5: Bike-powered machinery: how to take power off a bicycle

This week we’re talking about alternative alternative energy — ways to run engines and produce power that aren’t the usual solar panels or wind turbines. We go through waste vegetable oil and biodiesel, wood gasification, small-scale ethanol, methane digesters, and a few mechanical systems like wind pumps, water wheels, trompes, and Stirling engines. _______________________________ 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! _______________________________ CHAPTERS 00:00:14 Overview of alternative fuels and mechanical energy systems 00:00:58 Running older diesel engines on waste vegetable oil 00:02:02 Cleaning and filtering waste vegetable oil 00:03:30 Dual-tank veggie oil conversion with preheating and purging 00:05:07 Making biodiesel from waste oil 00:06:35 Sourcing methanol and its cost for biodiesel 00:07:50 Biodiesel compatibility with modern engines and seals 00:09:04 Mixing vegetable oil with diesel or kerosene as a simpler option 00:13:31 Using multi-fuel generators and military equipment on alternative fuels 00:16:41 Filtering methods and removing water from waste oil 00:19:04 Trade-offs between pre-processing fuel and engine complexity 00:23:54 Rebuildable injectors and choosing older mechanical diesel engines 00:27:00 Running tractors and farm equipment on vegetable oil 00:29:25 Do indirect injection diesels handle biofuels better than direct injection 00:31:00 Availability of waste vegetable oil 00:33:46 Wood gasification and producing syngas for gasoline engines 00:35:56 Small-scale ethanol production from sugar or starch crops 00:37:02 Fermentation, distillation process, and energy input vs output 00:40:34 Using solar heat to reduce energy needed for distillation 00:44:00 Dehydrating ethanol with molecular sieves for fuel use 00:46:57 Separating methanol heads and monitoring distillation temperatures 00:50:41 Ethanol yields per acre and the role of farm subsidies 00:53:35 Methane digesters that turn farm waste into burnable gas 00:56:20 Mixing manure, scraps, and fat as digester feedstock 00:57:45 Batch versus continuous digester systems for daily use 01:02:38 Mechanical windmills and water wheels for pumping and workshop power 01:05:07 Using water wheels to grind grain or run equipment 01:06:48 Trompes that use falling water to create low-pressure compressed air for forges 01:10:05 Stirling engines that run on heat differentials 01:13:55 Listener Question: Advice for starting out today 01:17:25 Tips of the Week: Trade school and trying new things

This week we're talking wood stoves. We've both heated with wood for decades, so this is the stuff we actually weigh when we're buying and using them. _______________________________ 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 In this episode: How to choose a wood stove for your house How to size a wood stove to square footage and insulation Oversized versus undersized stoves, and why running one too cool causes creosote How long to season firewood, how much wood a winter takes, and where to get it Primary heat versus an occasional fire Secondary-burn stoves versus catalytic stoves Steel versus cast iron versus soapstone What to check on a used stove, and what a new one costs Outside-air kits, indoor smoke, and carbon monoxide safety Clearances and getting a stove installed safely Listener question: How did you acquire your skills and knowledge? Weekly shop tips and tricks

This week we’re talking about building for longevity — what actually makes a house last 20 years versus 500. We compare modern American stick framing, European masonry, traditional stone, and natural building methods like cob, rammed earth, and straw bale, and why water, airtightness, climate, and skill matter more than the material itself. In this episode: Why old buildings are still standing and modern ones often aren’t How American stick framing works, and how it has changed Tight houses, moisture, mold, and the “Ziploc bag” problem HRVs, wood stoves, negative pressure, and indoor air quality Rain screens vs older tar-paper-and-siding assemblies Repairability vs 25-year wall warranties Speed, year-round building, and the trades skills gap Why buildings fail as systems, not as single products Modern European masonry and brick-as-rainscreen construction Dry-in time, cost, and US vs UK labor Brick veneer problems, window upgrades, and out-of-plumb stone walls Maintenance: masonry vs wood siding Long-lasting roofs: slate, clay tile, and standing seam Traditional stone, field stone, and lost mason knowledge Laying stone on its natural bed, and orienting wood the way it grew Natural building / “hippie building”: cob, rammed earth, straw bale, earthships, earthbags, and papercrete Thermal mass, overhangs, drainage, and climate-specific design Permitting, insurance, and hybrid builds Question of the week: the tool you most regret buying Tip of the week: spend money on tools that need to be precise

This week we’re comparing the small machines that actually get used on homesteads, hobby farms and small properties: compact tractors, skid steers, walk-behind tractors and mini excavators. We’ll go through the real jobs — clearing, grading, digging, gardens, compost, firewood, moving material — plus what to rent vs buy, implement cost and swap time, PTO vs hydraulics, fuel, maintenance, where these things get tippy or annoying, and what we’d buy first if we could only afford one. In this episode: Which machines are usually rented vs purchased Compact tractor (about 25-40 hp) as the most practical first machine Mini excavator as the strongest second machine for digging and tight garden work Why mini skid steers / dingos rarely earn their keep on a homestead Skid steer strengths (lift, attachments, speed) and weaknesses (price, fuel, visibility) Walk-behind tractors for small-scale market gardening Implement storage, used market and DIY builds Dealer vs cheap import, plus the US sub-25 hp emissions cutoff Listener question: starting welding Tips of the week

This week we’re talking about the most valuable skills that we've learned along the way, and we answer a listener question about buying tools as a beginner. _______________________________ 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!