experienced advice I need (tractor)

[JackR]

Hi

I am a beginner please be nice

So basically I want to buy an cheap old diesel tractor and rebuild it to an EV or EA Electric Agricultural, lol.
I need some experienced advice and recommendations/opinions. So here are my questions and concerns

The main objective is to have a lot of torque at low speed < 1km/h or less because for some planting applications our current Massy Fergusson is to fast even at the lowest speed. EV would be good because its silent give a lot of torque even at lower RPM, we could use our solar overproduction for the tractor and generally less maintenance compared to old diesel and I feel that the battery technologies are good enough now.

Q1. What are good easily hackable EV small (+/- 10 to 30 Kw is fine) motors with a lot of torque at roughly 1000 to 1700 rpm, I think I would need a reduction gear to reduce car EV motor to high torque low speed. I want low tech as possible if possible low voltage around 72V to 220V.
(available in garages or Ebay in EU)

Q2. Generally hackable controller/BMS so that pretty much every aspect is readable or controllable somehow. Mainly because I want to integrate it with a opensource GPS system called AGopenGPS for automatic GPS steering.

Q3. I want to avoid proprietary locked down software because I want to do this to save money all in aiming for +/- 2 to 5k euro. Or less

my background: I have high school degree on electronics with very basic mechanical knowledge and currently studying for my bachelors in Electronics and IT.

any opinions or recommendations welcome.

[ianlighting]

Have you looked at this tractor build? Might give you some ideas…

viewtopic.php?t=2179

There’s an important point with old tractors, and it’s mentioned in the build above, that many makes had the engine as a structural piece. They often don’t have a chassis that you just swap out engine for motor, so you need to consider that.

Lots of people start with Leaf motors because they’re cheap and relatively plentiful. But they are designed for 350+V, don’t know if you can make them work at your preferred voltage.

[ianlighting]

Or at the other end of the scale check out Benjamin Nelson on YouTube. He’s doing a remote controlled lawn mower project at the moment.

[JackR]

Thanks for the reference to this project looks very interesting and similar to what I need.
I will deeply look into this!
As for the structural engine, I will need to take this into account when looking for a old used or busted tractor.

appreciate taking the time to reply

[LRBen]

any opinions or recommendations welcome.

Sorry I only just noticed this thread.

I think once you get past 65v and into official HV territory you might and well go full 96s voltage as it makes it easier to find cheap compatible components. Leafs and Outlander motors are decent, cheap and easy to control. Don't worry about the speeds as you can limit the RPM. With my Leaf motor in the tractor I limit it to around 1500rpm or 2000rpm depending on if im doing PTO or road work. It still has more torque than the original diesel engine has so there is no need to gear it down.

Zombie is a great controller for any conversion. Can't recommend it enough. I was originally thinking about adding autosteer so that might still be a side project I look into in the future.

I did choose the Leyland specifically for the non structural engine, a few others brands did that as well, such as Zetor and Belarus, some David Browns are similar as well. But adding in your own structural replacement isn't impossible, it's quite common on engine swapped tractors. Just adds extra time, work and expense.

In terms of cost, I have spent more in restoration costs than conversion costs. In the UK at least it is not worth getting a run down tractor as the costs of restoring it are usually more than what it would have cost you to get one in a good condition to begin with. I would say my conversion costs are on the high end of what you have budgeted.

Any questions feel free to message me or post them here for future reference.

[jrbe]

I second the higher voltage if you're going above 60v.

I wonder if the Hyundai HSG (hybrid starter generator) would work well for something like this. It's water cooled and is belt drive so you could gear it with the serpentine belt to whatever ratio you need. It has a really beefy tensioner. I think people are using them at 30kw but not sure how long they can do that with good cooling.

I suppose you could use 2 HSGs if needed and something like a Prius inverter but without positioning. Not sure how no positioning would go. There should be enough slack in the system / enough of a gear reduction that it wouldn't be too big of a deal, I think..