This week we’re talking about bike-powered machinery. No fabrication or welding required, tho you may find it useful.

Appropedia https://www.appropedia.org/Welcome_to_Appropedia

Prevention and Control of Distortion in Arc Welding (1945) https://www.youtube.com/watch?v=yhyekAvFc68

In this episode:

• A practical guide to turning a yard-sale bike into a power takeoff, built around an upcoming wheat thresher
• How much power you can expect and
• Where to begin the design process
• Gearing, freewheels, flip-flop hubs, steel frames, and how to tension a chain that is never perfectly round
• Belt drive with inner tubes versus chain, including the old chicken rotisserie as a gear-reduction example
• Standing the bike up, bike trainers, a sideways shaft, adult trikes, and the simple option of chaining straight off the front ring
• Multi-person setups, Appropedia, and why twenty people still only add up to a few kilowatts
• Why direct mechanical drive beats pedaling into a battery, and the kosher thresher they built years ago
• A listener question on eco-friendly building materials, plus a shop note on weld order and distortion

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Welcome to the Greenhill Forge Podcast, with Eric from the Greenhill Forge YouTube channel, and my buddy Amal, a fellow builder of many trades.

In this podcast we’ll talk about where the real world meets experiments in alternative energy, wood heating, metal fabrication, off-grid engineering and self sufficiency, so expect discussions about workshops, tools, fabrication, building, homesteading, and what it actually takes to make those dreams real.

We’ll answer a question each week, so send yours to us at https://forms.gle/zNzKTtjDnBEupLBQA

WATCH the podcast on Youtube at https://www.youtube.com/@GreenhillPod

LISTEN on all your favorite podcast platforms.

See you next week!

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CHAPTERS

0:00 Bicycle-powered equipment and the wheat thresher build

0:51 How many watts a person can actually put out

2:07 Start at the implement and work backward

3:24 Power takeoff: rear wheel or straight off the crank

4:29 Keeping the bike’s gears, freewheel vs cassette

9:46 Flip-flop hubs and a final-drive ring on the other side

11:43 Steel frame over aluminum

13:01 Derailleurs, horizontal dropouts, and chain tension

15:28 Belt drive: rim as a pulley, inner tubes as belts

18:38 Gear ratios and the chicken rotisserie

25:00 Chain tensioners and which side of the chain is loaded

27:32 Geared one-way drive vs fixed forward-and-back

31:46 Sideways shaft takeoff

34:14 Adult trikes as a ready-made shaft

37:09 Standing the bike up and locking the steering

40:24 Bike trainers as a stand and power takeoff

44:18 Simplest path: chain straight off the front chainring

46:13 Safety with chains and chainrings

47:07 Multi-person power and shared shafts

52:39 Appropedia and scaling human power

57:25 Mechanical drive vs electricity, and why solar changes the math

58:58 The kosher wheat thresher

1:02:43 Recap of the practical options

1:04:19 Flywheels, a pedal bench grinder, and line-shaft shops

1:07:10 Listener question: eco-friendly vs conventional building materials

1:17:37 Tips and tricks: weld order and distortion