DIY price per watt, for top of the line and or best bang for your bucks

lol , the heat sinks in a real mars 2 are the only really good item in the case , the drivers will work
but those are nice sinks in them l will reuse all mine outta 6 mars 2 3 400's 3 900's
I'll save the cases maybe throw some vero cobs in them maybe give to friends

Fastslappy said:

lol , the heat sinks in a real mars 2 are the only really good item in the case , the drivers will work
but those are nice sinks in them l will reuse all mine outta 6 mars 2 3 400's 3 900's
I'll save the cases maybe throw some vero cobs in them maybe give to friends

Click to expand...

Have you ever tried to ascertain the C/W? Just curious, I have never heard anything positive or seen otherwise, to make me think they are of any kind of practical use for multiple cobs.....

what is max dissipation? 120 watts and most are already really hot? That's not a great indictment along with active cooling.

Just playing devil's advocate, mainly because I have not Tj in front of me, but if we could get ANY of Mar's #'s for the below equations that would go a long long way in NOT being antecdotal....

Calculate the thermal resistance [ballpark it even] and then use TR to measure your Max dissipation. I am very curious if max on those heatsinks is even 100 watts for Cree cobs @ 30C Tj... but the math could prove me very wrong too....

Abiqua said:

Have you ever tried to ascertain the C/W? Just curious, I have never heard anything positive or seen otherwise, to make me think they are of any kind of practical use for multiple cobs.....

what is max dissipation? 120 watts and most are already really hot? That's not a great indictment along with active cooling.

Just playing devil's advocate, mainly because I have not Tj in front of me, but if we could get ANY of Mar's #'s for the below equations that would go a long long way in NOT being antecdotal....

Calculate the thermal resistance [ballpark it even] and then use TR to measure your Max dissipation. I am very curious if max on those heatsinks is even 100 watts for Cree cobs @ 30C Tj... but the math could prove me very wrong too....

View attachment 3580327

Click to expand...

I can measure the things if ya want ? No problem there at all u want them done with pix ???
I got some sinks on my thread to show i do pix , love to help out for sure !!

I can't do math head injury , so I'm throwin things together & hope for best if I've done my research here right , I will have cost effective slide into cree cob's from mars fixtures that's the whole point .
limited income forces creative thinking BUT doing math is the left handed monkey wrench in my head aiko

it appears in my models that the heat sinks all the same just in there differently , that's how they keep costs down i'd guess .

Fastslappy said:

I can measure the things if ya want ? No problem there at all u want them done with pix ???
I got some sinks on my thread to show i do pix , love to help out for sure !!

I can't do math head injury , so I'm throwin things together & hope for best if I've done my research here right , I will have cost effective slide into cree cob's from mars fixtures that's the whole point .
limited income forces creative thinking BUT doing math is the left handed monkey wrench in my head aiko

Click to expand...

If you can calculate the Tj or Tc point, I can do the math

But do you have a reliable way of measuring temp?....Laser thermo
gun ain't gunna cut it

Something like this K type thermocouple which will monitor your Tc on the Cob package surface....

Abiqua said:

If you can calculate the Tj or Tc point, I can do the math

But do you have a reliable way of measuring temp?...

Something like this K type thermocouple which will monitor your Tc on the Cob package surface....

Click to expand...

Not Yet ! how much is that puppy & where 'Ya need a pc rigght ?
If I be flyin by seat of my pants as I am , I do need that item
that fit a CXB3590 ? OR do I need a test bed type cob & holder to test sinks ???

Fastslappy said:

Not Yet ! how much is that puppy & where 'Ya need a pc rigght ?
If I be flyin by seat of my pants as I am , I do need that item
that fit a CXB3590 ? OR do I need a test bed type cob & holder to test sinks ???

Click to expand...

This will fit a CXB3590 or 3070 and for that matter every Bridgelux/Cree cob, has a little notch in the bottom corner of the LES, which is at Tc [Temperature to Case] monitoring point for the cob array....then that can be extrapolated to Tj [Temp To Junction] and then all kinds of other goodies
I just fasten my on with Kapton, if you want a permanent mount, the Datasheet usually suggests to dab thermal adhesive to keep it secured....

The easy way is to just use a standalone Sensor..........
http://www.ebay.com/itm/From-USA-Digital-Thermometer-2-K-Type-Temperature-Thermocouple-Sensor-Probe-TOOL-/181777502553?hash=item2a52c89159:g:aQUAAOSwMmBVgjB3




I achieve this a tad differently....I just buy the K thermocouple sensor itself...cheap as hell...
http://www.ebay.com/itm/100cm-1M-Wire-Measuring-Temperature-K-type-Thermocouple-Sensor-Probe-Tester-/400984102527?hash=item5d5c83d67f:g:yYAAAOSwMmBV2sCV


Then I just unscrew the leads and chop to bare wire, to enable me to wire Directly to the Maxx6675 Thermocouple Chip, which has 6 wires going to the Arduino...

http://www.ebay.com/itm/MAX6675-Module-K-Type-Thermocouple-Temperature-Sensor-for-Arduino-R3-NEW-/321569936541?hash=item4adf0fd49d:g:cJ4AAOSwdpxUVKo1


My rig consists of an Arduino Uno R3 Clone.....<$10 US
Max 6675 ThermoCoupleChip <$5
Handful of Sensors $5


The Arduino is probably easiest with a PC, but you DON"T need one, a nice little 16x2 LCD screen with buttons will work too!

I use a little program called RealTerm [CoolTerm also works, not quite as functional] that is essentially a serial port monitor....This enables me to Datalog in realtime if I want....But I usually just take readings and Import them into OpenOffice, for visualization.....

I am working on a Making this standalone with a small Bluetooth receiver...I will control and monitor it all from a bluetooth connection....Been hacking that for a few weeks, but still a lil' wonky

Good luck, PM me if you want to go further down the rabbit hole

Hey @GreenSanta

didn't mean to poo all over your thread...I just see a reply and gets to typin' away

Imho...you should consider the CXB3070 3.5K BB...or maybe even the Vero 29's?

The BB is for the bins, as mentioned above, basically just increased effiency and overall output in order of magnitudes as go from lower bins to higher bins....I believe BB is top bin right now for top Effic and output for a 3500k spectrum from Cree...and basically the same pricing as lower and older bins....

I believe you could find a heatsink length from HeatsinkUSA.com that jives with the your fixtures dimensions..i.e. the individual dimension of each cluster x16, from that 1st light you described...Maybe you can run an 6" piece for example for 1x cob...that will fit into your housing and the fan will blow on it [don't know your exact dimensions, but hopefully you get the idea...]

Right, so if you don't know, Volts x Amps = Wattage....

Take the wattage you need for each cob [for example 1x CXB 3070.....@700ma =24.xx watts @1050 =38.xx watt @1400= 52.xx]

I use Supra method taught to me to measure how many watts a piece of Heatsink from HeatsinkUSA would be able to cool both Passively and Actively....

Under each specific length of profile is Surface AreaCm^2....... this is per inch of that type of profile....For instance... the 5.88" profile is probably the most popular around here...in the thumbnail...it says 260.01 cm^2.....The other quick guidelines are::::40cm^2 = 1 watt ACTIVE cooling.....or 110 cm^2 = 1 watt PASSIVE cooling.....

So 1" length of 5.88" wide heatsinking would be good for about 260/40 = 6.5 watts cooling Active
260/110 = 2.4 watts of cooling Passive....

Maybe you need a 6" inch piece for each of the 16x clusters....Actively cooled, each 6" long/5.88" wide heatsink would be good for 39 watts or so...Just for example....Hope that Helps....

Abiqua said:

Good luck, PM me if you want to go further down the rabbit hole

Click to expand...

rabbit hole be dammned Yeah !
pm ya later today , i've got an extra ho'built PC that's not doing anything just loaded win10

Ok pix brand new mars 900 about 5 weeks ran last spring I used it 12/12
below the pix is my thread with more pix this is not my thread but greenstana's
soo Thhx GS
https://www.rollitup.org/t/slappys-perpetual-led-hack-discussion.894986/page-2#post-12215854

that's a way that's easy on my brain / hand rite & then a pix

those are 68 cm long in the 900 I'll measure the 400's but the profile is the same I remember that when I cleaned them 2 weeks ago ( my place is dusty , ranches near by )
looks like the fans are wired at the end of the driver chain ? I leave all wires attached & strip the harness with all driver / fans attached then place on a white sheet then pix & u circirt guys can figure that out I
l'l stretch the wires out & we'll get a exploded view

@Fastslappy you can post all you want this not ''my'' thread its everyones thread lol. my questions were mostly answered, so im happy. I am still a bit worried about the price for DIY, after converting to canadian dollars I think I might have to wait a bit. or maybe I ll order 5 cobs, the appropriate drivers and just start messin around with them. Now I know which cobs I want and I can easily find the appropriate drivers for them.

some guys get sensitive about their thread & I want to be polite
I am gonna cut & paste some of these posts of mine on my thread
hopefully i helped

If I get this right,

I could order 4 of these: (heatsink+fan??) one COB per unit
http://www.newegg.ca/Product/Product.aspx?Item=N82E16835186070&cm_re=alpine_11-_-35-186-070-_-Product

4 COBS CXB3590 3500k CD
http://kingbriteled.en.alibaba.com/product/60259719620-801574224/CREE_CXB3590_3500K_CD_CXB3590_0000_000R0HCD35G.html

1 driver Meanwell HLG series
http://kingbriteled.en.alibaba.com/product/60401906442-801515460/Meanwell_HLG_185H_C_Series_1400mA_200W_LED_Power_Supply_HLG_185H_C1400_HLG_185H_C1400A_HLG_185H_C1400B.html

maybe 4 cob holders, and what else^? this would be a 200 watts 4 COBs fixture

Does this make any sense^?

lol I am rewatching growhack from growmau5 and basically answer all of my questions, sorry for my laziness... fkin stoner