Tractor
incoherency.co.uk
incoherency.co.uk
I ripped the tractor down the the frame and removed most parts. Got $40 Ryobi walk behind mower motors (42V which is really 36V), some scooter controllers, and pulleys. I used two scooter Li ion batteries but I should have just gotten three large lead acid 12V batteries for more capacity. Still, I can mow for an hour or so and get almost an acre done which includes some hills per charge. It took about 8 total days to build and about $800.
The way I set it up is that I have one motor drive the wheels and two more motors on the deck directly driving the blades. The belt system the ICE motor version had was insanely inefficient. This system has like 20% of the power but mowed better and is way more reliable. For $150 I could get a solar array and controller to charge the batteries and never pay for anything but belt and blade replacements for life.
The hardest part of the build was lining up the mounting of the drive motor and wiring up all the safety systems (brake sensor, seat sensor, etc). The kicker is that this is a way better product than what I can buy commercially unless I get into the $5k+ territory and is completely user serviceable. No part here is more than $100 and they all readily available. The tractor has enough torque to push my huge picnic table around while I am riding it. I might try seeing if I can plow snow with it next winter.
Granted, I understand that the purpose of a project like this isn't just in the end result. Depends what crafts you want to practice and what's just necessary work around them. There's still quite a bit of fun project left in converting an existing mower to electric and refinishing it to look more like a classic tractor.
Though the goal was a kids toy, and those mowers are too large for that use.
Stuff goes straight to permanent memory at that age so by giving them a "real" tractor there's a lot of potential to learn good lifelong lessons prompt them to ask the kind of questions that result in good teaching.
They're constantly sold dirt cheap in my area with very minor problems, like old gas. People don't know how to fix it, so they buy a new one and sell the old.
I bought four working mowers. $500, $250, $220, and $200. One was missing a deck, one was running rough. Otherwise complete.
They're all craftsman, one vintage from the 80s.
We use one to mow, one to move the trailer, the old one mows but it mostly sits, and the last was a gift for my wonderful neighbors who are old and were still using a walk behind.
I'm in New Zealand and we have a number of deaths every year from quad-bikes on farms. Often children. They are being careful but quads on slopes are dangerous.
I'd rather have my kid ingrained with the idea that electricity is the future even if it's an amazing achievement to be able to tame explosions to move around
Other interesting Story about tractors:
"In the heartland of American agriculture, a quiet revolution is underway. Farmers, long frustrated by the high costs and restrictive repair policies of leading tractor manufacturers like John Deere, are increasingly turning to simpler, more affordable alternatives from an unlikely source: Belarus. These rugged, no-frills machines from Minsk Tractor Works (MTZ) are gaining traction not just for their price tag, but for their deliberate avoidance of the complex electronics and subscription models that have become the bane of modern farming."
source: I'm a terrible amateur welder
My conception was that we're adding power by increasing the voltage and we're stacking up material by adding wire, so to get good penetration on thick material I want lots of voltage and not much wire feed.
But actually it turns out that you make it hotter by increasing the wire feed speed.
I don't really see why, but at least now I know.
Here's a more recent weld: https://img.incoherency.co.uk/6464 - still not great but not nearly as bad.
I'm learning with you.. the polarity was fresh in my mind because I recently got half way through a project with little bb's splattering everywhere before a friend with more knowledge asked if I had recently changed wire.
Welding seems to be a lot like baking; It is very deterministic in a sealed environment and the parameters are well understood, but in practice the experts rely heavily on feel and experience more akin to an artist.
Love the spirit of the build, though, and it's a case where weld cleanliness doesn't really matter, so, more power to him.
Fun stuff!
This build in the article reminds me of the one I owned for a while, was a lot of fun. Hope the kid has as much fun with theirs as I had with mine.
Is this “best” project I’ve seen? In terms of tech,quality,etc No. Neither are mine. This guy built a really fun project for his kids.
I love this. As AI slop gets increased, I hope that content like this starts to get filtered up to the world.
I also learned about a web-ring from his website. I think this is an artifact from the early Internet. I hope this gets more popular for website discovery reasons
I thoroughly enjoyed it. No BS, no ads, no sale pitch, no AI, no pretending, nothing. Just a stranger sharing with the world a project he built at home.
Those picture of the welds are inspiring. It is as honest as it gets. Loved it.
Thank you.
What the heck is it doing on HN's front page?
Got two questions: 1. How fast it can ride ? If I good estimate (based on max 2750 RPMs for electric motor MY1016 350W 36V, gear ratio ~100:1 and height of rear wheel ~0.5m) it should got about 0.8 m/sec. So really safe for kids and dad :)
2. How long does the battery last ?
I don't know how long the battery lasts, we have never driven it for long enough to flatten the battery.
While I was building it I used it for about an hour doing several laps of dragging a "trailer" full of rubble from the top of the garden to the bottom (the easy direction - empty load on the way back up) and it became noticeably slower towards the end but still got me up the hill. So I'd say it lasts over an hour.
It's much cheaper than the laser stuff. It gets expensive if you want to use gas, but if you stick to flux-core you don't have to.
You might be amazed at how little power you can get away with in an actual tractor. 20HP is close to the upper limit of practicality unless you are running a large commercial operation.
Literally children die from riding on such things.
Keep your children safe a well and alive, dont let them on anything like this or near one being driven by someone else.
I'm a farmer, I know what working vehicles are subjected to over time, and I know that when plywood gets wet, it swells, warps differentially, splits at its layer boundaries, and starts to twist. Tractors are for driving over land that is often at least damp. This is not a recipe for durability.