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Discussion Starter · #1 ·
I've started collecting the components to convert a tractor. So far I have a salvaged 2015 leaf, and have my eye on some old tractors at auction that I think might be simple conversions. Hoping to get an Oliver 88, or 1550. We own two other leaf's (2015 and 2021). It will be fun to dig into one and learn.

I just discovered this forum and am really excited to find a place to come to share the experience. As I told my wife - I found my peeps! :)
--Dave
 

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You do realize that the Leaf motor will run a tractor the size of your garage, right? Not going into the garage, but the garage itself. 200hp JD:

Tire Wheel Vehicle Tractor Sky


I get the feeling you'd get an "ummm...no" from the wife.

A tractor like an Oliver is rated around 35-40HP at 1800rpm.

If you 2:1 the Leaf motor shaft speed, run it at 4000 rpm, you should be able to get by with a 200V cell stack...

You'll need to keep the dual clutch if you run the pto..
 

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You do realize that the Leaf motor will run a tractor the size of your garage, right? Not going into the garage, but the garage itself. 200hp JD:

View attachment 127697

I get the feeling you'd get an "ummm...no" from the wife.

A tractor like an Oliver is rated around 35-40HP at 1800rpm.

If you 2:1 the Leaf motor shaft speed, run it at 4000 rpm, you should be able to get by with a 200V cell stack...

You'll need to keep the dual clutch if you run the pto..
Wanna collaborate on converting that ? :D
 

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Discussion Starter · #7 ·
Tractor size has been a big debate, on one hand I realize the leaf motor could do more, but I really don't want to tackle something big - garage size as you say is one limiter :) I also wanted something not running so it's cheep and I don't feel like I'm destroyed something useful if it doesn't work out. Thus looking for something old and mid-size. Large enough to be useful for making hay, and large enough to hold the batteries.

What I like about the Oliver design is the engine is not part of the structure/frame. And the transmission shafts (PTO and drive) are exposed. PTO shaft runs inside the drive shaft/pipe. I've got an idea for a clutch design, and hope to sketch it up and post it.

Reading some of the info here, I realize the RPM of the leaf motor will need to be geared down as you say - like by an order 2 to 4. I was thinking of just using the leaf transmission - but that would be too slow - I recall someone saying it's like a1:8 ratio. And of course it has the differential with 2 shafts... and the idea came to mind - if you hold one shaft stationary, the other shaft will spin at 2x the rate. Thus cutting the final ratio to around 1:4... However I'm concerned that differential isn't designed for that amount of use/abuse. Any thoughts?

My goal is to try to use as much as the OEM parts off the leaf as possible. motor, batteries, charger, controller, etc. So staying with the original battery size/voltage I assume would be needed to keep everything happy. Of course I would have to pull the battery pack apart and reconfigure it to the shape needed.

Thanks for the encouraging replies, my wife did agree - that 200hp JD would be a bit much :)
 

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Reading some of the info here, I realize the RPM of the leaf motor will need to be geared down as you say - like by an order 2 to 4. I was thinking of just using the leaf transmission - but that would be too slow - I recall someone saying it's like a1:8 ratio. And of course it has the differential with 2 shafts... and the idea came to mind - if you hold one shaft stationary, the other shaft will spin at 2x the rate. Thus cutting the final ratio to around 1:4... However I'm concerned that differential isn't designed for that amount of use/abuse. Any thoughts?
Uh no, holding one side of the diff stationary won’t reduce the rpm of the other side, it just transfers the torque 100% to the other side.
The rpm will be the exact same.
Your also distributing the torque through the spider gears of the open diff, which are not designed for that, and will most likely fail prematurely.
Also lots of drive train energy loss, not very efficient!
 

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"and the idea came to mind - if you hold one shaft stationary, the other shaft will spin at 2x the rate. Thus cutting the final ratio to around 1:4..."

This is brilliant. 🤦‍♂️ Wow, why didn't I think of that, because it DOES speed up the other axle's RPM by 2x when you fix one axle stationary to the case as anyone who's gotten stuck in the snow without a diff lock can attest.

For the Oliver, I would worry more about busting the Oliver driveline with the available HP (as long as you limit the inverter, you should be fine) than the Leaf's gearbox. You're going through massive gear reduction from the Leaf from there to the tires and you're only pushing 35-40hp out.

Nice...
 

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Uh no, holding one side of the diff stationary won’t reduce the rpm of the other side, it just transfers the torque 100% to the other side.
The rpm will be the exact same.
No, he had it right. The average of the two differential output speeds is the input speed. If you lock one output stationary, the other rotates at double speed.

Your also distributing the torque through the spider gears of the open diff, which are not designed for that, and will most likely fail prematurely.
But I agree - don't use a diff this way, as the spider gears and their bearings are not designed for it.
 

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Discussion Starter · #14 ·
Making some (mental) progress on this project - I plan to bid on a 1964 Oliver 1800 tractor (70hp). A step up from what I was originally thinking - up for auction Feb 23rd - it's not currently running so hopefully it goes for a reasonable price.

I'll probably not use the hydro-power box (2 speed gearbox connected to the bell housing) and use the Leaf gearbox with the spider gears welded such that I can use one side of the drive shaft running a 5-V-belt pulley to increase the RPM output using whatever ratio makes sense - thinking a 13" driving a 6" pulley might work.

The benefit of the pulley approach is I can easily change the ratio if I don't like it. Hoping to use the tractor's flywheel, clutch pressure plate attached to final pulley shaft.

I have an old New Holland self-propelled baler with a ford inline-6 that uses 5-Vbelts off the engine to run the thing, so I figured it may work here as well.
 

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I'll probably not use the hydro-power box (2 speed gearbox connected to the bell housing) and use the Leaf gearbox with the spider gears welded such that I can use one side of the drive shaft running a 5-V-belt pulley to increase the RPM output using whatever ratio makes sense - thinking a 13" driving a 6" pulley might work.
Have you considered a single toothed belt instead of a set of V-belts? The only things that you can guarantee about a set of V-belts are that they'll all be at different tensions and that one will fail before the others. ;)
 

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Discussion Starter · #17 ·
Have you considered a single toothed belt instead of a set of V-belts? The only things that you can guarantee about a set of V-belts are that they'll all be at different tensions and that one will fail before the others. ;)
My thinking on using the V-belts is that if something goes wrong I want it to slip instead of bust the tractor drive. That was more the case when I was thinking of using a smaller tractor, maybe not so much with the one I'm thinking of now. Haven't had an issue with them on my 50 year old baler - probably has the original belts on it.
 

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My thinking on using the V-belts is that if something goes wrong I want it to slip instead of bust the tractor drive. That was more the case when I was thinking of using a smaller tractor, maybe not so much with the one I'm thinking of now.
The motor shouldn't be able to bust the tractor, if suitably sized. EV conversions don't normally include any component as a deliberate torque limiting feature.

Haven't had an issue with them on my 50 year old baler - probably has the original belts on it.
Yes, if the torque requirement is low enough for the size of the belts, they can stumble their way through many years. :) More highly stressed installations are less fun.
 

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My thinking on using the V-belts is that if something goes wrong I want it to slip instead of bust the tractor drive.
That's ICE thinking.

You can very easily limit motor torque output with the inverter controls. Belts shouldn't slip or you lose the entire point of efficient propulsion.

Unlike a car, for a tractor you need SPEED, not torque, -based control if you have any hope of running the PTO without pulling your hair out.
 
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