DarthBlazeAnthony
Well-Known Member
Perhaps we could do a build simultaneously. What % of the parts do you have so far? What footprint do you need to cover? 500-600 watts is my goal to cover a 4x4 tent.
COB holders - the basics
- Thread starter Mellodrama
- Start date
GroErr
Well-Known Member
Will try and get some time to post up the list, waiting for a couple of heat sinks and drivers to complete the parts list. I'm building 4x 50W and 1x 100W. Plan to use them for a lot of different things like side-lighting/extending the footprint on my CMH, using them to run smaller runs/strains in the flower room, 12/12 from clones or seeds or breeding in a tent. The many/smaller panels will give me some flexibility to run them where/when I need them. My CMH covers 3x3' and is looking like it will be my primary light but I can run 2x 3x3's or a 3x3 and 2x3 in this room and still have room to move around.
DarthBlazeAnthony
Well-Known Member
I have a 2'9" x 2'9" tent but it's only 6 feet tall. I could put one nice size plant with the scrog I already built. Can we build a light that can cover the space you need to as well as this tent? It's the current setup just trying to decide if I want to build my cob's before starting. Definitely led, hydro, humboldt nutrients. Check out the pics of the tent, scrog, cat, led light, hydroponics, and fans. Cheeers.
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GroErr
Well-Known Member
lol, your cat looks disinterested in your grow, not a bad thing, mine is always trying to get into my rooms and nibble on the leaves 
Nice setup, sounds like you want to get moving on this right away, as I mentioned in my previous post I'm not the guy to depend on to build your light as I'm a newbie with these but if you started a thread to build it, there are lots of great resources here who are always ready to help, as a group I'm sure we can all chime in and get something built.
Since you haven't started yet and will need to make some decisions, get parts etc., you may want to get your current grow going and then switch out the lights when you get them built, not sure how much time you have or how quick you want to get going.
One of the first decisions is going to be coverage. For that size tent I'd say shoot for 300-400W which would be the equivalent + some of say a 600W hps but manageable heat-wise. Then look around at different designs in here and post your preferences, e.g. one large panel, a bunch of individual COB/Heatsink/Fan mini-panels, 2 or 3 mid-size panels etc. Maybe state what skills you have as well, that'll drive some of your decisions, like I suck at anything that requires soldering, tapping etc. I'd either screw it up or take forever so that drove some design/component decisions... Cheers.
Nice setup, sounds like you want to get moving on this right away, as I mentioned in my previous post I'm not the guy to depend on to build your light as I'm a newbie with these but if you started a thread to build it, there are lots of great resources here who are always ready to help, as a group I'm sure we can all chime in and get something built.
Since you haven't started yet and will need to make some decisions, get parts etc., you may want to get your current grow going and then switch out the lights when you get them built, not sure how much time you have or how quick you want to get going.
One of the first decisions is going to be coverage. For that size tent I'd say shoot for 300-400W which would be the equivalent + some of say a 600W hps but manageable heat-wise. Then look around at different designs in here and post your preferences, e.g. one large panel, a bunch of individual COB/Heatsink/Fan mini-panels, 2 or 3 mid-size panels etc. Maybe state what skills you have as well, that'll drive some of your decisions, like I suck at anything that requires soldering, tapping etc. I'd either screw it up or take forever so that drove some design/component decisions... Cheers.
NapalmD
Well-Known Member
Did you have any luck with those #4 self tapping screws with the aluminum heat sink?
AquariusPanta
Well-Known Member
I was originally going to take the self tapping screw route, Napalm, but decided to teach myself about tapping instead. The drilling was a pain in the ass (by hand) but, again, I NEEDED to learn the basics behind this process and everything turned out great, with the exception of a screw breaking off in the HS.
medicinehuman
Well-Known Member
I broke a couple of taps in the heatsinks before, what f'n bummer. I have a drill press now and take my time with the tap. It's much better now
GroErr
Well-Known Member
Yes, I've mounted one that way so far. But you definitely need to drill a pilot hole slightly smaller than the screw and the length of it. Those screws are too small and fragile to try and force/tap them straight in without a pilot. I tried that first and broke the screw, brute force won't work - lol
Mellodrama
Well-Known Member
I've installed about 8 or 9 of these COB's now. I'm still learning, but have a better idea now than before.
Remember earlier in this thread I wrote that it'd be suicidal to use straight-slot screws? I ignored my own advice the other day. Sure enough, the straight-slot screwdriver slipped off the screw and skidded across a new CXA3070. I was so angry I had to stop for a while. There was no visible damage to the CXA so I totally lucked out.
New Rule - do not assemble without magnification. I have one of those hobby visors you wear on your head. Flip the visor down for magnification, flip it up out of the way when not needed. The other day I thought I was done installing a CXA. I inspected it very closely with the visor. There was a tiny particle underneath the COB. That speck of dirt was holding a third of the COB off the sink. Took it all back apart. Found the speck of dirt stuck to the sink. Flicked it off. Put it back together. Inspect. Another speck of dirt. Disassemble. This one was stuck in the paste (TIM) on the back of the COB. I cleaned a finger off with some alcohol and a rag, then swept the dirt off. Cleaned my finger again, and used it to carefully re-smear the TIM across the back of the COB. I was listening to my finger while doing this. If I felt any grittiness at all that COB was going to get an alcohol rinse and we'd start all over from scratch.
I didn't feel any grittiness. I rinsed the heatsink surface with alcohol and buffed it clean. Third time's the charm.
BTW, if you don't have one of these, please consider getting one. Load it up with at least that 91% alcohol (don't waste your time with the standard 70%) and you'll have a super handy tool for COB work. Also very useful for cleaning up after pipe maintenance, etc.
WTH, rollitup still hasn't made hyperlinks more obvious???
I've written previously that these Ideal COB holders shouldn't be installed on a surface that's too small. The holders have four contact points - two metal dimples and two white plastic feet - that are supposed to rest against the sink, as shown in stardustsailor's excellent #11 post in this thread. It drives me nuts when I see guys showing their COB holders hanging off the top of the CPU heatsinks. That's NOT the proper application for these COB holders. The sink must be large enough to contact all four points if you want the holder to function as it was intended. As we've seen, you can get away with two contact points. But it's not the correct way to do it.
Lest you think I'm just being a perfectionist, let me explain how important this is. Let's do an experiment. Install an Ideal COB holder without a COB. Start tightening the screws. As the screws start to bear down on the holder, the entire holder flexes so that the two white plastic feet make contact. Untwist the screws a half turn - the holder unflexes and the white plastic feet lift. Tighten the screws, watch the holder flex and the feet touch down.
Now take it all apart and install with a COB. As has been discussed earlier, these holders don't bear down on the COB very hard. If the white plastic feet don't touch down when you torque the two screws, something's wrong. The answer is NOT NOT NOT to torque the two screws down harder. The proper response is to inspect your work very closely. Either the COB slipped partway out of the holder, or there's dirt under the COB. I described above how I had to disassemble and clean 3X before finally getting it right. The two times there was dirt between the COB and the sink, the white plastic feet would not set against the sink even though the screws were snug. When I finally got the contamination out of the COB's contact patch, the white plastic feet finally made contact with the sink. So, during that last quarter turn of the two screws, watch those white plastic feet. What they do is a good indication of whether you're on track or not.
If you're using an under-sized heat sink you lose that indication.
Something else I've started doing that you might find helpful. With the COB in place, and the screws just barely snugged, I've started reaching between the holder and the COB with a very. very small screwdriver. You know how the Ideal holder has that little spring arm that's supposed to hold the COB positioned during installation? I'll go to the opposite side of the COB and reach in there with that screwdriver. Then I'll exert a tiny amount of leverage. I just want to see the COB move against the spring arm, then move back when I stop levering with the screwdriver. The COB can pop partially out of the little pocket that it's supposed to stay in during assembly. With the holder snug but not yet tightened, the screwdriver trick tells me that the COB's properly positioned and can't be damaged by tightening the screws the rest of the way.
Although I've tried to explain this as clearly as possible, it will all sound like nonsense to those of you who haven't used the Ideal COB holders. Hopefully it'll make some sense to those who have.
Remember earlier in this thread I wrote that it'd be suicidal to use straight-slot screws? I ignored my own advice the other day. Sure enough, the straight-slot screwdriver slipped off the screw and skidded across a new CXA3070. I was so angry I had to stop for a while. There was no visible damage to the CXA so I totally lucked out.
New Rule - do not assemble without magnification. I have one of those hobby visors you wear on your head. Flip the visor down for magnification, flip it up out of the way when not needed. The other day I thought I was done installing a CXA. I inspected it very closely with the visor. There was a tiny particle underneath the COB. That speck of dirt was holding a third of the COB off the sink. Took it all back apart. Found the speck of dirt stuck to the sink. Flicked it off. Put it back together. Inspect. Another speck of dirt. Disassemble. This one was stuck in the paste (TIM) on the back of the COB. I cleaned a finger off with some alcohol and a rag, then swept the dirt off. Cleaned my finger again, and used it to carefully re-smear the TIM across the back of the COB. I was listening to my finger while doing this. If I felt any grittiness at all that COB was going to get an alcohol rinse and we'd start all over from scratch.
I didn't feel any grittiness. I rinsed the heatsink surface with alcohol and buffed it clean. Third time's the charm.
BTW, if you don't have one of these, please consider getting one. Load it up with at least that 91% alcohol (don't waste your time with the standard 70%) and you'll have a super handy tool for COB work. Also very useful for cleaning up after pipe maintenance, etc.
WTH, rollitup still hasn't made hyperlinks more obvious???
I've written previously that these Ideal COB holders shouldn't be installed on a surface that's too small. The holders have four contact points - two metal dimples and two white plastic feet - that are supposed to rest against the sink, as shown in stardustsailor's excellent #11 post in this thread. It drives me nuts when I see guys showing their COB holders hanging off the top of the CPU heatsinks. That's NOT the proper application for these COB holders. The sink must be large enough to contact all four points if you want the holder to function as it was intended. As we've seen, you can get away with two contact points. But it's not the correct way to do it.
Lest you think I'm just being a perfectionist, let me explain how important this is. Let's do an experiment. Install an Ideal COB holder without a COB. Start tightening the screws. As the screws start to bear down on the holder, the entire holder flexes so that the two white plastic feet make contact. Untwist the screws a half turn - the holder unflexes and the white plastic feet lift. Tighten the screws, watch the holder flex and the feet touch down.
Now take it all apart and install with a COB. As has been discussed earlier, these holders don't bear down on the COB very hard. If the white plastic feet don't touch down when you torque the two screws, something's wrong. The answer is NOT NOT NOT to torque the two screws down harder. The proper response is to inspect your work very closely. Either the COB slipped partway out of the holder, or there's dirt under the COB. I described above how I had to disassemble and clean 3X before finally getting it right. The two times there was dirt between the COB and the sink, the white plastic feet would not set against the sink even though the screws were snug. When I finally got the contamination out of the COB's contact patch, the white plastic feet finally made contact with the sink. So, during that last quarter turn of the two screws, watch those white plastic feet. What they do is a good indication of whether you're on track or not.
If you're using an under-sized heat sink you lose that indication.
Something else I've started doing that you might find helpful. With the COB in place, and the screws just barely snugged, I've started reaching between the holder and the COB with a very. very small screwdriver. You know how the Ideal holder has that little spring arm that's supposed to hold the COB positioned during installation? I'll go to the opposite side of the COB and reach in there with that screwdriver. Then I'll exert a tiny amount of leverage. I just want to see the COB move against the spring arm, then move back when I stop levering with the screwdriver. The COB can pop partially out of the little pocket that it's supposed to stay in during assembly. With the holder snug but not yet tightened, the screwdriver trick tells me that the COB's properly positioned and can't be damaged by tightening the screws the rest of the way.
Although I've tried to explain this as clearly as possible, it will all sound like nonsense to those of you who haven't used the Ideal COB holders. Hopefully it'll make some sense to those who have.
stardustsailor
Well-Known Member
Very good observations ,indeed.
churchhaze
Well-Known Member
Found this while looking for stuff on the 50-2102CR holder for cxb2530. I also like the heat sink he's using for this cob... it's an interesting choice.
One of these with a reflector would make an AWESOME desk lamp.
One of these with a reflector would make an AWESOME desk lamp.
Mellodrama
Well-Known Member
I know some of you are perfectly happy with the thermal adhesive. I'm not saying that's wrong. I just don't like the idea. I just got to thinking this morning - what if I'd been using glue instead of paste while trying to assemble the LED as described above in Post #49?
With paste I had all the time in the world to inspect the build, realize there was a fleck of dirt in there, disassemble, reassemble, disassemble again, etc. I'm wondering how many guys have glued their COB's to heatsinks with a piece of dirt in between...
Also, I keep reading about guys breaking taps. Taps are made from a very hard, very brittle steel. They will not take flexing. I imagine most taps are broken because someone who doesn't know how brittle they are twisted too hard. Some taps are broken because of side-loading. I broke a taper tap a few months ago when the tap went all the way thru the heat sink's base material. I hadn't centered the hole between fins, so as I continued threading the tap started riding up on the side of a fin. One side of the tap was bearing against a fin and the other side was in mid-air. I snapped that tap in half without even trying.
Use a small roofing square and a scribe to scribe a line on the heat sink surface that's as close to equidistant between fins as you possibly can. Then drill your holes as straight as possible. With any luck at all the drilled hole will pop out between the fins.
With paste I had all the time in the world to inspect the build, realize there was a fleck of dirt in there, disassemble, reassemble, disassemble again, etc. I'm wondering how many guys have glued their COB's to heatsinks with a piece of dirt in between...
Also, I keep reading about guys breaking taps. Taps are made from a very hard, very brittle steel. They will not take flexing. I imagine most taps are broken because someone who doesn't know how brittle they are twisted too hard. Some taps are broken because of side-loading. I broke a taper tap a few months ago when the tap went all the way thru the heat sink's base material. I hadn't centered the hole between fins, so as I continued threading the tap started riding up on the side of a fin. One side of the tap was bearing against a fin and the other side was in mid-air. I snapped that tap in half without even trying.
Use a small roofing square and a scribe to scribe a line on the heat sink surface that's as close to equidistant between fins as you possibly can. Then drill your holes as straight as possible. With any luck at all the drilled hole will pop out between the fins.
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redbluishgreen
New Member
So .. I'm a total novice DIYer and right now I'm experimenting with building a bin much like Gaius "baldurs bud bin" Just to feel things out. I'm not trying to re-invent the wheel here. everyones done a lot of hard work so I'm simply using the same parts, placing things in the same order, trying to make my first build as SIMPLE as possible.
However this seems to be an option with pros and cons.
if you use a COB holder you most likely don't have to solder anything. However you do have to drill into your heat sink which after some reading here seems to require a drill press, and more knowledge than I currently have on how to accomplish the task.
if you go the route stated by Supra you can hook the cob up relatively easily to the heat sink. Nothing too technical there really. Kinda like gluing popsicle sticks when I was a kid. However then you are left with soldering. Which I have 0 experience with at the moment.
Now I'm going to build this thing, and hopefully not waste a bunch of COBs learning how.
So given my 0 experience with COBs and being a complete novice DIY (but enthusiastic interest) in this project, what method would the more experienced people recommend for attaching the cob to the heat sink and attaching the cob to the driver for me?
Is there a third option? some blend of the two, avoid soldering and avoid drilling? Could a person perhaps use thermal paste to connect the cob to the heat sink, and then use tape to hold both the cob and place the cob holder allowing for the wires to run into the cob holder and create the connection?
Either way I figure I'm probably gonna do a little damage to myself and a little damage to the cob trying to get this right. Can't make an omelette without breaking a few eggs. None the less I would like to start small and simple. Gradually increasing my skill level with the tools and methods to build bigger better projects in time.
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SupraSPL
Well-Known Member
I went through quite a learning curve when it came to soldering LEDs. The one thing that makes it so much easier (for me) is flux gel. It makes heat transfer much faster and acts like a wetting agent, allowing the solder to flow to all the metal surfaces quickly and neatly. 63/37 lead solder melts at a low temp so much easier to work with, especially with a low temp iron. Most solder incluse flux, but I solder one handed so that does not help me and some would argue you need more flux that what is inside the solder. If you are going with the solder method, I recommend:
Weller solder iron $19 OR
cheap solder iron $6
63/37 lead solder $5
flux gel syringe $11 OR
flux gel tub $4
You could get everything you need to solder perfect joints for as little as $15. The method I use, put some flux on the COB solder pad and the stripped wire, apply solder to the iron tip, touch the iron tip to the flux and it will suck the solder into place almost instantly. Once you have the COB solder pad and wire tip tinned, touch them together, bring in the iron and they will melt together forming a perfect joint. You can add some flux for the last step but not necessary. And finally, clean up the excess flux around the joint with alcohol.
Traditional solder technique would have you melt the solder directly onto the target rather than onto the iron tip, but I prefer the one handed method because it frees your second hand to hold the wire. Having the solder hot on the iron also helps when you are soldering something that is mounted onto a gigantic heatsink.
Weller solder iron $19 OR
cheap solder iron $6
63/37 lead solder $5
flux gel syringe $11 OR
flux gel tub $4
You could get everything you need to solder perfect joints for as little as $15. The method I use, put some flux on the COB solder pad and the stripped wire, apply solder to the iron tip, touch the iron tip to the flux and it will suck the solder into place almost instantly. Once you have the COB solder pad and wire tip tinned, touch them together, bring in the iron and they will melt together forming a perfect joint. You can add some flux for the last step but not necessary. And finally, clean up the excess flux around the joint with alcohol.
Traditional solder technique would have you melt the solder directly onto the target rather than onto the iron tip, but I prefer the one handed method because it frees your second hand to hold the wire. Having the solder hot on the iron also helps when you are soldering something that is mounted onto a gigantic heatsink.
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churchhaze
Well-Known Member
Soldering stranded 18awg wire to vero has gotta be the easiest soldering job you'll ever have to do. Thinner gauge? Even easier. It should only take 5 seconds of heat on each pad before it gets hot enough to take a tin.
redbluishgreen
New Member
Seems like everyone prefers the cree. how do the veros stack up against the crees? for simplicity sake it sounds like the vero would be an easier installation for a first timer, but is that a trade off with performance?
and most importantly Thank you for the replies. Thank you for the information, and thank you for the patience.
