My girlfriend's PlanetBike Dual-Spot bike light bulb blew last month (sorry dear, the HID is for ME ME ME). It featured a mini halogen bulb and a single 5mm white led powered by 2 AA's. Sooooooo, since the incan was burned and the cheapy led was practically useless, I decided to yank out the innards and see what I could do with a Lux III setup.
I set the following criteria for this, my 2nd major mod attempt ever, bike light project:
1) It had to have self contained rechargeable batteries w/socket to connect the charger
2) It had to last for at least 20 mins
3) It had to have a decent heatsink since the case is plastic
4) It had to output more light than the stock incan/led setup
5) It had to look like the stock light when finished
My parts list:
2 Batteryspace RCR123A's
T bin Luxeon III Star
Luxeon Lens Holder
15 Degree Lens
Video card heat sink
Misc parts from a plastic Harrier model
Here is the documented buildup:
Behold! The Planet Bike Dual-Spot light.
The AA caddy and the case opened
The stock internals
Exploded view of the new lighting assembly
I had to fit that black lens mount into that reflector
Dremel to the rescue!
The holder and lens fitted
In addition to the new lens, I had to use the original integrated cover/lens because it was part of the mounting design. Also, it keeps the light looking 'stock'.
I took 1/2 of a nose cone from a Harrier airplane model that was laying around and molded it to the top of the case. This is the hot air exhaust for my heatsink design.
This is the rear view of that exhaust
Using part of the Harrier canopy, I made an air intake scoop.
Another view of the intake scoop
This is what the case looks like put together. Air enters from underneath, flows over the heatsink, and out the top vent.
I mounted the RCR123A's this way and added a slide switch to the battery cover. I used a slide switch because of the limited amount of space.
View of the switch with the battery cover on. This cover will be closed with epoxy later.
The parts were painted flat black and flat grey.
Here is the recharging jack. It was screwed into the case by a few threads and then glued in with 5-min epoxy.
Almost done! The heatsink was mounted to the Lux with Arctic Alumina Thermal Epoxy. The case was sanded again with 600grit and a 2nd coat of paint applied.
The 1000mA BuckPuck being wired up and mounted with hot glue.
Ta da! All done!
Rear view. I really like that charging jack.
Mounted on the bike. The blue dot you see is the back of the black anodized heatsink.
Here is my charging setup
How it was mounted in my testing box. Since this light is meant to be used on a moving bike, I had to mount a fan in front of it to get airflow over the heatsink.
Unit fired up before closing the lid to start logging
BEFORE MOD - Shutter 1/2 f 3.5
AFTER MOD - Shutter 1/60 f 5.6 I think this picture is deceiving. Since the light was so spread out and intense, the camera changed the shutter/aperture to prevent it from being blown out. This made the Before and After look almost the same. Trust me, the after was MUCH brighter.
Hallway shot. This is a better representation of the output. There is no way a single 5mm white led can throw this!
And the runtime plot. X=Minutes Y=Measured Output (mA)
After hours of grinding, cutting, and sanding, I feel that I met and exceeded most of my criteria so I'd call this mod a success!
I was surprised to get 50 minutes of regulated output from it. I charged the light after it cooled and it took 131 minutes @ .15A. I may just send this over to the folks at Planet Bike in hopes of free stickers or something.
edit: I had a chance to ride around the neighborhood tonight and am very happy with the light. The 15 degree lens evenly lights up a good portion of the landscape in front of me. I think it's much easier on the eyes because there isn't a hotspot for an object to suddenly appear and then disappear in the darkness as you run it over. I posted beamshots in a response below.
All comments and/or criticism are welcome!