Reef Discussion

[the cichlid kid]

Hello Reefugees,

I know you lot love your DIY so I'm hoping you may be able to help?

I'm was just doing an online search for the bits and pieces required to make my own algae turf scrubber. Basically looking to copy the same design as the SantaMonica ATS' (the hang on version). The part I'm struggling to find is a heat sink that is identical or similar to the ones they use.

http://www.santa-monica.cc/Heatsink-for-the-LEDs-on-all-HOG-scrubbers_p_24.html

I've looked on eBay and tried google for a local (Australian) source for these with not much luck.

Can anyone point me in the right direction?

Cheers,

Beau

 

[MagicJ]

Any idea on the rough dimensions of these? They look similar to the heat sinks used on some high power electronic parts, but only if they are reasonably small.

 

[the cichlid kid]

Any idea on the rough dimensions of these? They look similar to the heat sinks used on some high power electronic parts, but only if they are reasonably small.

I don't know exactly but they would be approx 60mm x 40mm and I'm not sure on depth.

 

[the cichlid kid]

http://www.santa-monica.cc/Outside-half-of-the-HOG1x_p_56.html

You can see in this pic that you would fit approx 3 of the star shaped PCB's across the length and about 2 across the width

 

[shaidas]

Just use CPU heat sinks like this guy

2 bucks off ebay

http://www.ebay.com.au/itm/5pcs-22x...4f45f696585fcfa96893b4&pid=100506&rk=1&rkt=1&

 

[Sean81]

These guys deliver free. If you search thru all their heatsinks you might find better but quick search found this one. Just keep in mind some of these are heavier if you hanging by magnets.

https://au.rs-online.com/mobile/p/heatsinks/2342485/

 

[DavidS]

I got a couple of cheapish thin and light ones on ebay, then rear mounted fans on them to cool. They were cooking LEDs within seconds without fans, but as soon as I put on 30mm fans, they were fine.

 

[MagicJ]

This would be a bit of a guess, but these LED's wouldn't need a lot of current going through them - maybe 300mA?? - so they shouldn't get very hot?

 

[shaidas]

This would be a bit of a guess, but these LED's wouldn't need a lot of current going through them - maybe 300mA?? - so they shouldn't get very hot?

Good point.. Most of the DIY builds I have seen dont seem to use any. Specially the upflow types which use lights on only one side

 

[DavidS]

This would be a bit of a guess, but these LED's wouldn't need a lot of current going through them - maybe 300mA?? - so they shouldn't get very hot?

Hahaha, you'd be surprised! (I was). The heatsinks I used were really, really lightweight, but got really hot quickly and the LEDs kept blowing. A couple of tiny fans made all the difference in the world. They get power from the same driver that runs the LEDs. Adding the fans has kept them practically cold with no real noise addition. The LEDs I'm using were rated at 500mA, but I dropped them down using my workbench power supply, and they still wound up too hot without cooling.

 

[MagicJ]

@DavidS - any idea what the final current actually was?

 

[shaidas]

Hahaha, you'd be surprised! (I was). The heatsinks I used were really, really lightweight, but got really hot quickly and the LEDs kept blowing. A couple of tiny fans made all the difference in the world. They get power from the same driver that runs the LEDs. Adding the fans has kept them practically cold with no real noise addition. The LEDs I'm using were rated at 500mA, but I dropped them down using my workbench power supply, and they still wound up too hot without cooling.

Thats strange. What was the config mate ? Santa Monica does 4 -7 5 watts with just heat sinks and as far I can see the heat sinks are just straight aluminium, no fins. None of the other commercially available scrubbers have fans in them.

 

[DavidS]

@DavidS - any idea what the final current actually was?

I wound up using drivers that run at 300mA by the time I put it on the tank. The fans run off the drivers as well - they use about 0.2w so they're not exactly putting much load on it.
The LEDs are absolute cheap $h!t lol.

 

[DavidS]

Thats strange. What was the config mate ? Santa Monica does 4 -7 5 watts with just heat sinks and as far I can see the heat sinks are just straight aluminium, no fins. None of the other commercially available scrubbers have fans in them.

There are heatsinks and there are heatsinks. Fins are pretty useless you have air running over them, so without active cooling, there's no point in them using them. A solid chunk of aluminium would disperse a lot more heat than a light weight heatsink, but is obviously heavier.
One of my build considerations was that appropriate magnets are bloody expensive - especially in the size required, so I needed to keep the weight to a minimum, so I used the smallest heatsinks I could get away with. The fans add literally a couple of grams, no real noise, and ensure that the whole thing produces no heat - which I'm a fan of this time of year. I could probably have avoided the issue by using heavier heatsinks.. but then, my other build consideration was to spend the least amount of money possible, so I wasn't going to risk going too heavy for the magnets I had, etc.

 

[the cichlid kid]

Thanks for all the help and feedback guys

 

[MagicJ]

Thanks for all the help and feedback guys

What did you end up doing?