Swerve Drive Specialties is excited to release the MK4c Swerve Module. The MK4c is a corner-biased, non-inverted swerve module. Modules are in stock and ready to ship.
The MK4c combines the non-inverted motor layout of the MK4 module with the corner biased high strength plate construction of the MK4i module. This results in the smallest footprint SDS module yet. The MK4c occupies a 4” X 4” area measured from the inside edge of the chassis.
The process for swapping the motors is the same as the MK4 module. You remove the 4 motor plate screws and then have access to the 2 motor mounting screws from the bottom. The steering motor pinion fits through the motor plate and motor riser, but the larger drive pinion does not.
One of the things we did in 2023 to gain additional clearance below the frame rails was to mount the frame rails above the main plate and then mount the bottom plate on the top:
Will this configuration work with the MK4c as well? Will the bottom plate fit around the motor plate?
I have always found the motor plate mounting screws on the Mk4 a bit finicky with the set up of two threading from the top and two threading from the bottom. Keeping everything lined up, while adding locktite and keeping the stand offs from sliding off, is rather tricky, compared to the ease of the rest of assembly.
I think that a big serviceability upgrade would be to add another dedicated mounting screw to each motor, and then have the motor plate attach with 4 screws from the same direction. In a situation where one or both motors needed replacement, this would be a huge time and complexity saver.
Not sure if this is feasible, just always a hope of mine for the next generation mk4.
Looks amazing! If anyone is buying this module (or even regular MK4’s, please protect your motors. We experienced way too much pain with extensions into our frame during the 2022 season, which was why we decided to switch from MK4’s to MK4i’s. And since the motors are even closer to the edge of the frame, it makes them more vulnerable.
Module size is weird to express because the outside dimension is the tabs to pick up the 2x1, which doesn’t really say much about the size of the module and how much space it takes up in your robot. Additionally, some modules overall dimensions make them appear smaller because they are inset from the 2x1 by 1/4".
My preferred method for comparison is measuring from outside of frame 2x1 without mounting tabs, This allows for easy “space between the modules” math when choosing frame perimeter / overall robot size.
By this metric, here are the SDS Module sizes without mounting tabs from the outside of the mounting 2 x 1 (rounded to nearest 1/4").
Mk4: 5.75 x 5.75
Mk4c: 5 x 5
Mk4i: 7.5 x 7.5
Mk4n: 5 x 9
WCP Modules for comparison:
SwerveX Tube Mount: 5.5 x 5.5
SwerveX Corner Mount: 4.5 x 4.5
SwerveXS: 4 x 4
Rev:
MAX Swerve: 4 x 4
ThriftyBot:
Thrifty swerve: 7 x 7 (slightly over 7)
Edit: This ignores height and wheel size, which are definitely a factor in choosing your design, but is harder to summarize because of various motor options.
