"Laziness is the Mother of Invention"

So you might ask yourself "Why build an RC Mower?". Why not? Who likes mowing the lawn?

Whoever answered "I do!" needs a swift kick in the happy-sacks.

Next to actually riding the lawn mower as you mow, what could be more fun than sitting on the porch, beer in one hand, radio transmitter in the other, mowing away merrily?

Actually, if you strapped a seat onto this one, you COULD ride it!)

A TECHNICAL OVERVIEW

So what is involved?
 

Mechanically, this thing is an electric wheelchair.
My dad scored a complete old, but serviceable chair from a dealer secondhand for a measly $150AUD. It even had a charge in the batteries and I was able to ride it out to the car to load it up.
Ask around - there's plenty of places where you could get one. I've heard of people getting them for free and shops throwing the motors and controllers in the bin!!!

I will make a frame to replace the old one, keeping the motors and associated electronic drive circuitry, batteries and wheels.
The wheelbase is extended and a common garden variety lawnmower bolted in the middle.
The lawnmower will remain complete, with the only modifications being it having its wheels and push-handle removed. This way, the mower can be easily removed if the user desires regular "push mowing" (i.e. the user is insane…).

The joystick is removed from the electronic control module and replaced with a custom interface circuit to translate the signals from the Radio Control receiver into the same signals that the joystick on the wheelchair emits, thus having complete control, as you would if you were driving the wheelchair normally. Power for this circuit is drawn from the power connector that used to supply the wheelchairs joystick.

As a side note, I really have no idea why no-one has attempted this before - it works well and it uses the wheelchairs original drive circuitry. That's a mark for simplicity and another mark for cost-saving.
 

A failsafe device is built into this unit to stop the motors immediately upon loss of transmitter signal.

A standard, low-cost 2 channel hobby Transmitter and Receiver pair are bare minimum to control the beast. Power for the receiver is taken from the custom interface circuit, eliminating the need for extra batteries.
In theory a 'deluxe' model could be made, featuring an electric start mower controlled by a 3rd or 4th channel on the RC transmitter, but one step at a time... ;).

Rough Summary of Costs:

Wheelchair - $150

Lawnmower - $200

Radio gear - $100

Electronic parts for joystick interface - $30

Total - $480

It sounds a lot, but if you look around hard enough for bargains at service places, ebay and other spots, you could actually build one for a lot less...

All in all, it's a hell of a lot cheaper than a commercially available one!

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