Instructions available. A 4-speed sequential transmission controlled by a custom stepper motor.
About this creation
This is the sequential transmission and stepper motor combination that I used in my Hummer H2 SUT Style Truck . The stepper motor is as accurate as the Lego pieces themselves, and when used with the 4-speed sequential transmission mechanism shown with it in the images below, it forms a relatively small 4-speed sequential transmission with approximately a 95% switching accuracy.
Several important things should be noted:
- Having the transmission driving rings located on non-ribbed axle connectors is not a mistake; they work better that way. If building out of the instructions, make sure that the transmission driving ring slides smoothly on the axle connector. If there is considerable resistance, take the driving ring off, rotate it by 90 degrees, and put it back onto the axle connector.
- Take special notice of the elastic in the photos, as it has to be built directly into the stepper motor. The elastic should be strong enough that it restricts the square’s movement to only 4 positions.
- Green marks the inputs of the stepper motor and transmission, red marks the outputs.
- The stepper motor can be controlled by any motor, preferably an M motor, E motor, 71427, 43362, or 47154 at a 5:1 gear reduction or lower.
Great work. It looks like a more simple but compact as well set up of Jaco4. It appears that if you keep the motor running it will keep shifting the gearbox infinitely.
I'm busy with these systems as well, hopefully to match the quality of yours. Keep it up!