The Culticycle is a pedal powered tractor that can cultivate, seed, spray, or pull gear for most low horsepower tasks. We talked about the first prototype almost two years ago. A new version has now been released, built around a modular tractor frame. Tim Cooke explains us how it’s built and how it works:
“The math behind the idea is nothing more than observing that a lot of the work a tractor does – shallow cultivation, seeding, flame weeding – requires very little of its available horsepower; and since these jobs are best done between 3 and 5 mph, a bike can be geared down low enough that a human can produce the necessary horsepower.
Take the cranks, seat, and handlebars from a bike and center them in a 4-wheel, lightweight, modular tractor frame: the obvious frame material is telestrut. For the front end use 20″ bike wheels and forks. You need about a foot of clearance but you want a low center of gravity and as much traction as possible: get 25 x 8 ATV tires for the rear, ideally with aluminum rims.”
“Assume you’ll pedal at 60 rpm and use a gear ratio of about 2.2 on the cranks to 3 on the differential. Now you have 25/12 x π for one revolution of the tire, x 22/30 gear ratio, x 60 rpm, x 60 minutes, divided by 5280 feet per mile = 3.3 mph. Pedal at 70 rpm and you’re at 3.8 mph. Meanwhile you’re not hunched and twisted and causing joint damage, you’re getting aerobic exercise.
And if your farm is bigger with tighter time constraints, have 2 or 3 of these machines set up specifically for those 2 or 3 row spacings that you use the most, and put the interns or volunteers on them. For instance one with a basket weeder, one with sweeps, one with finger weeders. Or fatten the front tires and throw a 12 foot aluminum ladder across the chassis and hang those big plastic harvest bins from each end, out over the beds, for lettuce harvesting: you could put 100 pounds on each end of the ladder.”
See the culticyle in action in this video.
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