Q: High resolution servo operation

I have taken a childs ride'em "big Foot" truck, (the ones that you would get at Toys 'r' us and so forth) and converted it to remote control using cheap
transmitter -receivers from another toy. Very successful. Now I wish to remove the electric motor and replace it with a gas engine. I was wondering how (rather inexpensively again) would I control the throttle on the engine with a servo, where I can micro adjust it's rotation of the servo to increase or decrease the throttle action as needed.
TIA
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wrote:

run the servo bellcrank to the throttle with a cable, it's easier than trying to connect directly to the throttle.
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I bet if you're looking for speed, you don't even need a gas engine. Those things are geared to haul the weight of a small kid. If you simply geared it up more you could use the existing powertrain and get a hell of a lot more speed out of it since you wouldn't have to worry about a 5 year old's weight in it.
I can tell you right now that if you're having issues throttling an engine with a servo, you're going to REALLY have problems beefing up the drivetrain. I'd guess that even a weedwhacker engine would strip the gears out in about 5 minutes if that. Also is the problem that those things don't have a differential gear. They have two independent motors and two gear reductions. I don't know how well you want it to drive - maybe a locked shaft would be OK for you.
I say abandon the KiddeRidem' idea (unless you're using it to drive in front if yuppies in their SUV's speeding down your street) and just build a kick-ass giant scale R/C car out of go-kart components.
Andy
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What is better, is to go with the Quarter Scale RC Racing Cars and Trucks. Now your talking about some fast RC car speeds. Here is a good starting point http://www.quarterscalemtrsports.com / Unfortunately the plastic Kiddie cars weren't really meant to last for very long. The plastic gears and stuff will be quickly destroyed with a gas engine.

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