4 Speed Manual Gearbox

thingiverse

This is a fully functional gearbox, boasting four speeds: three forward and one reverse. Check out this video to see it in action: https://www.youtube.com/watch?v=aXXH8JMoDXg. To assemble your gearbox, you'll need to print each file once for the duplicate parts. If there are any missing files, feel free to contact me - I encountered issues uploading them initially. ### Additional Hardware: * The shafts are solid 4mm brass rods. + Two main shafts measure 185mm in length. + One shifter shaft measures 90mm. + Another shifter shaft measures 155mm. + A reverse gear shaft measures 70mm. * The design is held together with M3 screws of varying lengths: + Fourteen screws are 16mm long. + Nine screws are 20mm long. + Eight screws are 25mm long. In most cases, you can use longer screws if the correct length isn't available. ### Motor and Coupler: * The motor is a typical 90° geared dc motor found on eBay or AliExpress. * I used one rated at 19 RPM, 6v, but it could be slightly faster. The coupler for the motor is a flexible coupler that transitions from 6mm to 4mm. ### Assembly: To attach the gears and shifter mechanism to the shafts, roughen up the surface of each shaft. Then, use CA-glue to secure them in place. All gears on the input shaft and the two central gears on the output shaft are fixed. The others move along their respective shafts. I applied Silicon Grease to all moving parts that come into contact with the shafts.