DIY Light

[RedBike]

I'm making a rear light. Can anyone suggest any betters ways of doing it.

I'm going to use an old computer heatsink then attach two red 5w LEDs to it with thermal adhesive
http://cgi.ebay.co.uk/ws/eBayISAPI.dll?ViewItem&ssPageName=STRK:MEWAX:IT&item=260321272369
http://cgi.ebay.co.uk/Thermal-Adhesive-Tape-Sticker-for-Desktop-PC-Heat

The driver will be this one (Also stuck to the in heatsink)
http://cgi.ebay.co.uk/ws/eBayISAPI.dll?ViewItem&ssPageName=STRK:MEWAX:IT&item=250334113230
http://cgi.ebay.co.uk/ws/eBayISAPI.dll?ViewItem&ssPageName=STRK:MEWAX:IT&item=270319244543

Then to make everything stuck to my heatsink is waterproof i'm going to poor epoxy resin over it all
http://cgi.ebay.co.uk/Epoxy-Resin-G...14&_trkparms=72:1301|66:2|65:12|39:1|240:1308

It will all be powered by this
powered from 8 x AA batteries (9v).
http://cgi.ebay.co.uk/ws/eBayISAPI.dll?ViewItem&ssPageName=STRK:MEWAX:IT&item=270319244543

I just need a way of fastening this lot on and waterproofing the batteries.

 

[RedBike]

I don't think I need any lenses as I 'think' I want the maximum 120 deg range.

Perhaps I would want 15deg?
http://cgi.ebay.co.uk/ws/eBayISAPI.dll?ViewItem&ssPageName=STRK:MEWAX:IT&item=270191153253

 

[gbb]

Going by my 1x 3w Luxeon Star front light, two 5W on the rear is going to blind everyone Red
Couple of things..
you wont see the rear light (in the normal way) from the side. The lens will simply project the beam rearwards. Its not like a wraparound lens where it can be seen from all angles. (athough i suspect the beam will be as bright as a laser )
Watch out for the thermal epoxy for fixing the LEDs to the heatsink. Its about £7 a tube. (mine was anyway) You should be able to screw the LEDs to the heatsink instead.

In your impatience to see it working, dont try to connect the batteries to the LEds without the driver....you'll probably blow the LEds in a millisecond (i know...i did )

 

[bonj2]

i once tried to make a front, and it's much more expensive and effort than it's worth.
the electronics isn't the hard bit, the housing is the most difficult bit. What are you going to put it in?

 

[gbb]

i once tried to make a front, and it's much more expensive and effort than it's worth.
the electronics isn't the hard bit, the housing is the most difficult bit. What are you going to put it in?

That was true of my front light. I (in my impatience to get it going) used a real cheapo light that ran on 4 AA batteries (just right...and no need to think about where to mount the battery pack), removed the optics and inserted heatsink, optics and LED. It works very well. Cheap and nasty, but it works.

I was thinking about this last night Red...If your heatsink will allow it, can you file a half round section onto it, back it with rubber to sit round your seat tube and maybe drill a hole through the body and cable tie it round the seat tube.

 

[RedBike]

I was simply going to bolt the heatsink straight onto my pannier rack.

I have choice of a few heatsinks that have all been pulled out of old computers.

I'm still working on the batteries. I'm looking at just making the connection wires long enough to allow me to have the batteries in the side pocket of my pannier bag.

 

[RedBike]

Going by my 1x 3w Luxeon Star front light, two 5W on the rear is going to blind everyone Red

They will only be 2 x 180 lumens. Thats certainly a lot brighter than any other rear light i've seen but it's not blindingly bright

It's a shame I can't find a driver that would cause the LEDs to flash. 360lumens flashing would be blinding!