Reductor electric car / gearbox

thingiverse

My son decided that his electric car going to slow and come with request to make it faster. It`s 12v electric car driven by 2 6v motors with standart reductor. Original speed up to 5 km/h, but measured on the straight only 4 km/h. So I`ve decided to change gear ratio to make it faster. Box for gears used original. Gear ratio upped from 1:110 to 1:73. Speed increased for +2 km/h. You can feel even this small difference and can follow with scooter now. Attached step file and xlsx calculator. There was some adaptations of hole diameters in step, but not described in xlsx. Xlsx fully usable to find necessary gears, speed and ratio. If you redesign on yourself - be careful with diameter of gears #WARNING higher ratio leads to lower power = more speed, less hills can take, slower goes to max speed. With current ratio-design car goes well on the hills up to 25 degrees. If car stopped on high hill it wouldn`t go by itself, need to push it once. Hills up to 15 degrees don`t make any problems.