Results 1 to 9 of 9

Thread: Gearbox reduction

  1. #1
    Member RedXT's Avatar
    Join Date
    Mar 2008
    Posts
    447
    Thanks
    247
    Thanked 126 Times in 70 Posts
    Rep Power
    208
    Reputation
    2004

    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



Look Here ->
  • #2
    Premium Member
    gulliver's Avatar
    Join Date
    Jan 2008
    Age
    74
    Posts
    1,102
    Thanks
    7,157
    Thanked 276 Times in 191 Posts
    Rep Power
    266
    Reputation
    3732

    Default

    Couldn't you just reduce he voltage?

  • #3
    Premium Member
    wotnot's Avatar
    Join Date
    Nov 2019
    Posts
    1,012
    Thanks
    393
    Thanked 745 Times in 434 Posts
    Rep Power
    342
    Reputation
    14910

    Default

    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

  • #4
    Premium Member
    hinekadon's Avatar
    Join Date
    Jan 2017
    Location
    still above ground level
    Posts
    1,499
    Thanks
    4,020
    Thanked 1,643 Times in 603 Posts
    Rep Power
    679
    Reputation
    29237

    Default

    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

  • The Following 2 Users Say Thank You to hinekadon For This Useful Post:

    gulliver (11-02-20),RedXT (10-02-20)

  • #5
    Member RedXT's Avatar
    Join Date
    Mar 2008
    Posts
    447
    Thanks
    247
    Thanked 126 Times in 70 Posts
    Rep Power
    208
    Reputation
    2004

    Default

    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

  • #6
    Premium Member
    wotnot's Avatar
    Join Date
    Nov 2019
    Posts
    1,012
    Thanks
    393
    Thanked 745 Times in 434 Posts
    Rep Power
    342
    Reputation
    14910

    Default

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

  • The Following User Says Thank You to wotnot For This Useful Post:

    RedXT (11-02-20)

  • #7
    Senior Member

    Join Date
    May 2018
    Posts
    2,056
    Thanks
    456
    Thanked 1,745 Times in 832 Posts
    Rep Power
    786
    Reputation
    34474

    Default

    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.








  • The Following User Says Thank You to george65 For This Useful Post:

    RedXT (11-02-20)

  • #8
    Member RedXT's Avatar
    Join Date
    Mar 2008
    Posts
    447
    Thanks
    247
    Thanked 126 Times in 70 Posts
    Rep Power
    208
    Reputation
    2004

    Default

    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

  • #9
    Premium Member

    Join Date
    Jan 2008
    Posts
    4,247
    Thanks
    5,681
    Thanked 4,081 Times in 1,735 Posts
    Rep Power
    1255
    Reputation
    47941

    Default

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

  • Bookmarks

    Posting Permissions

    • You may not post new threads
    • You may not post replies
    • You may not post attachments
    • You may not edit your posts
    •