# Planning riding mower conversion; need starting point



## dannysauer (Nov 21, 2010)

So, it's not a car or bike, but my old rear-engine riding mower seems like a good project to start getting my feet wet in the EV area. And it'd potentially be useful. At least, that's what I'm telling the wife. 

I've done pretty much everything with gas engine'd vehicles, rebuilding transmissions and engines, painting, welding, etc. I'm a pretty competent mechanic. I also did a couple of years of electrical/computer engineering in college prior to deciding that I liked programming more than hardware - so I have a pretty good idea of how electrical devices work. I've built some electric R/C cars but never formally competed. However, I don't know where to begin with this project. So, hopefully Internet Forums to the rescue. 

My goal is basically to just replace the existing Briggs 5HP engine with an electric motor. The gas engine is rated at 5HP, which means I'll be operating at around 4000 RPMs and only need 2-3 ft-lbs to replicate the factory performance. I'm figuring that, provided enough current capacity, an electric motor should be able to maintain speed better than the worn gas engine, and therefore handle things like tall grass better.

I'm not sure where to start, though. I obviously need a motor, but I'm not sure where to find such a thing. I need a controller, but the controllers for a full sized car are quite a bit of overkill - and one for an R/C vehicle would be undersized. I need batteries, but it seems possible that a couple of spare car batteries I have laying around might not be enough. And there are surely details like "fuel gauge" and stuff which I'm overlooking.

I'd prefer to initially stay very inexpensive as opposed to high performing, but design things so that it can be made better incrementally if this turns out to be something I'm real excited about. I'm not sure if it'd be more reasonable to run one motor for the blades and one for the wheels, or just run a single motor using the existing pulley system; two seems reasonable with one holding a target speed and a second controlling "go forward 'n backwards". If I can use the thing as essentially a go kart when it's not mowing, that'll be an ideal end state. 

Anywho, I'd very much appreciate thoughts - and I'd "appreciate more" some input on where to start finding the important parts (controller, motor, gas pedal, etc).

Thanks much in advance.


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## major (Apr 4, 2008)

dannysauer said:


> So, it's not a car or bike, but my old rear-engine riding mower seems like a good project to start getting my feet wet in the EV area. And it'd potentially be useful. At least, that's what I'm telling the wife. .......Anywho, I'd very much appreciate thoughts - and I'd "appreciate more" some input on where to start finding the important parts (controller, motor, gas pedal, etc).


Hi danny,

There have been a number of yard tractors and mowers here. But no good place to put the threads. A lot end up in the Electric Bikes sub forum. And use the search feature. You should be able to find some good examples.

Here's my yard eTractor. The thread is more about the battery, but WTH. I used an old floor sweeper motor and a Curtis controller, similar to a golf cart controller.

http://www.diyelectriccar.com/forums/showthread.php?t=44430&highlight=kokam+tractor

major


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