COB spectral research microcab

Staxxx said:

They look great, this should be fun to watch. I have a similar pre-drilled heatsink from RapidLED. I wanted to build a 3070, but I really want to avoid drilling/tapping. Does the ideal holder screw right in to the existing holes on the heatsink? What kind of screws did you use to mount the cob? Seems like the screw holes on the heatsink are smaller than the m3 size recommended for the holder. Thanks in advance.

Click to expand...

Used a 4-40 pan head screw and washer. There's a picture in the first posts of thread. Almost perfect for both the 3070 and 3590 ideal holder. I say almost because it just barely makes it with a little finesse. A Dremel or file could take away a tiny bit of material in the screw keyhole to make it perfect.

churchhaze said:

Does anyone else use a small nail as a makeshift center-punch before drilling into aluminum?

Click to expand...

No..sounds like it'd work in a pinch though. Easiest way I find is a 3 step process.

Use a center punch set to hardest punch. Punch it a few times...each time goes a little deeper.

Small bit to start the hole will wander less sitting better in the punch mark..

Final bit to desired size.

Positivity said:

Used a 4-40 pan head screw and washer. There's a picture in the first posts of thread. Almost perfect for both the 3070 and 3590 ideal holder. I say almost because it just barely makes it with a little finesse. A Dremel or file could take away a tiny bit of material in the screw keyhole to make it perfect.

Click to expand...

Cheers, thanks for the info man, much appreciated!

@Positivity

I just received my 3 far-red LZ4-40R308-0000 and APC-25-700 current supply for driving the 3 in series.

http://www.mouser.com/Search/ProductDetail.aspx?R=LZ4-40R308-0000virtualkey62410000virtualkey897-LZ440R3080000

http://www.mouser.com/ProductDetail/Mean-Well/APC-25-700/?qs=/ha2pyFadujgXeWlf0w%2bdD19SkOgTMF80g48ZCr29pgyQeF%2bqq8ZIQ==

How do you go about pulsing them for 15 minutes? Do you have a separate programmable timer and just hope they synchronize, or do you have something fancy for this? (like some sort of trigger for a pulse)

Anybody else have a way they like to do this?

Second, what do you do for a heatsink? Do you just have a long aluminum flat bar, or is there a sink? I was thinking either that or 3 chipset heatsinks so i can arrange them however I want.

It might seem like overkill, but what about the 2.079" profile from heatsink USA? It's about 8 dollars for a 2 foot sink. I could get 2"x2" sinks for 70 cents each. I wonder if he'd have a problem with that, because that seems like it would be fine.

http://www.heatsinkusa.com/2-079-wide-extruded-aluminum-heatsink/

Also, you have a lot of useful info and pictures in your threads. You should really consider changing your signature to include links to each of your threads so people can track them down easier!

Thanks!

churchhaze said:

Anybody else have a way they like to do this?

Second, what do you do for a heatsink? Do you just have a long aluminum flat bar, or is there a sink? I was thinking either that or 3 chipset heatsinks so i can arrange them however I want.

Click to expand...

i have my whites (and UVA) on one circuit. (own timer)
I have my 645-660nm's on another circuit (own timer)
and i have my 730nm's on another circuit (own timer)

Pretty basic...but it worx...

On my older setup i used 40mm (wide) x 300mm (long) x 12mm (high) bars running 5 x 5w multis @ 700ma ..... passively cooled...barely noticed any temp change...

churchhaze said:

@Positivity

I just received my 3 far-red LZ4-40R308-0000 and APC-25-700 current supply for driving the 3 in series.

http://www.mouser.com/Search/ProductDetail.aspx?R=LZ4-40R308-0000virtualkey62410000virtualkey897-LZ440R3080000

http://www.mouser.com/ProductDetail/Mean-Well/APC-25-700/?qs=/ha2pyFadujgXeWlf0w%2bdD19SkOgTMF80g48ZCr29pgyQeF%2bqq8ZIQ==

How do you go about pulsing them for 15 minutes? Do you have a separate programmable timer and just hope they synchronize, or do you have something fancy for this? (like some sort of trigger for a pulse)

Anybody else have a way they like to do this?

Second, what do you do for a heatsink? Do you just have a long aluminum flat bar, or is there a sink? I was thinking either that or 3 chipset heatsinks so i can arrange them however I want.

It might seem like overkill, but what about the 2.079" profile from heatsink USA? It's about 8 dollars for a 2 foot sink. I could get 2"x2" sinks for 70 cents each. I wonder if he'd have a problem with that, because that seems like it would be fine.

http://www.heatsinkusa.com/2-079-wide-extruded-aluminum-heatsink/

Click to expand...

Im using the 2.079" profile 24" long per 9 LED stars for my R/B string. Shipping was what makes the price go up considerably on them but still not a bad price if you buy multiples, I got 4 24" long for just over $50 with shipping and $5 cutting fee. Nice little heatsinks.

churchhaze said:

Also, you have a lot of useful info and pictures in your threads. You should really consider changing your signature to include links to each of your threads so people can track them down easier!

Thanks!

Click to expand...

Will do..good idea. All this stuffs building up. Guess I'm more full of it than I thought..haha..


I just use a seperate timer. The hydrofarm ones are nice so far. Dual outlets and reliable. The new version brinks have failed a few times already.

I'm down to six minutes (3 min before 3 min after)from an initial 10 min. Still seeing the same fast flowering so I'll probably try and drop it even further. Maybe take it down to just two minutes next time. One minute before lights out and one minute after. I had considered running them during lights on after stretch but I really don't think that helps anything at all. Any morphological differences may have been related to density. But after seeing the density of this round without it I see no reason to do that.

Nice leds and driver. That's the way to go, ledengin just reeks of quality looking at their product compared to the rest. You can really see the attention to detail. Mine are minimally cooled and still run like day 1

For heatsink..

Full heatsink would be nice. Kind of a lot of excess metal for the job though.

My flat aluminum strip is super minimal. If you think about it, it's more metal than what's devoted to most leds. The strip can be bent to hit different angles/areas. Really light...etc..

Actually I've been considering aluminum box tubing in the same size length instead. Perfect place to run the wires, it's more rigid, still light, and more metal to cool the led. I actually have those parts ready to go but the strip works so well I haven't bothered.

Small heatsink screwed/epoxy to the strip where the leds go might be nice too..

About 2 weeks into flower

I say "about" because my timer hasn't been working at all. Need to get a new one soon. The on/off times have been manual and all over the place.

I also needed to put my driver on the heatsink and change to a faster fan. Noctua fans may be good for stealth but the fans are sloooow. I could have just vented the room better but this is another approach to heat. With leds..it seems..get to the heat first and you don't need to vent excessively. The driver got hot being on the wood sidewall. Simply placing it on the heatsink and letting it get cooled by the airflow there solved the heat issue. Nice and cool now..

Can't wait to see this 2700k canopy develop..

I know it's not the first time it's been done. But for me this is a great comparison to my more complicated big light. This will decide my future direction in a lot of ways..

Ramble..ramble...ramble...lol. Pic!

Pos ,I think I'm allowed here ,to post my most recent thoughts about leds ....

Who knows ..
'Might be the next project for the wonderful " led micro-cab -min-lab " chamber of yours ...
...

We both know about the abilities of a CXA3070 3000K 80CRI ..
Add a CXA3070 5000K (CRI under question yet ... ) ..
Why ?

Check this " abstract "






First phrase of interest ...

As N-fertilization rate decreased, the
marijuana plants produced leaves with lower chlorophyll
concentrations and higher reflectance values in the visi-
ble wavelength region, particularly at 550 nm.


So ,the more N assimilated ,the less green light is reflected .
Dark green leaves instead of ' lime ' ones ...
Dark green leaves like the vigorous and healthy field grown mj has ...

( If leaves could absorb all the wls from ~300 nm to ~ 800 nm,they would appear black
to humans .The less green is reflected (thus transmitted or absorbed ) ,the leaf appears
as darker green ...The less chloropyll content ,the more the leaves appear yellow or white ...
Higher N assimilation directly related with higher green wls absorption ,is a enough proof ,
that plants actually use green light ...What stops them really from using 100% of the incident green quantas ,is the nature of Magnesium itself ,in ionised state *(/used as a center ion in both chlorophylls A& B )...


Thus the 5000K whites ..
Way more efficient than any green monochromatic led ...

During the vegetative stage ,where N assimilation is at it's peak ..

You want more N to be assimilated ?
You got to provide enough green light ...

If you provide enough green light ,then the rest wls ,have also to increase in power ,
in order to minimise "neighbouring plant avoidance / competion syndrome " ..
(part of shade avoidance ,induced from excess green wls instead of excess FR) ..
Thus overall power should increase ....

Which other monos, have to be used ,in order to increase power ?

That is easy to answer ...

Cannabis differs from other plants ,regarding their spectral signature ,in those wls :

- 670 nm (674-675 nm )
-720 nm
&
-800 nm

...

So ...
One led system ...for the chamber ...

CXA3070 3000K ,channel one - The Basis Core
CXA3070 5000K channel two - Extra Blue & Green power
Deep reds 670-680 nm channel three -Extra Deep Red power
Far reds 720 & 800 nm channel four -Extra FR power


In other words as mj 'ages' it transmits less FR (720 & 800 nm ) through it's leaves ...
It also reflects less FR ,proceeding into flowering ...
That means that actually those wls are being used !
Not while at vegetative growth early stages of mj ,neither while on the early
"transition to reproduction' stage ...
It will cause severe shade avoidance syndrome ...
(stretching ,sparse branching ,etc )

While in later stages of mid to end of flowering ,
FR can't cause SAS ,thus plants will not strecth ...

On the contrary ,those wls are being used ...'
So they are needed ...
Leaves are getting old and the production of new ones has ceased..
Old leaves are not able to efficient utilise certain wls as they used to ..
They tend to photosynthesise using more and more of FR wls ...

So ,might this be the holy grail of big fat dense buds ?

Might be ..
But for sure not by itself ..
Ain't enough ...

All the rest ,have to be done accordingly ,for the plant reaching constantly ,
it's genetic potential in certain aspects ...
By light manipulation of course ...

Green & blue when needed ,for healthy "childhood" ...
(later on -during flowering- to 'back off ' a bit, in power terms ... )
Deep reds ,gradually increasing ....
And FR for the 'end' ( my only friend the endddd...) ,as the 'final boost ' ?

................................

And a tad of UV ,maybe ...

Cheers.

Check this out ...
What happens in Colombian field-grown cannabis leaf 'attitude' ...
Check the changes (some are pretty ..radical ) it undergoes ...

A ) Green wls ....

Reflectance: Difference is positive as leaves age...
More and more green light is reflected back ...( 10%,5 Jul >>> 12+ % , at 22 Sept ...
Transmitance : From ~ 10% of transmitted green photons at 5 July it drops to 8% , at 22 Sept ...

B ) Check deep red ...
C ) Check FR .....

-1,7% reflected back at 22 sept ,and -4% is transmitted ..

They are indeed 'subtle' power changes ...
But maybe they do make all the 'difference ' ....

What about a 3590 5000k?



Interesting info...going to have to let it sink in a bit. The reflectance charts tell quite a story...not sure how that can translate though. Cmh hits farther into the ir zone dosent it? Going to need to look at sun charts and cmh charts to see what's going on there. Something leds are missing out on right now?

Still can't believe how fat the 3k is making the herb this time around...it's quite close to optimal as is. But...monos will be perfect to help dial in what's not there.

Complicated light schedules. But will it be more important than amount of light. 1000w hps puts out how many lumens?? 120000 or something...how many white led grows do that...not many. The ones that do are probably seeing as good a result and as fat a cola as the big hids regardless of ir levels

So SDS, you're saying to incorporate NW's into mid flower?

I worded that a bit wrong above. I do think the far red and ir levels matter. Seems to be what separates the cmh from an hps where it matters, on the right side of the spectral graph away from the blues.

Philips elite agro 315w cmh..



Hortilux super hps


Hid hut hps




The cmh does seem to be the best performing spectrum among hid. Although the double ended bulbs have showed incredibly impressive plant structure. Is that an example of intensity trumping spectrum?

I say cmh a lot lately...probably because it mimics the sun with a high cri the best so far. And the results of that are quite nice. Leds would be well off to use that as a spectrum guideline I think.

Green boost is definitely a worthy thought. Green/yellow is what I was thinking...the spectral shift to the left of the chart increasing cri. But then is it worth complicating the led setup using two different whites. Not sure on that...I don't think so..which is why I didn't do another 5k 3k split. Fuller flowers in the end I think..so far..

Regardless, manipulating spectrums are fun. A bit like playing an instrument or any skill. The more you play hands on, the better feel and understanding you get.

Scotch089 said:

So SDS, you're saying to incorporate NW's into mid flower?

Click to expand...

No.

NWs should be used from start (either clone or seed ) at high power,
gradually decreasing to null ,after the first two weeks of 12/12 ...

WW 3000K is the basis ,and should be on ,from start to harvest ...
Increase - @ mid flowering ,peak in power- decrease

Deep reds ,should be gradually increase in power from the start ,
to peak during mid flowering and then gradually decrease afterwards ...
(could be in same channel as WW ? )

Far reds take over ,as their power should be increasing from mid flower ,peaking about harvest time ....

That is probably the closest "long term light quality alteration scheme " ,maching mj seasonal spectral
absorptance under natural sunlight ,using 4-5 different types of LEDs ...
( 3000K - 5000K -675 nm -720 nm -800 nm)


Only "compressed" to 'fit' the average of ~3 months duration ,of a indoor grow cycle ....

Cheers.

Gavita double ended spectrum. Not as broad as I thought. Makes the cxa 3070 spectrum look really good if you ask me. If only the 2700k was as efficient as the 3000k....maybe even a lower kelvin in the future. That would make some interesting color mixing...just mix whites

Positivity said:

View attachment 3236164
... Makes the cxa 3070 spectrum look really good if you ask me. If only the 2700k was as efficient as the 3000k....maybe even a lower kelvin in the future. That would make some interesting color mixing...just mix whites

View attachment 3236165

Click to expand...

This is why I went with the 2700K 3590, and the 3000K and 5000K 3070's for my little tent. I figure that the efficiency loss is minor compared to the overall gains of using LEDs in the first place. Don't get me wrong, I admire you guys for trying to maximize the efficiency, but for me right now, those are just tiny gains on a huge baseline improvement.

Mini cab is doing well. May have to put the light on the exterior of cab for a few more inches...hopefully not..I like everything contained.

Bubba clone on the left and peyote purple on the right. Peyote is showing better node spacing, hopefully she's a keeper.

I was just about to reply with the exact same thing!! This is why I went with 3000k vero over 3500k or 4000k, which was suggested. The spectrum is very close to HPS.

mc130p said:

This is why I went with the 2700K 3590, and the 3000K and 5000K 3070's for my little tent. I figure that the efficiency loss is minor compared to the overall gains of using LEDs in the first place. Don't get me wrong, I admire you guys for trying to maximize the efficiency, but for me right now, those are just tiny gains on a huge baseline improvement.

Click to expand...

I've been saying for a long time ~ 40% of WW should be on separate circuit, to be engaged once buds set (~ 2 weeks from pistils)

I wanted 2/6 bars on the BML to be 2700k, and have separate o/o switches, but that wasn't in the cards

Microcab will need some adjustments..

3590 doesn't send out as much light off to the sides as I thought. Has to be placed a bit higher to be used as a standalone source. So I'll probably have to switch this to two 3070 on ends of the sink. 2700k experiment is on hold...may put them on my big light once for fun.

The environment in there is pretty whacked. Uneven lighting, small pots, little air exchange. Can't really make any conclusions on 2700k and flower quality. Smell is down, size is down...taking on what I consider hay. Making good plants look bad. Exactly what I don't want when running through f2s looking for special gals.

So next spectrum...hmmm

4k 3070...with 450, 470, 660 and 670nm. May have to try that if I can fit it on a driver.

Bleached and burned a bit. Too bad the space isn't a bit bigger