I'm looking for an off-the-shelf 4-wheel electric-powered platform for an outdoor robot with the following characteristics:
About the size of a standard push lawnmower
Wheels around 8 to 10 inches in diameter for good ground clearance
4 wheels equal in size
Speed around 3 to 5 mph
Costs less than $500
I suspect that no such thing is available on the market, but I thought I'd ask. The closest thing I've found is a kids Power Wheels type car, but these require so much modification, it's probably easier to build one from scratch. Other than that there are the R/C trucks, but these are either too small (the 1:8 scale category) or cost $1K-$2K and up (1:6 to 1:4 scale). There is the Superdroids All Terrain Platform, but it's too small and too expensive. There is the Machine Labs line of platforms but they are in the $4K price range.