Tank Drive Mecanum

[vhcook]

Ok. I understand, and this is possible. I haven't done it before, but it would require reverse-engineering the Holonomic drive VIs a bit to figure out how to manipulate your joystick inputs before feeding them to the stock VI to get the desired result. Basically, you'll need to mathematically convert your two Y and two X axes into an X, Y, and Z (rotation) value, each of which should be in the range -1 to 1, with 0 being stop.

If you use holonomic cartesian, you can get an effect just like movement in Halo or most first person shooters using unmodified axis inputs. Left Y axis = forward/reverse (Y input), left X axis = strafe (X input), right X axis = twist (Rotation input). You can, of course, reverse the X axes to match your driver's personal taste. This is very easy to code, and will work out of the box (although you should initially test on blocks to make sure you have the correct motor polarities in Begin.VI (all motors should go forward when you're pushing the left stick forward, and any that are backwards can be fixed by setting the appropriate invert option on the RobotDrive 4 Motor Open to True)).

Given the amount of time you have until your competition and the amount of testing you will need to do on practice day, my recommendation would be to do this the easy way and pick a driver who is comfortable with Halo-style controls. If you still want to go with the hard way, I'll be happy to provide more advice, but I don't think the benefits are going to outweigh the time cost for development and testing at this point in your season.