ROWING-POWERED VIDEO GAME

Designer Jeremy Fielding builds things from scavenged materials including vacuums and treadmills and posts about them on his Youtube channel. The idea for this project – a video-game system rigged to draw its power from a rower – came after Fielding noticed his kids playing on their Nintendo Wii for several hours at a time. Here are the components he used.

Rowing machine

I removed the impeller and used a generator to replace that resistance, then used a grinder and cut-off wheel to cut a section from the mesh guard so the drive belt could fit through, and then fitted a pulley to the flywheel.

130-volt permanent magnet DC motor

I pulled the motor from a treadmill I got free. As long as it’s a permanent magnet motor, you can spin it and it will work as a generator. If you’re going to buy one, though, a dedicated generator will be more efficient.

EPEVER 20 A MPPT solar charge controller

The voltage and current coming from the motor is pretty rough. This charge controller dials the output down to a consistent 14 V that goes to the inverter.

Two SLA alarm batteries

Connected in series, these batteries help stabilise the voltage going to the inverter. They also give the Wii power when you switch the person rowing. You could use something bigger, such as a car battery, but that’s too much power – you could stop rowing for hours and keep playing. These batteries give you only about 45 seconds.

Haitral 3 000 W power inverter

Converts the DC motor’s power into AC. Inverters tend to have a very small operating range. If the power going in is even slightly outside 12 to 14 volts, it shuts off, which is why I have the charge controller and batteries. In South Africa, make sure your inverter puts out 220–230 V.

Pulleys

I salvaged one from the treadmill, bought one and split it in half, and made some others to adjust the resistance depending on the strength of the person who is rowing.

J tooth belt

Connects the flywheel to the DC motor. I attached the motor to the legs of the rowing machine on wood mounts that I made, and adjusted the position for the right belt tension.