2W heatsink sizes?

I am looking to finally putting a 2W (or around this power, I know it will differ diode to diode) into a permanent hand held host, however, I am also looking to achive at least 3-5 minutes of on time before having to let it cool down.

Other then DTR's and Jayrob's build, I dont know any other sources for sizing referance, so I was wondering if there are any other builds here that can achive this runtime and keep the diode within acceptable tempertures. If so, I do wonder whats the dimentions of the heatsink.

Right now im just planning to use a 2.25" X 2.75" aluminum head with a copper slug as the module that will hold the diode. but I would like to hear some inputs of others who have either built thier own or own a 2W 445. if this will be alright for the desired runtime.

I got a few hosts around as spares and what not, but I will probably design and build a new one for this laser. (for better dissapation and convection of heat, I was originally going to use my retired 445 build with a fatter head attached to it *middle host*).

Thanks for any help and advice.

The guidesman can, as well as ehgemus' 26650 and 32650 hosts.

Wow, so those hosts can do such power for 3-5 minutes and take it easly?

I guess I may just be overestimating the heatsinking these diodes need.

I say use the pepsi can.

lol..

I think almost everyone is over estimating the amount to heatsink needed to achieve long run times. My 1500mW 445 has been left on for 10 minutes before I turned it off just because I was worried about my battery. That was in a 1.25" diameter all aluminum heatsink.



It is very important to have a great driver heatsink though.

http://laserpointerforums.com/f52/2...ive-mohrenberg-heatsink-58842.html#post831516

he ran it for 10minutes

Have you considered active cooling? It does help alot.
2W output power you mean?
That's about 1.9Ax4.5V almost 9 Watt in, leaving 7Watt of heat from a little 5.6mm diode...

Yes, that is what I meant anselm.

Since im downsizing and wanted a unit that will fit into my pocket, I Was a bit concerned about the heat it will dissapate (which I figured was 7-8W as you stated).

I see now that this will probably not be an issue at all for my use.

Either way, the host is getting smaller, but I think the runtime will still be good with the heatsink it will have (bieng 1.5" in diameter).

Thanks for your inputs everyone, they guided me in the right direction on the heatsink size.