Changes at Timber Grow Lights

Or_Gro

Or_Gro

Well-Known Member
Stephenj37826 said:
Once we have everything up and running we will get real creative. :)
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How about qb18,35 with independent/dual fr control for both emerson and initiator effects? Separate from other boards. With more rugged power socket.

Killer supplemental!

I’m with you guys on boards & kits, great stuff. You know my general feelings about fixtures.
 
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dannykay

dannykay

Well-Known Member
Humple said:
Yes, I've seen the 120 on YouTube, but unfortunately not in any configuration approaching the light-ceiling, and not in any space sized appropriate to its power (unless, as you pointed out, it's being used for veg only).
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I'm using 6*qb120 along with cobs in my 8*4 flowering tent. Can't complain at all, their doing great.

The no heatsink option for these 120 boards (or the Samsung/bridgelux strips for that matter) is a huge advantage for cutting down overall costs including shipping. I know most of yoy guys here are US based, int' shipping charges are a bitch, w/o heatsinks you can really cut down shipping as well.

In any case, good luck going forward @RainDan, great portfolio so far. Keep it up!
 
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Yodaweed

Yodaweed

Well-Known Member
wietefras said:
They grow plants you mean? The point is that they are overpriced and offer poor light uniformity at low distances. ie you need to hang them way too high which causes loss of light on the walls. Up to 50% of the light can be lost in a 2'x2' tent with a single QB at 18". As demonstrated by ledgardners PPFD measurements of such a setup.

Now change that one board to 4 spread out COBs and you can half that hanging height and therefore cut in half the wall losses. Or go for led strips and cut down on hanging height and wall losses even more.

So that "better spread" that he is talking about can really have a big impact on performance.

They cost a lot less than QB's? Not sure how that is a downside though.
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COBs have massive hot spots directly under them. That's the downside to COBs, great output directly under them.
 
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wietefras

wietefras

Well-Known Member
Yodaweed said:
COBs have massive hot spots directly under them. That's the downside to COBs, great output directly under them.
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No they don't. Don't you get tired of making stuff up?

I know you are just trolling, but let me explain for people who are actually interested in facts. The bigger the light source, the bigger the "hot spot". That's "hot spot" in the sense of a slightly brighter area and not a real hot spot where the light is really too bright, because if you get an actual hot spot then your light is simply too low.

So then for instance a 1000W HPS will have a huge center region that's more brightly lit. A 315 CMH brighter center region will be smaller, but still quite large. A 100W board or 100W COB have a similar uniformity and therefore similar sized brighter area in the center.

Now COBs are usually powered much lower than that and a 50W COB (like a Cree CXB3590) has better uniformity than a 100W board or COB and COBs at 25W are even better still (Citizen 1212).

So even just saying "COB" doesn't mean much when you can run them from 200W to say 10W.

If you have an actual hot spot with COBs (or any type of light for that matter), then you are way to close. Which would mean less than 2/3 of the distance between the rows of COBs. Anmd even then it's not bad or anything. Just a bit brighter in the center. I have my COBs a few cm/inch away from the highest tops and they are even fine with that.

Still you go for optimal uniformity and that means darkest areas still have at least 80% of the average light intensity.

Relative uniformity map for 1 COB @ 45cm (18") in a 2'x2':
1 COB @45cm.png

Same for a QB:
QB @45cm.png

The uniformity for the QB is ever so marginally better. Either way it's clearly preposterous to claim that a COB has a "massive hot spot".

Now where the real difference comes when you run the COBs at a lower wattage. For instance 4 COBs in the same space can be lowered to 20cm (8") instead of 45cm (18"):
2x2 COB @20cm.png

Same uniformity as with the single COB and single QB before, but you lose much less light on the walls. About 47% more light on the plants from the same watts and PPF due to lower wall losses.

Also for a small tent this lower height is much more convenient since small tents will be lower too. Less need to scrog if you gain 25cm (12") in unused height from being able to lower the fixture. With led strips you could go even lower. With 4 led strips in the same space you could go down to 3" to 4" for the same uniformity.

Now try the same with a QB @20cm:
QB @20cm.png

You get one "massive hot spot" directly beneath the board and therefore it's completely unusable at that height. So with a single QB you are stuck at that 18" and wasting a lot of light on the walls.

If you think I'm exaggerating, take a look at ledgarners measurements of the QB288 v1 vs v2. His numbers are even worse for the QB's. Probably because his tent walls are less reflective (I wonder if he uses a tent at all frankly). He gets only a peak value of 730umol/s/m2 in the center below the QB. From a light which according to the specs should give you an average of close to 1000umol over that 2'x2' at 140W. Instead the actual average is something like 550 to 600umol/s/m2 on the plants.
 
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Belko

Belko

Well-Known Member
wietefras said:
No they don't. Don't you get tired of making stuff up?

I know you are just trolling, but let me explain for people who are actually interested in facts. The bigger the light source, the bigger the "hot spot". That's "hot spot" in the sense of a slightly brighter area and not a real hot spot where the light is really too bright, because if you get an actual hot spot then your light is simply too low.

So then for instance a 1000W HPS will have a huge center region that's more brightly lit. A 315 CMH brighter center region will be smaller, but still quite large. A 100W board or 100W COB have a similar uniformity and therefore similar sized brighter area in the center.

Now COBs are usually powered much lower than that and a 50W COB (like a Cree CXB3590) has better uniformity than a 100W board or COB and COBs at 25W are even better still (Citizen 1212).

So even just saying "COB" doesn't mean much when you can run them from 200W to say 10W.

If you have an actual hot spot with COBs (or any type of light for that matter), then you are way to close. Which would mean less than 2/3 of the distance between the rows of COBs. Anmd even then it's not bad or anything. Just a bit brighter in the center. I have my COBs a few cm/inch away from the highest tops and they are even fine with that.

Still you go for optimal uniformity and that means darkest areas still have at least 80% of the average light intensity.

Relative uniformity map for 1 COB @ 45cm (18") in a 2'x2':
View attachment 4203232

Same for a QB:
View attachment 4203233

The uniformity for the QB is ever so marginally better. Either way it's clearly preposterous to claim that a COB has a "massive hot spot".

Now where the real difference comes when you run the COBs at a lower wattage. For instance 4 COBs in the same space can be lowered to 20cm (8") instead of 45cm (18"):
View attachment 4203234

Same uniformity as with the single COB and single QB before, but you lose much less light on the walls. About 47% more light on the plants from the same watts and PPF due to lower wall losses.

Also for a small tent this lower height is much more convenient since small tents will be lower too. Less need to scrog if you gain 25cm (12") in unused height from being able to lower the fixture. With led strips you could go even lower. With 4 led strips in the same space you could go down to 3" to 4" for the same uniformity.

Now try the same with a QB @20cm:
View attachment 4203235

You get one "massive hot spot" directly beneath the board and therefore it's completely unusable at that height. So with a single QB you are stuck at that 18" and wasting a lot of light on the walls.

If you think I'm exaggerating, take a look at ledgarners measurements of the QB288 v1 vs v2. His numbers are even worse for the QB's. Probably because his tent walls are less reflective (I wonder if he uses a tent at all frankly). He gets only a peak value of 730umol/s/m2 in the center below the QB. From a light which according to the specs should give you an average of close to 1000umol over that 2'x2' at 140W. Instead the actual average is something like 550 to 600umol/s/m2 on the plants.
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I’m actually building a fram
with four ZEUS XT (29,5x44,5cm/308lm301b) for a 4x4 space orca tent, I thought to operate the boards 10cm from walls, let 40cm space in the middle to balance the distribution.
As I understand it, by doing this I'm just going to lose light on the walls? so it is better to run them at a regular space?

Thank you
 
diyled

diyled

Well-Known Member
Belko said:
I’m actually building a fram
with four ZEUS XT (29,5x44,5cm/308lm301b) for a 4x4 space orca tent, I thought to operate the boards 10cm from walls, let 40cm space in the middle to balance the distribution.
As I understand it, by doing this I'm just going to lose light on the walls? so it is better to run them at a regular space?

Thank you
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You want to get each board spread out so its central to each 2ftx2ft section. Not to close to the walls.
 
Belko

Belko

Well-Known Member
diyled said:
You want to get each board spread out so its central to each 2ftx2ft section. Not to close to the walls.
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thank you very much you help me a lot, I really do not want to disassemble the frame once in place, it would be a mess^^
I will change my setting, I ordered a luxmeter but I will not receive it for a few weeks.
 
Or_Gro

Or_Gro

Well-Known Member
Two 48sams in a 4x4, measured every 6” vertically and horizontaly, 3 dimmer settings (full, med, lowest) multiply values by 1000 to get ppfd.

907560C4-F933-4908-A402-4A35F428680F.jpeg

AD65A4F8-357A-4D53-B59B-B9297540932E.jpeg

E7728BC7-C7D1-4761-A0FB-ACD0A5B00F85.jpeg

29708B3E-16A9-4870-933E-3A931814D66B.jpeg

6D9FBE91-C1F1-4CD4-99D9-4345142347E9.jpeg

Adjust dimmer to get ~1000ppfd across the board, 18” to 48” above cola tips. Mapping details in post mentioned earlier.

Dan knows his stuff, qbs and cobs, both do the job well! Buy Timber, support a great price/perfornance fixture maker.
 
wietefras

wietefras

Well-Known Member
When you put 8 boards in a 4'x4' then there is no need to hang them at the same height as 1 board per 2'x2' (18"). 12" or perhaps even 10" should be fine. That would save a lot in wall losses again.

1000W of led in a 4'x4' is massive overkill too of course, but indeed you can dim it down to a more practical level.

Still, the point was, Dan can make a fixture that works just as well (better really) with COBs instead of boards.
 
Or_Gro

Or_Gro

Well-Known Member
wietefras said:
When you put 8 boards in a 4'x4' then there is no need to hang them at the same height as 1 board per 2'x2' (18"). 12" or perhaps even 10" should be fine. That would save a lot in wall losses again.

1000W of led in a 4'x4' is massive overkill too of course, but indeed you can dim it down to a more practical level.

Still, the point was, Dan can make a fixture that works just as well (better really) with COBs instead of boards.
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Massive overkill? Wha? Even 40-65dli, w/ elect efficiency, running 1500 parts co2, low 80sF - its called optimum photosynthesis!

No, point is dan knows his shit, qb and cobs! And delivered the absolute best price/performance on these fixtures.
 
Or_Gro

Or_Gro

Well-Known Member
gwheels said:
I like having more than 1 light for when the plants decide to grow differently in height. I am currently using 3 lights in my 4 x 4 (2VL a QB135 and 238 watts of quantum strip) all at various heights. It is pretty nice.
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Exactly: multiple lights or raise plants to same height or manage multiple dimmers, or have separate lights or train them differently...lots of possible solutions to multiple plants at diff hts. I do em all depending on situation.
 
Or_Gro

Or_Gro

Well-Known Member
gwheels said:
I guess the moral of the story is do not run sour diesel with critical mass :D or have lights that have different heights.
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Or use your brain to figure out another effective solution.

I’m using pedestals in current grow so i can have qbs, emerson, initiator, and uva-b at ht where uv doesn't damage diff ht plants and the other equip.
 
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