Projects > Completed Projects

Bicyle generator


We decided to make a bicycle generator, if only to power a light bulb, for fun in the off-the-grid spirit.

First Krrrl bought a used stationary bicycle stand at BICAS:

Kyle donated his electric generator, which he built by hand:

The idea was to attach the generator to the bike stand:

Vince took apart the stationary bike stand:

And made measurements:

And then milled a coupling to attach the generator to the bike stand:

The piece was similar to a cylinder Vince had milled earlier:

Then he made wooden mounts to strengthen the connection:

The final product:

Elliot tested the bicycle generator, producing up to 12 volts:

However, after a while the generator rod slipped and came loose from the coupling.  The 2 opposing set screws did not bite strongly enough into the rod.  Therefore Elliot filed two sections of the rod flat, on opposing sides, so that the set screws had more surface area to grab onto:

Unfortunately, when we tested the bicycle generator again, the coupling came loose from the other rod (the stationary bicycle rod).  So Elliot repeated the fix, filing two opposing sections of that rod flat.

Robbie L:
Great to see this build progressing. Do you guys have any plans for a DC/DC converter to stabilize the power output of the bike? There are some Step Up/Down charge pump circuits that might work well to regulate the output.

Elliot's simple fix did not work, the coupling still slipped off the rods, and the bike would not generate electric power.

Thus David remilled the coupling, so that it would fit more snugly on the bicycle side:

Then he reseated the coupling, pushing it more deeply into the rod on the bicycle side (later he would also have to shave down the 4 wood blocks, which surrounded the coupling for added strength):

The bicycle could certainly light a few super bright blue LEDs, even if it could not power anything else.  So David made a circuit board to house 4 bright blue LEDs:

They used this circuit (not that I understand):

The reverse side, with huge capacitors:

Unfortunately the coupling slipped yet again.  We then pleaded with David to drill the aluminum rod, and press a screw all the way through both the rod and the coupling, making it impossible to slip:

We tested the bicycle generator with an electric drill, and the lights lit up, so brightly that it hurt my eyes:

However the screw spun out like a bullet. Hopefully with a longer screw and nut, all will be fixed, and a bicyclist can light up those LEDs brightly as easily as riding uphill.  We will have to test that this Saturday.

Let there be bicycle light!

It did not even take that much pedaling to power the LEDs.  In fact, we burned out the diodes.

So Robbie sacrificed a "wall wart" ... pull 2 sturdier diodes from the transformer (the 2 black components at the top):

He removed the burnt diodes; and soldered the pillaged, stronger diodes into the LED board.

The fix worked, we tested it with a bicycle. 


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