Introducing - specializing in DIY and Citizen COBs

Discussion in 'LED and other Lighting' started by CobKits, Aug 2, 2016.


    CobKits Well-Known Member Rollitup Advertiser

    was planning on replacing 1818 with cxm22 but peopel keep asking for them so i jsut put anorder in for them in 3000/3500k and 80/90

    ~4 weeks
    Humanrob likes this.

    nfhiggs Well-Known Member

    I call bullshit. Your numbers do not add up. If the parallel voltage applied was higher than both Vf's of your 600mA individual tests, then BOTH would have pulled more than 600 mA at 34.9V. You are either lying or incompetent.

    Humanrob Well-Known Member

    I'm adding to an existing build, so I was just continuing with what I used before. But in this case each pair is on a separate driver, so I suppose I could switch over. It's nice that they use the same heatsinks and holders.

    Humanrob Well-Known Member

    Got the graph paper out and I'm mapping out the layout. For this iteration I'll have 6 cobs in a 3x3 tent. What is the optimal distance apart for 75w cobs?

    CobKits Well-Known Member Rollitup Advertiser

    6x75 in a 3x3 is a fair amount of light, i imagine you'll be dimming a bit.

    easy way to map it is to take your 36" and divide it by number of cobs and go half that spacing from each wall on both ends

    so if your 6 cobs are in a 2x3 grid, in the 3 cob direction it would be 36/3= 12 or in other words from the wall cob#1 is at 6", cob 2 at 18" cob 3 at 30"

    in the 2 cob direction they are 18" apart and 9" from the wall

    in practice (esp in bigger tents) to keep frame size down you can cheat toward the middle a little. esp if hanging your fixture high
    pop22 and Humanrob like this.

    Humanrob Well-Known Member

    My end game is 9 cobs running at between 40-50w each in a perfect 1 sq/ft per cob pattern. Could happen next year.

    Thanks for those guidelines! When it comes time to actually build it, I'll probably do something like that. But I got stoned and started thinking...

    All I could find was really small graph paper... but that didn't stop me (it only slowed me down). I started playing with distances, trying to figure out the most even light spread configuration. My first locations had too much overlap, so I moved them apart a bit and redrew my imagined per-light coverage radius with a colored pencil. The top left and bottom left are 16" apart (on center), the bottom middle one is about 12" from the left and right bottom ones.

    This layout does leave a weak spot in the middle, and would come with some building challenges (!!!), but it was fun to think about. When I'm faced with the actual measuring and cutting, I'm sure I'll reread your response. :)


    Dave455 Well-Known Member

    Be nice to see PAR map on light layout. Believe you will find photon overlap in center will
    be high enough to avoid added COB..
    Humanrob and CobKits like this.

    SSGrower Well-Known Member

    Found out some good info I think with regard to safety. First off its pretty cheap even though it may be overkill. Also I may have misinterpreted some of the electrical code (I'm talking about NEC class 1 wiring methodology). My boiler uses awm rated wire 600v (one component relay with 1000v) I think for two reasons temp and ampacity requirements and in a particularly thin gauge of wire 16 or 18. Most of us use 18 in our builds, this awm rated wire runs about 40 bucks for 500 ft in 18g, i could only find it at a wire distributor.
    I will be rebuilding the led side of my lights with this wire as I only used about 150 ft of it to relocate my boiler power vent and hopefully make buildung inspector boy happy so we can move on with the rest of the remodel project.

    Anyway, Thoughts on awm rated wire?

    CobKits Well-Known Member Rollitup Advertiser

    link it
    pop22 likes this.

    pop22 Well-Known Member

    AWM wire styles are selected by end-product manufacturers based on their specific voltage and temperature
    ratings, mechanical abuse, environmental exposure, flame ratings, etc. AWM has not been evaluated for general
    wiring applications in accordance with the NEC." which means it is also not UL listed. I'd get rated wire just for safety purposes

    Here is more than you ever wanted to know about wire! Good info


    CobKits Well-Known Member Rollitup Advertiser

    happy customer

    Attached Files:


    SSGrower Well-Known Member

    Your right more info than i ever wanted!

    But UL does test awm wire

    And as you state its use is dependent on environmental conditions. For an appliane to be ul certified its wiring must pass whatever testing ul dictates for that appliance or class of appliances. The wire that I am speaking of has higher ratings (105 deg C, 600v) than any wire availble through typical means avilable to the general consumer. It also meets other standards (MTU) but the temp rating was I was after. There are far more strands translating to lower resistance and less heating, and it has a tangible "feel" of quality when handled. What type of wire would be better?
    pop22 likes this.

    SSGrower Well-Known Member

    Cant really link a weeks worth of research and chasing rabbits down holes, NEC chapter 3? Table 402.5 (curent limits for gauge size) mostly my objective was to maintain the same rating of wire that was in the boiler out to the blower vent location, since it followed the bvent flue exhaust that reqired certain clearnces from combustable materials, so that meant conduit was requred in addition to a high temp rating on the wire.
    pop22 likes this.

    pop22 Well-Known Member

    Ahh its stranded? interesting! And thanks for the info! So this is available to contractors only? Or only available in large spools?


    SSGrower Well-Known Member

    Can't get at home depot and the like, even QED electrical supply did not have but they sent me to a place called All Cable, they normally have a50 dollar minimum purchase but dude was nice and helped me out.
    pop22 likes this.

    HEEVES New Member

    Still reading all this but just wanted to say thank you! Amazing thread!
    pop22 likes this.

    pop22 Well-Known Member

    Sorry, wrong thread

    Cedru Member

    @CobKits what are your recommendations for a 5' x 5' x 6.5' FLOWER ONLY tent?

    I already have most of my veg tent complete, placed the next to last order today - so now it's time to prepare for flowering in 2 months.

    Quantum boards or COBs? How many of each and which driver(s)?

    Thanks in advance,
    *.*.* Cedru *.*.*
    dabby duck

    dabby duck Well-Known Member

    wow, no I know the stigma of the LED thread?

    is inexperience incompentence, I hesitate to ask questions if thats the answer.....
    [im sorry, I am new and dumb, but the vile just rolled of the screen with that post......]

    would you happen to carry Adjustable Ratchet hangers for a DIY light? I am in need of at least 4, or maybe 3 sets of 4?
    Please let me know at your convenience and IM is okay too if you prefer, Really Awesome Thank Youuuuu!

    :joint: :joint:
    pop22 likes this.

    CobKits Well-Known Member Rollitup Advertiser

    I dont, but i should!

    try amazon/ebay
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