3+R transmission (regular and shifterless)
A transmission concept in two versions: regular and shifterless, which is shifted and driven using the same single motor.
I have developed a modification of my 4-speed sequential transmission which replaces the 4th gear with a reverse gear. The transmission is 1 stud longer in this version, and just to demonstrate various possibilities I’ve made instructions on how to build it into Technic bricks and with a stepper included. The downside of this design is that the reverse gear is the fastest, but any other solution would increase the size of the transmission.
Next, seeing as with a transmission that includes a reverse gear there is no need to reverse the drive motor, I have developed a variant that uses single motor for driving and shifting. This variant only requires one motor: when the motor is driving in one direction it drives the transmission, and when it’s driving in opposite direction it shifts the transmission. This potentially frees up a single remote control channel, but at the cost of requiring to stop in order to shift the transmission. There is also another issue – the ratchet which allows “selecting” a function depending on the direction of the motor, has a limit of stress it can handle. Simply put, if this variant of the transmission is stressed to much, it won’t be able to drive nor to shift.
Building instructions available here: sariel.pl/downloads/
Videos:
