LED Group buy!

[that0neguy1126]

hey derek, how about another group buy? ....

All you buddy!

Dan, Gale, Anyone else. I can head down to the post office tomorrow and ship them out. PM me your address. It's $5.20 for the small box, should be big enough for anyone.

 

[Crit21]

This has been a royal PITA for Derek, and a little bit for me. I think any GB should be someone else's headache.

 

[that0neguy1126]

Ok, Gale, Dan, I sent yours out just a few minutes ago. Sorry for the delay, figured I would go to the post office after I got off work, but they didn't open till 9am, and I was asleep by then, and by the time I woke up they were already closed.

I also picked up some extra boxes, if anyone else wants me to send them via priority mail/flat rate box, PM me your address.

 

[Cake_Boss]

Sorry I flaked on you. I'll see when I'm going down there again

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[Zooid]

Thanks Derek

 

[Crit21]

Ok. I sent a PM just before seeing this thread.

 

[Cake_Boss]

How are you guys attaching the LEDs to the heatsink? Just using thermal paste is a poor way to do it says my future father in law, who is an EE.

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[Zooid]

I drilled and tapped the heatsink and used Arctic Silver thermal paste. Used #4-40 nylon screws to hold the stars onto the heatsink.

 

[Cake_Boss]

Yup, he said to use screws those are what is transferring the heat from the LED to the heatsink

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[that0neguy1126]

Well the LED die's are mounted to an aluminum star that acts as a heatsink. You mount these to a larger peice of aluminum (and a fan if needed) to transfer the heat. Very little heat transfers through most screws (unless they are aluminum as well). Plus if you use metal screws, you have to make sure not to short circuit them, the stars are pretty tiny, so its easy to do.

Nylon screws would be the best, but there is some concern about them slowly slipping loose.

Due to the pure number of LEDs I used, there was no way I was drilling and tapping ~500 holes. So I decided to by "Thermal Adhesive" which is different from just "Thermal Grease" The Adhesive is also a 2 part epoxy that works to glue the LED's to the larger aluminum heatsink and fan, it also is like 98% silver, so it works as a Thermal grease as well.

Jaime I sent you a PM, will be sending yours out tonight, should get to you by Friday.

 

[Zooid]

Derek,
just sent the money for shipping...sorry it took so long.

 

[Cake_Boss]

Got the pm, thanks. I'll show some pics when we do the build. Should be a sweet sump light.

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[68RUSTANG]

My drivers should be here this week.

I'm thinking of using pop rivets and plastic washers to attach the stars, any thoughts?

What would be a good thermal grease to use for this application?

Aloha,

Tony

 

[Zooid]

buy some Arctic Silver paste, not the epox. I bought mine off Ebay.
Pop rivets with plastic may work, depends on what you are mounting the stars to.

 

[68RUSTANG]

Stars will be mounted to a .125 sheet of aluminum. I am planning on building 12" x 12" lights with the drivers, fans, slide pots enclosed in a hood.

 

[Cake_Boss]

Stars will be mounted to a .125 sheet of aluminum. I am planning on building 12" x 12" lights with the drivers, fans, slide pots enclosed in a hood.

pics?

 

[Zooid]

Well, a couple days ago I lost one of those cheapo Chinese drivers. Has anyone else lost one yet?
I hooked up a Meanwell with a homemade dimming circuit and I can finally dim the LED's slowly and
accurately instead of using the rheostat which caused erratic dimming with the Chinese drivers. Hmmmm
I may have to set up both of my Meanwells to use on my light now...

 

[Crit21]

Mine are still fine after a full year.

You realize Mean Well is made in China too.

 

[Zooid]

Yes but the meanwell's seem to have better quality assurance and the dimming circuit definitely works better.

 

[Crit21]

Could be.