Moving target

I need somebody who knows something about electronics, specifically model radio control and automotive starter motors (and the like) to chime in.

We're thinking of building something as a moving target for our local shooting range. It would mimic the motion of a person but not move any faster than about walking speed.

What we have in mind is a couple of car batteries driving a starter motor, driving two wheels (say, the fronts off a riding mower--12" diameter max) on a small (roughly 2' x 2' square) frame. The other two wheels (the rear ones) would be the steering and probably smaller in diameter. The whole thing would be controlled by radio control (possibly something from a R/C car) with only steering and throttle. It would have to be relatively heavy (say, 100 lb max) including the batteries to remain stable and have a fairly heavy steel plate in the front and sides to protect from handgun bullet strikes, but we don't want the thing to be so heavy you can't pick it up to put it in the back of the truck. We'd use light wooden supports from which to hang cardboard targets. Optimally we'd like the ability to hook up a "disconnect" to the power if the shooter hits a critical steel plate target (center of mass, etc.)

The only wrinkle that's giving me pause is having a servo motor strong enough to steer it. Windshield wiper motor, perhaps?

Thoughts?

I'm not sure but I think you will burn up the starter motor trying to use it for constant running.

But I can tell you that my sons 12v powerwheel will move around just fine with around 165 lbs sitting on it, so maybe grab the drivetrain from that. It uses 2 550 size motors each with its own gearbox...on second thought why not just get a powerwheels jeep and armor it up?

For steering I would start with 1/4 scale or giant scale servos, just attach it to the seat and run a linkage to the steering wheel. If you need more power you can use a dual servo set up.

Most(if not all) 12v powerwheels have a 2 speed + reverse setup and if its not fast enough, its easy to add a "turbo" button for more speed.

The daughter (when younger) kept wanting to be pushed around on one of those push-car toys. With #2 coming up to riding-toy age, I keep threatening to R/C a PowerWheels so I don't have to walk up and down the driveway all afternoon.

Or am I just being lazy?

One of the powerwheels ferrari type things you find on ebay is already remote controlled.

I'll ditto the power wheels setup. Lightweight, rechargeable battery, carries your intended payload easily, runs stock at your desired speed. Just find a way to control throttle and steering, and you're all set, and cheaply.

jeffmx5 wrote: The daughter (when younger) kept wanting to be pushed around on one of those push-car toys. With #2 coming up to riding-toy age, I keep threatening to R/C a PowerWheels so I don't have to walk up and down the driveway all afternoon. Or am I just being lazy?

one could argue that you are gaining wisdom in your old age

Home Depot...messicans...something something.

Take a powerwheel armor it, put a mannequin on it, pound a stake in the ground, tie a rope to the stake and the powerwheel, turn it on and it goes in a circle. Probably not ideal but simple.

Maybe get some deathrow inmates to do it instead?