This a is a swerve I drew up during the build season with the specific intention of not needing a CNC machine. However, you do need a rotary table for your mill with this design.
The sprockets for powering are not shown, but they could simply be attached with a keyed connection. The steering sprocket is shown, but the motors for steering aren't because we didin't know what method of actuation we wanted or which motors we would need elsewhere. I would recommend steering the front wheels together and the back wheels together for a little bit of flexibility in steering modes.
The CIMs can also be down into the frame. The only reason they a sticking up is because of a few specific wiring issues that pertained to my team's 2009 bot.