The MK4 features our new 1.5" width Billet Wheel. Because of the 50% increase of width, greater tread life and slightly better traction can be expected. To accommodate the new wheel the MK4 uses our new 2nd Generation bevel gear set.
Despite it being one of the most compact and lightweight modules available, the MK4 module does not compromise on robustness. MK4 modules use all steel gears for superior wear resistance. Under typical use, the modules will be able to handle multiple seasons of robotics competition. In order to keep weight to a minimum, the steel gears are pocketed.
Like the MK3, the MK4 uses a centrally located steering encoder to directly measure steering angle without the use of gears. This eliminates encoder backlash and reduces part count. The module is specifically designed for user favorite CTRE CANcoder.
The MK4 module ships unassembled and does not include the motors or encoder. The 1.5" width billet wheel is included.
REV Robotics NEO motors or Vex Robotics Falcon 500 motors are recommended for the MK4 module. The MK4 is also compatible with VersaPlanetary gearboxes with CIM output shafts. CIM motors are not compatible with the MK4 due to their larger diameter. The MK4 module is available with either NEO 8mm bore pinion gears, or Falcon 500 spline bore pinion gears.
The steering gear ratio of the MK4 is 12.8:1 The MK4 is available in 4 different drive gear ratios. The table below shows the drive gear ratios and free speeds with NEO and Falcon 500 motors. L1 and L2 ratios are the most popular ratios and are suitable for standard full weight competition robots. The L3 ratio is more aggressive and is recommended for light weight robots. The L4 ratio is very aggressive and is only recommended for very light weight mini bots. 

 
The module easily mounts to common 2X1 frame material. The module typically mounts on top of the robot chassis, however, there is also clearance to mount the chassis on top of the module to maximize ground clearance.
The MK4 module design requires the length of both motor shafts to be reduced by about 0.25in. Alternatively, motor spacers can be used to eliminate the need to cut the motor shafts.
Weight:
MK4 module with NEO motors - 4.9 pounds
MK4 module with Falcon 500 motors - 5.2 pounds