[Tyler2517]

One more thing about crab is that 116 inches of chain adds up to a lot of weight.
If you loss that chain your robot drops dead.
I would never chose to run a crab over a swerve the advantages of the swerve when in my opinion it would be easier to build a 4 wheel independent swerve over a crab with a turret on top. With the 4 wheel swerve you can do so much more.

Programming is harder. but mechanically building 4 identical gear boxes is easier then that plus a rotary turret that can hold weight. Add on that the system you build to turn the wheels/drive if that fails then you loss the drive.. (most of the time a loss drive means a dead robot).