Introduction: Awesome Twin Spotlamps
They say that necessity is the mother of all invention.......
Well its winter daylight hours now and I need to keep fit and for me that's cycling in the dark.
I need new bike lights to illuminate the path ahead as I cycle on a lot of unlit and badly maintained cycle paths and I also need to increase my visibility on the open road. After some thought I decided a pair of large diameter spotlamps is the only solution. Only they must be cheap and bright.
Several weeks of going to the carboot sales got me a matching pair of krypton bulb powered torches for 50p each and a trip to the local hardware store got me the rest of what I needed
The result is a pair of awesome bicycle spotlamps.
Step 1: Things You'll Need.
Two matching torches, the sort that take the big 6V batteries with the springs.
Two pipe clips.
Two nuts and bolts.
And a few tools
Blow lamp. (Not essential)
The pair of torches I used were branded UNI-LITE UK200 and were fitted with 3W 6V krypton bulbs. My calculations are that 4 AA Ni-Mh batteries will last for about 3 hours. Experience tells me not to expect more than 1 1/2 hours per set of batteries when both lamps are on.
£1.00 ---- Two torches from a car boot sale at 50p each.
£0.99 ---- Two jubilee hose clamps.
£1.32 ---- Power connectors x 2.
£0.40 ---- Battery holder.
£5.00 ---- New NiMh AA 2000mAh Batteries x 4
Bits from the bits box: (FREE)
Nuts and bolts. Inner tube rubber. innertube etc
Total cost £8.71
Real cost £3.71 (I already have many rechargeable AA batteries)
Step 2: Shortening the Torch.
Carefully measure out where to make two cuts on the torch so that when you take the cut off end bit it matches the hole at the other cut.
I could have made them shorter but would have needed an external switch. Being lasy I choose to use the switches in each torch. They are also a bit waterproof so I wont have to worry about rain in the switch.
After cutting the middle out the end is simply glued into place to make a pair of awesome looking bike lights.
Not photographed is the wires soldered to the battery clips o the back of the reflector shell. These were common to both lamps and a trailing lead went to one of the bicycle front panniers where it connected to a 4 cell AA battery holder.
Step 3: Making the Handle Bar Clip
To make the handle bar clip I brazed the M5 screw onto the pipe clamp.
I brazed them together as I have the equipment. Looking back on the project I could have saved some time and hassle by drilling through the pipe clamp so the threaded screw can bolt the clamp and torch body together.
The screw can then be bolted to the torch body. Not to tight as you'll crack the plastic but no so loose it will rattle loose after a few miles. If you get it just right some adjustment is possible when on the road.
Step 4: On the Bike
The lights are held on the bike with the pipe clips. Be careful to put a piece of inner-tube between the clamp and the handle bar. This will give more grip and stop them from drooping down on rough paths. It will also prevent the bars from getting scratched if that sort of thing bothers you.
The light from them is awesome and lights up the road ahead with no trouble at all. They are easily as bright as a set of spots my friend bought for about £100 and mine last a bit longer than his.
Because they are individually adjustable you can angle them to match your riding. In country cycle paths I tend to have them angled a bit closer and just a bit to either side to light up the edges of the path and spot out any bits of tree or bush that might be a hazard. On the open road I tend to have them angled to shine straight forward and give me greater visibility to motorised road users rather than light the road. Especially as I have to get across the town centre that is very busy and has zero cycle path provision.
The advantage of keeping both switches on the torch bodies is that one lamp can be switched off to preserve battery life if you get stuck out longer than anticipated.
Although the maths suggest a set of 4 AA 2000mAh batteries will last for about 3 hours experience tells me to not expect more than 1 1/2 hours. Anyway I always cycle at night with a set of fresh batteries just in-case.