Let's talk DIY lights


#1404

I don’t know what shipping was but the drivers were $51 each. That already puts me over Sager even if shipping is free.


#1405

Shipping is indeed free over $20, overnight shipping at that. But you’re not in a huge hurry, so save the money.

If you haven’t already, create an account at arrow anyway when you get time. A few times a year they will run 10% discount and you should get email notification.


#1406

Regarding heat transfer: Bridgelux says in the Vero29 datasheet NOT to use thermal transfer tape for the Vero29s, or even the next smaller size down. It might not matter if you are running them at 1/2 maximum or less, but it wouldn’t hurt to try to measure the difference between cob temperature and the heat sink. It should be maybe 5 degrees or so. If it’s a lot more, then you need to change from transfer tape to Arctic Silver Alumina Thermal Adhesive (Walmart.com) or some microprocessor TIM goo.

I have been using the goo, but I just bought some of the Alumina Adhesive for only about $6. One difference: It is permanent. You can’t ever get the COBs off the heat sink once you use it.


#1407

Exactly what I was thinking by asking if he had case temps.


#1408

I suspected it would be a quiet day at work, so I brought a few things along. I think we have progress @MattyBear @Covertgrower @MAXHeadRoom


#1409

Good to know, I used the tape because it was what rapid recommended and sold as part of the kit.


#1410

I love this! @dbrn32 sexy looking lights!


#1411

Slow days are great for us growers! We get to spend more time on our hobbies lol. Nice work on that frame. Wish I could just pay you to build me something like that lol


#1412

She has a ways to go. Those are my $10 heatsinks. They’re drilled and tapped for ideal holder, but that’s it. I have to layout mounting holes, drill, and tap. No big deal, just didn’t get to it.

Cob centers are going through be 14.5” on what I’ll mount as side to side, and 12” front to back. But it gave me enough room that I should be able to flush mount the board. So I don’t have to use stand-offs or anything, which was my original concern it may shade cobs.

I was thinking about mounting drivers to frame on this one. I think I’ll need some square tubing instead of channel I already bought. Run them as cross members inside of frame with slate 2 mounted to bottom and drivers on top. What do you think?


#1413

That sounds right, and you would obviously know more than me lol. I know my driver and heat sinks don’t get very hot at all so they disperse heat really well. And it’s mounted on top as you know.


#1414

Good good! This would technically have like a 3/4” gap, or whatever size tubing I buy. But exact same principle. The frame is just bigger than heatsink, so i need to put something in there anyway.


#1415

Look at what I brought home haha! I’ll be posting my shopping list for review if you don’t mind. …

1" X 6" X .125". They will need a good sanding.


#1416

Saaaaweeeet! Post it up, I’ll take a look.


#1417

I think square tubing would be just right. @dbrn32 it should sit above the angle just a bit if you find the right size. Then the board would sit under that, and shouldn’t shade the COB’s.


#1418

What would you recommend for thermal transfer? Silver adhesive or tape and what thickness would you suggest for tape?


#1419

This stuff right here is what I used. Pretty sure @BIGE went with same stuff.

Works very well at transfer and mounting the strips. I would consider it non-removable though.


#1420

I wouldn’t recommend tape unless you were mounting 3 watt individual LEDs. Bridgelux has a whole white paper devoted just to heat transfer and heat sinks. For 50 watt+ COBs they say to use a thermal grease (like Arctic Silver) or a thermal epoxy (like Arctic Alumina Adhesive). The former can be disassembled and cleaned off. The latter is permanent. There are plenty of other manufacturers of similar products.

That tape would be very good for fastening aluminum collector plates onto copper tubing in DIY solar water heating panels. Most of the DIYers use silicone caulk now to exclude air. That tape is probably a lot better.


#1421

I’m going to use with some eb strips and want best heat rejection possible.


#1422

They are rated and binned for use without any heatsink or transfer material. So anything is going to be better. The tape is not only fine, it does a really good job when used properly.


#1423

It should be great for strips. I would use it under the 3 watt stars, too.

I think the color matters, too. XP-E HE Photo Red LEDs hardly degrade at all even when you run them at high current and hot. White LEDs and COBs are all basically blue LEDs that do suffer a lot of loss when they are hot. Green are very bad too (not that we use them). Each different color is a different chemistry, so it doesn’t surprise me they have different sensitivity to heat.

White COBs are really fluorescent lamps! Instead of a mercury arc stimulating several different phosphors, they use a blue LED to stimulate the phosphors. Different spectra come by using different phosphors and proportions. But heat is the blue LEDs enemy, so it affects how lit up all the phosphors get.