MK4i Swerve Module

Regular price $377.00

Check this spreadsheet for current swerve module lead times.

The MK4i is the flipped motor, corner biased version of the MK4 module. The MK4i module moves the motors to a lower position where they are out of the way and better protected. Overall height and center of gravity are lower. The MK4i module also moves the wheel further into the corner of the chassis for a wider wheelbase which results in a more stable robot. Because the wheel is moved into an area the frame would typically occupy, the MK4i includes a secondary plate to properly box in the chassis.

Other Highlights of the MK4i module include:

  • On-axis steering encoder (zero backlash, module can be disassembled/reassembled without resetting encoder offset)
  • All plates made out of 7075-T6 aluminum
  • All steel gears
  • All moving parts are protected under top plate
  • Includes secondary plate to box in frame
  • 10-32 mounting holes on main plate for subsystems (e.g., collector)
  • 15mm width steering belt
  • Encoder guard to protect the steering encoder
  • Same frame-to-floor height as previous Swerve Drive Specialties modules
  • Same L1, L2, and L3 drive ratios as the MK4 module (same L1+, L2+, and L3+ drive ratios as the MK4n when utilizing the 16T Drive Pinion Adapter Kit available separately)
  • No 3D printed parts
  • Cable-tie “nubs” keeps cable-ties in place
  • Bottom and top mounted chassis options
  • Includes wheel tread cut-to-length, drilled, and pre-installed on wheel. This module now ships with black neoprene tread (blue nitrile is pictured), which extends the tread life even further.
  • Includes all hardware, including hardware to mount module to robot

The MK4i module has many parts in common with the MK4 module. Kits to convert the MK4 to MK4i are available. The MK4i module ships unassembled, and the following components are not included:

  • Drive motor (REV Robotics NEO, REV Robotics NEO Vortex, VEX Falcon 500, or WestCoast Products Kraken X60 recommended)
  • Steering motor (REV Robotics NEO, REV Robotics NEO Vortex, VEX Falcon 500, or WestCoast Products Kraken X60 recommended)
  • Steering encoder (CTRE CANcoder, Thrifty Absolute Magnetic Encoder, Redux HELIUM Canandcoder, or equivalent)

Note: The above steering encoders come with the ⌀.250”x 0.500” magnet that gets installed in the Swerve Module's Center Column. That magnet is not included in the Swerve Module kit.

CIM motors are not compatible with the MK4i due to their larger diameter.

The steering gear ratio of the MK4i is 150/7:1.

The MK4i is available in 3 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 drivetrain free speed of each L gear ratio can be increased ~14% by utilizing the 16T Drive Pinion Adapter Kit available separately.

The swerve module can be directly mounted to commonly available 2" x 1" aluminum tubing with pre-drilled 10-32 clearance holes (example), though it can be configured for 8-32 screws (see "Effective 30-Jun-2023" note below for additional details).

The module main plate typically mounts on top of the robot chassis, however, there is also clearance to mount the chassis on top of the module main plate to maximize ground clearance. 

Please note:

  • The NEO Vortex kit works for the NEO Vortex motors with the 8mm keyed shaft.
  • The Falcon 500 kit is primarily for the Falcon 500 motor. It can also work for the NEO Vortex motor with the Falcon spline shaft, but the shaft spacers are not included (they are supplied with the Falcon motors), and the Semicircle Spacer kit is also needed.

Effective 7-Aug-2023: This swerve module will ship with an updated Intermediate Shaft (V3), Base Pulley (V3) and upper bearing (non-flanged) for the shaft. Details:

  • The collective change enables the flanged bearing supporting the top of the Intermediate Shaft to be replaced with a non-flanged bearing. That bearing can consequently only be installed in the updated Base Pulley one way to help ensure the swerve module is assembled correctly.

Effective 30-Jun-2023: The six mounting holes/screws in the MK4i Swerve Module for attaching it to the drivetrain frame will change from using 8-32 screws to 10-32 screws. Details:

  • The change enables the swerve module to be directly mounted to commonly available 2' x 1" aluminum tubing with pre-drilled 10-32 clearance holes (example).
  • If you have placed an order that has not shipped yet before the above effectivity date/time and would like the 10-32 mounting option, please contact us with your order number to request the change.
  • If you place an order after the above effectivity date/time and would like the 8-32 mounting option, please contact us with your order number to request the change.

Approximate weights:

  • MK4i module with NEO motors - 6.0 pounds (Includes encoder, lower mounting plate, mounting hardware, wires, etc)
  • MK4i module with Falcon 500 motors - 6.3 pounds (Includes encoder, lower mounting plate, mounting hardware, wires, etc)

CAD Files:

Layout Drawing:

Parts List

    Assembly Guide: 

    Assembly Video: