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Thread: Gearbox reduction

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    Default Gearbox reduction

    Got a RC 4 x 4 for my grand kid but it goes too fast and I need to slow it down. Anyone modified gearing on something like this
    or is it better to get a slower revving motor if possible. The main output shaft in the middle is the drive output to front and back



    cheers thomo



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    Couldn't you just reduce he voltage?

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    Bought similar for my young nephew, and after doing a bit of homework ended up buying one with a speed limit control (learners mode) built in. That's a pretty good premise because A> it's easier that swapping cogs, and B> as the driver skill increases you don't have to recog ; just turn the motor up. It would depend on the exact model as if there's any ratio changes you can make anyway (for a lot the answer is no). but engine speed control make more sense imho

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    its a dc motor so you can cut back the volts use a mosfet best way i can see to make it easy don
    are you a self appointed hypocrite sheriff or just a nasty person

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    thanks people for some advice, it does have variable throttle, and a dial on the controller to slow it down but it is still a bit quick at the moment.
    He follows his old man and has to tow everything and thats really the problem it doesnt have enough grunt.
    The boat is not too bad but the van is a bit heavy



    I might have to start from scratch and make a 4 x 4 to

    Thanks Thomo

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    ...the bottom-most circuit using a pair of 555 timers ...whole article is a good read on the topic really.

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    What about something like these DC speed Controllers?
    I have a heap of them on different things and found them to be very reliable and take a lot more amps than their ratings. Being PWM they will reduce the speed without reducing the motor torque which if he wants to play trains with the things would be ideal.

    You could build it into the body of the car and remove the knob if you want and adjust the thing with a small screwdriver through a hole.
    There are different versions of the things in different amp ratings so you could get what ever you needed but the 10A versions are pretty cheap anyway.

    -SOME- of the Ac versions work on DC as well if you need a lot of power capacity. I have one on a solar feed for limiting DC through a heating element.








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    Quote Originally Posted by george65 View Post
    What about something like these DC speed Controllers?
    I have a heap of them on different things and found them to be very reliable and take a lot more amps than their ratings. Being PWM they will reduce the speed without reducing the motor torque which if he wants to play trains with the things would be ideal.

    You could build it into the body of the car and remove the knob if you want and adjust the thing with a small screwdriver through a hole.
    There are different versions of the things in different amp ratings so you could get what ever you needed but the 10A versions are pretty cheap anyway.

    -SOME- of the Ac versions work on DC as well if you need a lot of power capacity. I have one on a solar feed for limiting DC through a heating element.








    Thanks George I think I have one of these or similar around somewhere

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    PWM (Pulse Width Modulation) is by far the best way, as this method maintains the motor's torque, unlike voltage reduction.

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