[DonRotolo]

I am not a programmer, so I really can't help there.

However, I have a lot of experience with 6-wheel drive and plaction wheels, and having trouble turning is not unusual.

Are the center wheels exactly level with the outside four wheels, or are they 'dropped" down a little (1/16-1/8" = 2-5 mm)? If they are level, you will have trouble turning, and that can't be fixed in software (that I know at least).