CT2 2-speed gearbox RC transmissions by Iliya Cerjak

RC car tuning, build it yourself transmission for use in radio controlled cars, trucks & other vehicles.


3D CAD data and/or 2D production drawings available on request.

Go here for more downloads.


CT2 1 channel controlled

1/1, 3/2 (2/3) gear ratio


CT2 – 2 Speed gearbox with clutch




Typically to tune up your RC car, either give it an overdrive gearing so it will go up to 1.5x as fast, or a 2/3x low gearing for rough terrain. Or give your RC vehicle a reverse gearing. Gives your dragster a servo controlled clutch. For heavy or underpowered vehicles it can function as a ‘pull-up’ transmission (on-the-fly shifting). The CT2 is a universal 2 speed gearbox with build in clutch. Suitable for RC cars, trucks, tanks, and other vehicles. The engines output shaft can be directly coupled to the input shaft, no need for an extra clutch (clutch is build into the transmission).


Technical details


1 bi-directional clutch controls 2 gearings. By actuating the clutch either way one selects a gear to be engaged to the drive shaft. The gears are permanently engaged to eachother, so there is no need for sychronisation and selecting the gears is on-the -fly. The clutch fork is actuated by one servo. See the animation below for of the running CT2 for an explanation. The CT2 has 2 possible configurations: Forward-Neutral-Overdrive (or low gearing), or Reverse-Neutral-Forward. See the animation of the 2 possible configurations below.


Needed materials: aluminum bar 50x8mm, Aluminum sheet 4mm, brass round 10 & 40mm, Perspex sheet 4mm and miscellaneous fasteners. (Check out the parts list below)

All gears are stock size, available for example at Sterling Instruments , RS components, Conrad or any other small drive components supplier, so are all the bearings and shafts.




Animation of the bi-directional clutch.                                    The 2 possible configurations. 


(Click on picture to see larger image)



Exploded view and assembly.                                                Outer dimensions of the assembly.




The drawing set consists out of; One assembly drawing, with detailed comprehensive exploded views and cross sections. A detailed parts list, manufacturing notes, and all drawings with the parts’ dimensions, manufacturing instructions and details.

3D CAD data and/or 2D production drawings available on request.

Go here for more downloads.

(Click on picture to see larger image)


CT2 Main assembly drawing & parts list.

CT2 build by 发表于


The comments with this CT2 were in Japanese, since i cannot read Japanese i don’t know any details.





< Go back to main page