Hello All, been away a long time since I finished making my mtb lights with all your help. Anyhow, now I'm onto a different project and need a little advice as to heatsinking. What I am making is a replacement "bulb" for the headlight of my vintage vespa. This will use three Cree Q5 Leds driven at 1A for low beam and then the same again (ie two sets of 3 q5s at 1A) when on high beam.
The picture shows the mount/heatsink I have made to put the leds on (awaiting delivery at the moment from dx) incompleted. When finished it will have copper "flats" as seen in the middle repeated either side and the same again on the opposite side of the assembly. Three leds on 14mm round boards mounted on top and three underneath (on opposite side, not visible in the photo). The copper sections are 14mmx20mm to give an idea of scale. The fins are 2mm thick, as are the copper flats which are joined to the aluminium using arctic silver.
This will all slip into the 5 inch diameter headlamp assembly, but what I really want to know is..... do you experts reckon the heatsinking is sufficient. I used seoul p4 leds in my mtb headlights:
http://www.candlepowerforums.com/vb/...d.php?t=166203 these get warm but not too hot. As it is there will be little ventilation inside the headlamp unit. I have no experience with Cree Q5 leds and their heating issues!!!
All the best, Tom