While my zero turn mower project
patiently waits for me to find a perfect pair of worm reducers I have started on a much more practical project that enjoys much broader support here on our farm.
I am converting our Hefty-G cultivating tractor into a battery-EV from it's original gas-powered config, mostly so the damn thing will work when we need it to rather than pulling untimely stunts like it did most of last year. It's a pretty unusual tractor and not too terribly common so hopefully some of you will get a kick out of it.
The Hefty-G is a late 1970s copy/homage to the 1950s era Allis Chalmers model G which was, I think, the first small cultivating tractor in North America to move the engine aft of the operator, thus freeing up the space between front and rear axles for "belly-mounted" tools for precision work like seeding, weeding, hilling, etc. A brilliant re-think of the standard tractor configuration aimed primarily at vegetable growers before the advent of chemical weed control.
Fast forward 50+ years and these old tractors are being dug out of barns and put back into service on organic vegetable farms like ours where they continue to ably perform the tasks they were designed for. Well, with the possible exceptions of starting reliably and running smoothly without constant breakdowns. Luckily these problems are all easily resolved by throwing out the ICE and replacing with a suitable electric motor.
The Hefty-G is perhaps the easiest conversion project anyone could ever find. It was built out of pieces, almost zero integration, and everything just bolts together. They were turned out by a smallish concern in Wisconsin – the Holtan Axle Co. or Haxco – which built gearboxes and diffs and decided to try their hand at copying and updating the venerable Allis G. They did a great job in many respects but the rebadged Renault engine supplied by Continental Teledyne hasn't aged gracefully or made any friends at our farm of late. Nor are parts available. I guess I can thank the little bugger for motivating me to extract it this winter rather than trying to wait another year.
Okay. The build is pretty simple as you'll see in the pics. The gas engine shaft-drives the clutch and tranny and though it's not quite bolt-on easy I can't see how it's going to be too challenging to mount the electric motor in almost exactly the same spot.
The motor I found was rebuilt and shelved. Looks super clean and flawless and wasn't too expensive. AMD 203-02-4004 badged as Raymond, pulled from a lift, probably a standup 3-wheeler. It's a sepex/shunt motor which is fine because I found a big 600A General Electric sepex controller at a fair price on eBay. I may not even reverse the motor so it being sepex is not necessary but the price was right so there we are.
The AMD motor is 8" diameter, approx 14" long and is similar to one whic forum member Boekel used in a boat but now I can't find the thread. I'm planning to run it at 48V using a battery bank of Chevy Volt modules, probably 4P12S. I don't need tons of runtime or load as the tractor is primarily used for weeding, a couple hours at a time, and it's geared-down like crazy. It is not a tillage tractor and was ably powered by a wheezy old 20-odd HP gas engine with all of 800cc of displacement and a centrifugal governor. Good riddance to that particular piece of tech
The motor also has the advantage of having a tailshaft that should let me keep my original open center hydraulics with no modification (pump shown in mockup pics). I think I'll have two throttle pots in parallel if that's feasible, one foot and one hand throttle. I'll keep the clutch so that when I want to stop the tractor but keep spinning the pump for hydraulic flow I'll just depress the clutch with my left foot and spin up the motor with my right.
I'll post more photos and questions as I progress. There's a photo album here on Facebook
but here are a few and a link to a walkaround
video on youtube here.
Don't be confused by the cylinder cradle and propane hoses on the right side fender. The tractor was not propane powered. That gear is all part of the flamethrower... sorry, the "flame weeder" mounted at the very front of the machine. It's a totally valid and accepted technique for killing certain weeds at certain times, even in organic systems... honest
It's fun for lighting campfires too flame weeder demo on youtube
Suggestions and words of wisdom are always welcome.
Anyone ever set up one of these GE IC3645 controllers? Mine is IC3645SR4W606N6. Should I worry about the controller map being properly suited to this particular motor? I'll have to figure out programming for the controller eventually.