QUOTE(John Bigboote @ Apr 5 2009, 11:09 AM)

Sweet... what would happen if you put a 'rudder' in the middle of the force, like a ship...would that provide steerage?
Yes actually it would! Newton is amazing. The force pushing the car controls the motion of the center of the newton chain, the body of the car. The way a force effects newton is by pushing the center of mass of the dynamic object towards the center of the force. Since forward motion is controlled by the first object in the chain or the parent of the chain I could steer it by adding a different parent above the body that could be rotated or shifted to change it's center causing the force to push it in a different direction. I did some experimenting with rotating the force at various keys. Trouble is the front wheels are "locked" in a forward position. There is no steering. Just like real physics a car won't "turn" if the wheels stay straight. It sort of slides and drags slowing it down. In wire frame mode I can see that the wheels pretty much rotate in one direction... not totally. There is 1 degree of twist. If you set the twist of a newton chain object to 0 it's equal to 100%. I wish there was a way to set that value to 0. One degree isn't much but it still has an effect and if each joint in the chain has 1 degree it adds up.
I originally had the car up higher with a "springy suspension". But the combined 1 degree rotations caused it to settle too far. Then I added cross bars on the axels to keep them from moving too much... then it got too complex so I went with a simple single axle across through toruses under the car. I need to make that connection swivel so it can turn. I probably don't need those "hooks" for the axles anyway since it it chained under the car. It keeps it from meandering off in all directions though.
-vern