2-speed Sliding Gear Transmission
A compact 2-speed transmission design focused on durability and smooth shifting. Free building instructions available.
Having experienced a physical damage to a LEGO clutch gear from a LEGO transmission driving ring in my Pinzgauer 712 T 6×6 model, I have tried to find a solution for a durable transmission that doesn’t use clutch gears or driving rings and is still capable of shifting smoothly without jamming. I’ve tested a prototype of such a transmission in my Tatra 813 8×8 model, and it worked, but it required excessive force to shift and it used two PF XL motors for drive, which is more than most models need.
I’ve taken the basic concept from the Tatra model and rebuilt it around two PF L motors, with a selection of gears designed to make shifting stress-free and smooth. The resulting transmission is highly durable, has a practical form factor with all motors located above the driveshaft (which comes out in front and back, making it suitable for AWD models and for models with limited wheelbase) and is very easily shifted thanks to the use of a slipping clutch. The default gear ratios it provides are 3:1 and 1.67:1, but these can be easily adjusted since the gears that affect the ratios are conveniently located between the beams below the main assembly.
The presented design needs, of course, to be properly braced inside the chassis to be able to handle some serious torque.
Free building instructions are available on the Downloads page.
