COBs by string, or COBs by rail?

Hydropat

Hydropat

Active Member
I tried desperately to come up with a corn-on-the-COB joke, but sadly the ganja didn't bring any comedic inspiration this Friday night... :weed:

Anyway, just kinda throwing this out there. I've recently sent emails out to my prospective supply chain (Jerry!) as I look to piece together a few fixtures, and I have flexibility on how I design some of them. I've designed smaller form-factor lights in the past, and have perused most of the approaches to mounting and thermal dissipation in this subforum and elsewhere. That said, I have two distinct options for two of the 5-6 planned fixtures:
  1. A string of COBs sharing a driver, each COB with its own heatsink (whether active or passive) ventilated in a vertical fashion.
  2. A rail of COBs sharing a driver, each COB mounted on the bottom of a long heatsink which is then encased in an aluminum tube for active "duct-style" horizontal ventilation.
Thermal pros and cons aside (advantages of passive vs. the rail's requirement of at least minimal active), the former option has a more flexible footprint (i.e. cover a 1x4, or curve the string to fit a 2x2) while the latter uses fewer components and is arguably easier to mount, handle, and extend. I can build one of each option, or two of one of them. Assume relatively equal performance between the two. Either approach would fit my environment reasonably well, but then I'm not building them for myself (environment is supposedly TBD)... and if I build more in the future, they'll be for you guys and others... so I need a few more opinions on this.

I have documentation and numbers to go with both of these options, but I'm more interested in your thoughts on the two form factors than comparative analysis of the technical details. If you're like me, and the details are what really paint the picture, let's use the fits-like-a-glove example of 1:4 HLG-185H-C1400 to CXB3070.

So what say we? String, or rail?

pat :bigjoint:
 
Hydropat

Hydropat

Active Member
Life pulled this down my list of priorities for a while, but thankfully it's eased up. Glad to get back to it for sure. A picture is worth a thousand words, no?

Recent progress:

IMG_20151117_233008.jpg

From right to left, HeatsinkUSA 4.900" at 46", 2x6" rectangular tubing at 48" with cutout for HUSA to be placed, and finally the two of them positioned together... though they have yet to actually be welded (wood spacers used for the photo). Here it is rendered via CAD, looking at the profile:

cob-rail-heatsink4900.png

Two vents will be milled in the top of the 'duct', near the center, for 12v pushing fans (MW APV-12-12).

ttystikk said:
So is it COBs by string
or rather COBs by rail?
My head is in the ScrOG
Can't see head nor tail.
So we ask the wise ones...
T'would suck for this to fail!
Click to expand...
I would like this, but apparently I don't yet have the ability. Here's a nice fan leaf instead: :leaf:
 
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Hydropat

Hydropat

Active Member
Rahz said:
I'm not sure how that would work
Click to expand...
That makes two of us haha. I'm still debating whether each light on the string should be individally suspended or if they should be attached to an aluminum or steel rod which is then suspended from the ceiling. The former is more flexible, the latter significantly easier to hang (in theory).

Rahz said:
but it sounds pretty bad ass.
Click to expand...
That's the plan :bigjoint: we'll see how it all comes together.
 
ttystikk

ttystikk

Well-Known Member
Hydropat said:
That makes two of us haha. I'm still debating whether each light on the string should be individally suspended or if they should be attached to an aluminum or steel rod which is then suspended from the ceiling. The former is more flexible, the latter significantly easier to hang (in theory).



That's the plan :bigjoint: we'll see how it all comes together.
Click to expand...
Pics might help us visualise what you're doing a little better?
 
Hydropat

Hydropat

Active Member
ttystikk said:
Pics might help us visualise what you're doing a little better?
Click to expand...
As far as the strings go, I don't yet have much to take pictures of. Perhaps I'll put some drawings together. I was just seeing if there would be much interest in a vaguely "string" like fixture, not unlike oversized christmas lights. Rest assured that as soon as I have materials in hand, I'll post some photos.

cob-assembly.png

Here's a CAD rendering of a passive vertical heatsink, cover plate with vents, holder, lens, and 3590. The part thumbnail in that image at middle left shows a wider view of the assembly. So eight of those, on a string, positioned every 12, 18, or 24 inches.
 
ttystikk

ttystikk

Well-Known Member
Hydropat said:
As far as the strings go, I don't yet have much to take pictures of. Perhaps I'll put some drawings together. I was just seeing if there would be much interest in a vaguely "string" like fixture, not unlike oversized christmas lights. Rest assured that as soon as I have materials in hand, I'll post some photos.

View attachment 3545978

Here's a CAD rendering of a passive vertical heatsink, cover plate with vents, holder, lens, and 3590. The part thumbnail in that image at middle left shows a wider view of the assembly. So eight of those, on a string, positioned every 12, 18, or 24 inches.
Click to expand...
Now I got it. I like!

Nice rendering, too. Seems CAD has come a long way since AutoCAD release TEN! From 1986!! Fuck I'm getting old...
 
Hydropat

Hydropat

Active Member
ttystikk said:
Now I got it. I like!

Nice rendering, too. Seems CAD has come a long way since AutoCAD release TEN! From 1986!! Fuck I'm getting old...
Click to expand...
I've been using Autodesk's Fusion 360 lately... it's free for hobbyists, enthusiasts, and startups, and is cloud-based (including raytracing). Good deal, but still has some usability issues,

Heard from Jerry today, sounds like the 3590's are shipping on Tuesday. :)
 
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