Thanks Alderon for the diagram and method, I'll try it out. In my expermients, I have found ways to do some more complex linking still controlled by one object, but as you say, there is a definite problem with wobbling. And some linked objects tend to take a walk, moving in unexpected ways. I agree, we need more control points in Bryce and more flexibility for this type of project. Bikermouse-- Not sure why you are stuck in Bryce 3.1, and I can't help you there, as I no longer have or use it. These constant upgrades are a strain on the wallet, aren't they! As to transmission for reverse, I remember reading about that somewhere. The old steam locos don't have gears at all, just the tie rods that control the wheels. I believe they get them to go in reverse by some sort of action with the steam valves (which in Bryce are not required, of course.) As I understand it, locos use a two stroke piston, where the steam can be sent into either end of the piston case (this also doubles the power of the machine since it is powered when the piston moves forward, and powered when the piston moves backwards), which is different from an auto engine, where the fuel always enters the top of the piston (the bottom is open to the internal crankshaft). To go forward, they ensure that the steam enters one end first that will cause the wheels to rotate one way, and to reverse, they swap the valves, so the steam enters the other side first. At least I THINK that's how they do it. I believe I remember seeing some documentaries on TV about steam enthusiasts who drive the real antiques, and if I recall, sometimes, the things would start in reverse unexpectedly, and they'd have to switch the valves. I'm no expert on that. Mahybe someone in this forum knows more about it. Model trains are easier, you just reverse the current!