate point in space (angle of incidence) doesn't help either. (Young experiment)

There is a possibility/probability that as the light travels through the canopy, there will be spots on the plant that are receiving all or mostly the red light from the 660nm leds.

It is my understanding that stretch is caused by the r/fr ratio as the light travels down the plant.

 

[rives]

I think that the tendency for the plant to stretch under red light is largely dependent on the stage of the plants development. It the red light is introduced too early, it is interpreted as being weaker and the plant stretches to get closer to it. After the plant is 2-3 weeks into the flowering process, the tendency to stretch goes away, the red light is interpreted as being the onset of autumn and the plant accelerates the flowering process in order to insure the continuation of the species. Equally simplistic perhaps, but that kind of encapsulates my understanding of the process.