I’m beginning to think outside the box while looking into it. Could just be those cookies again…anyway i had a brain fart and found an obvious solution. Build a box and plaster the inside with these https://www.ledhut.co.uk/led-strip-waterproof-ip67-60-large-high-power-chips-per-metre-5-metre-roll.html 
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They are inefficent with 20-35% of the wattage being burned off by the resistors in those lights. They work though just like any light but just not efficient.
I know i was joking but only partially because i could see these lining a veg/clone box. They can be cut to length and a couple of those strips would cover the insides of a small box nicely.
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No they would fully work and work decent if you have enough light lots of people use them in the space bucket world, its just they are pretty inefficient.
I used some for this quick “Mini” 1 gallon grow project i had fun doing.
For small and “cheap” cobs i’ve been recently using the chips and ballast from standard off the shelf Screw in Led bulbs. They are decently efficient at around 110-130lm a watt range but ultimately only cost around $2-4 a piece minus any heat sink your gonna need throw them on.
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Not been much action on the affordable cob build and my other desired project is a solstick build but the 10 sticks needed wont be cheap so in the mean time i’m having a go at building a cob bar for the missis. I ordered a 146 x 22 x 1000mm heatsink bar, 5 Citizen 58w 2700K CLU38 & holders from ebay (export-estonia) and thermal pads but need suggestions for a suitable, dimmable driver and connections. I take it series connection and constant current but what driver is best for around 180 to 200w ? i’d go a bit higher if poss but not much obviously. I will probably want to mount a fan over the top of the bar to help cool the thing too but i need to research a fan and speed control, something dirt cheap from ebay probably. I want to dip my toes in to this diy led fixture building before i throw myself in at the deep end 
Ok looks like i need more chips, another 3 should do to give around 200w with one of these https://www.mouser.co.uk/ProductDetail/MEAN-WELL/HLG-185H-C700A?qs=%2bmCJZPMmHFNeS6l9UeqTUQ==
That’s thanks to @anon58740919 cos i’m going by his build for Gazz
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After discussion with @anon58740919 i’m going with two 1m heatsink bars with 4 cobs each and i will see how close each bar can get to 100w before passive aint enough anymore and i need fans
Just ordered 5 x 4000K CLU38 so i can fit a mix. All i need to order now is another 1m bar, a driver, heatproof wire and junction boxes. Cheap it aint but i’ll spread the cost over a few weeks or so to lessen the pain a bit
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Another 1m heatsink bar ordered today and a new soldering iron. Wire, plugs & junction boxes will be next.
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Been looking at these for a cheap cooling solution if passive aint enough https://www.ebay.co.uk/itm/Arctic-F12-TC-120mm-PC-Case-Cooling-Fan-Temperature-Controlled-Silent-Quiet/161557735867?hash=item259d9769bb:g:bxUAAOSwa39UtDdl
I like the idea of quiet fans that control themselves, might get one at some point to try out.
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Ordered the rest of the stuff including a driver for the 200W cob build today. I’ll post pics when finished if anyone’s interested. A
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Please post pics, we’re interested!
Stay hazed
Jake
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Cheers @Blowingupjake glad someones still interested i tend to plan things to death before spending any money. Then i still overspend anyway 
I looked this every way i could, how to build a decent unit at low cost and it seemed to come back to the sinks cos everything else (cobs, driver etc) is pretty much a fixed expense. Eight individual cob sinks were getting expensive and would still need mounting inside a ladder type frame so more expense and complexity. I also ordered a couple of alloy bar door handles to bolt across the underneath of the sink bars at the ends to protect the cobs and give me something to sit it on while i wire it up etc. https://www.ebay.co.uk/itm/Aluminium-Bar-Kitchen-Cabinet-Door-Handle-Cupboard-Drawer-Bedroom-Furniture-Pull/292028203834?ssPageName=STRK%3AMEBIDX%3AIT&var=591019735755&_trksid=p2060353.m2749.l2649
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Been looking at alternatives for cobs, seems when a particular type gets popular among us growers the price starts to climb. Found these and thought they would do a decent job on a meanwell 700ma driver, what do you think bro @anon58740919 https://www.mouser.co.uk/ProductDetail/Lumileds/L2C5-27901204E0900?qs=%2Fha2pyFaduhXS0jVKSAF0ZiJAbrURVEkJBGTEp5Kmrlx6piYVdGKvdnoukefU3EZ
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For the sake of 35p a chip saving mate I’d go with citilied cluo38 1206’s. Looking at the data sheet they don’t look too bad. Export Estonia for cobs all the way bro
Yes you could run them at 36v 700ma cc too
@Albannach if you have another look you actually lose 12 tiny diodes per chip
The numbers that follow in the case of the chip you referenced run 12 diodes horizontal.
4 vertical. (Think of it like a table)
Cluo38 1206 12 across 6 down
Cluo48 1212 12 across 12 down
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Yeh i keep forgetting to add the vat with mouser lol looks like the version 5 citi chips are running low now but 30 quid delivered for 5x version 6 aint bad eh bro.
I looked at Cluo48 chips, nice output but probably too much for a mainly passive sink rig with multiple cobs like i’m currently building. Individual cpu sinks with fans now that’s a different matter lol
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Not bad at all bro. Even a tenner a chip on the 48s is pretty damn good.
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Sinks and chips turned up today, that was fast! Waiting on a couple new m2.5 drills and m3 taps to arrive and i can start building the thing. I like this sellers name https://www.ebay.co.uk/itm/M5-M6-M8-M10-A2-STAINLESS-STEEL-SCREW-EYES-METRIC-THREAD-OPEN-EYE-NUTS-WASHERS/191825293338?_trkparms=aid%3D111001%26algo%3DREC.SEED%26ao%3D1%26asc%3D20160727114228%26meid%3Dfec349f4466548b9916f7726369671b5%26pid%3D100290%26rk%3D2%26rkt%3D4%26sd%3D222853983217%26itm%3D191825293338&_trksid=p2060778.c100290.m3507
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Got both sinks measured, drilled and tapped for the cob holders today, 16 x M3 holes took a bit of time but i didn’t break a tap or drill bit so quite happy. Next challenge is soldering wires to the chips, might get round to it tomorrow before i get too wrecked
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I must have missed a post or so cos it stopped showing me replies bro. Is it up yet? Show me show me
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It’s alive and i’m actually quite impressed with my own work. Wouldn’t have bothered If it wasn’t for @anon58740919 giving me tips and encouragement. Cheers mate!
I have now replaced her old cooltube/250w hps setup -
With this -
Blackberry and Blue Amnesia xxl
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