Feb 11th: Finishing almost ready, new pics to be added in a few days. The cold weather causes the delay.
Thinking for quite a while about a sturdy and cool bike light, I found a great motorcycle head light at a 2nd hand market.
My initial requirements for the lights: (After installing the fixture, the worsest engineering problem occurred: intermittent failure. It required lots of changes, which are added in ITALICS). This is a real life example of KISS (keep it simple, stupid)
- Bright, preferably illuminated with LEDs.
- Running on === 6 V, since my bike has a hub dynamo.
- Good functionality, but possibility to switch to additional subtle and less subtle effects.
- Reasonably theft and vandal proof
My requirements for the handle bars:
- Light has to fit in between the vertical parts.
- Ergonomic design
Materials for the light:
- 'camping light'
- dynamo: hub type.
- Motorcycle head light from 2nd hand market.
- wiring, switches and circuitry to switch on and transform to 4.6 and 2.5 V
- nuts & bolts, glue, etc.
Materials for the handle bars:
- 22mm galvanized pipe
- 2 Tees, .
Tools: standard tools, a pipe bender and torch with soldering stuff. Pipe benders usually can be rented. Soldering tools for the circuit.
Step 1: The Handle Bars
I am 2 m (6'6") tall. A few years ago, I obtained a 2nd hand 7 speed hub (Shimano Nexus) bike. It was a bit too sporty for me: I need a strong bike, with lots of transport capabilities, able to carry a good load, and tow a trailer... Tall people need to modify everything, and one of the things to be changed were the handle bars.
The first mod was to attach some handlebar extensions. The low position makes my hands numb and my neck stiff, as I have to point my head up all the time.
This stuff is normally used to enable bending over even more than the pitifully low standard position of handlebars allows (as many folks are craving to get an even better view of the asphalt being traversed), but in my case, they were quite helpful in allowing a more upright position.
It is nice stuff... sandblasted aluminum, with a good feel... in summer..., pipe insulation is needed in winter....
Finally, my handlebars broke in two (forgot to reattach the bracket of the front brake :o ).
The new handle bar design is much higher, so new, longer cables had to be bought to fit.
Central heating (thin steel pipe, 22 mm, or conduit...) galvanized pipe was used. Nothing was bought, as most large home renovations involve discarding loads of perfectly good pipe... (anyway, pipe is not expensive).
Tee joints were used for the corners. Why not elbows? On both sides, a yellow LED shines trough...
It can be used as is, but brass- zinc used together invites corrosion. A (black) paint finish slows this down, and looks cool. Yearly touch-ups are probably a good idea.
The light fixture needs to fit smugly between the vertical elements of the handle bars. It is fixed by 2 M8 bolts.
The transport carrier is made out of a handcart: www.instructables.com/id/Bicycle_Front_Transport_Carrier/
Step 2: Electronics
A hub dynamo provides a relatively constant, 6V DC voltage.
-After intermittent failure (was it the snow/ salt, bad soldering, components ??), the hub dynamo proved to be the bad element, giving off a wildly fluctuating and flickering voltage, but the little circuit board I made showed quite some corrosion as well... The fluctuations also interfered with the electronic circuitry of the camping light.
The 1.50 Euro 'camping light', is designed to take 3 AA batteries... = 4.5 V. It has its own circuit board and switch, 2 settings: 11 or all, 24 LEDs on.
The switch was desoldered from this board, to be extended.
The circuit board with diodes, to take care of dropping the 6V to appropriate values was cut out. Instead, a 3 AA battery holder was placed to provide power. One diode drops the voltage to light up some green and orange LEDs.
Switches were taken from very nice looking 99c mini flashlights. The switches are on/off type. This does not work for the main headlight, which needs a switch like the ones in computers.
These switches look great but are absolutely not weather proof. After one month they look rusty from the inside, and 2 of them are stuck. Since the holes for them are already drilled, I leave them in place, but they only have a decorative purpose now.
Step 3: The Fixture
This motorcycle fixture is large enough to store both light and circuitry. The large reflector is not functional as is: while the original halogen bulb shines everywhere but forward, making the most of the reflector, the LEDs only shine forward in a narrow beam.
It has 2 settings: Only the center 11 LEDs or all 24 LEDs. The beam of the center LEDs shines on a section of a plastic Christmas ball hot-glued to the inside of the fixture glass. This reflects the light to the reflector.
3 switches are put on top of the fixture. The switch housings have a M12 x 1mm thread. Holes of 10 mm were drilled, and very carefully, the size of the holes was filed to the proper size. The switches themselves were used to squeeze the threading into the plastic of the fixture.
However, after just a little bad weather, they got stuck, and looked very corroded from the inside. Since the holes are already made, they are left in place, just for show (and to plug the holes).
Step 4: LED Attachments
Inside the front light, 3 green LEDs are glued between the white LEDs. They are always weakly on, as long as power is connected. (it was meant to be wired in series with a capacitor to stay on while waiting for traffic lights while the hub dynamo was not running).
2 orange/ yellow LEDs stick out from the tees, in their original keyhanger 'lightbulb' enclosure. They are connected to the battery holder.
Step 5: Finishing
The light is now battery powered. I get lots of approval, especially kids really like it. The handle bars and transport carrier got a fresh coat of black paint.
Eventually, I ended up using the body of a E 1.49 flashlight (3X AAA battery holder and a good waterproof switch, soldered to a connector from a huge old copier. The side lights are fed by the battery holder as well. As I had many white LEDs from the flashlights and the original orange LEDs fried going downhill, white LEDs with some orange plastic wrapped around it were used.