My first synchro-drive. In this kind of set up all the wheels are synchronized in both steer and drive. When a turn is executed, all the wheels turn in unison and as a result the platform itself does not rotate. There isn't any mechanical limit to the steer. The wheels can rotate 360° and do as many full turns as you want.
I found this project very challenging, and I'm quite happy with the result, but I must say that due to the frictions the bot is very slow and I guess this platform is not really suitable for further developements.
To replicate this project the key parts you need are four dark gray 16 tooth gears with clutch (6542) and a lot of chain links.
My brother Giulio succeded in using the (empty) differential gear in place of the 6542 gears.
Here you can see the structure of the platform (RCX and bumpers removed). There are two long chains on two different layers. The lower one controls the steer, while the upper one drives the wheels.
The drive power travels along the rotation axis of each wheel group, through the dark gray gears whose hole doesn't "take" the axle.
Top view (RCX and bumpers removed).
This page is not connected with or endorsed by The LEGO Company. LEGO, LEGO TECHNIC and LEGO MINDSTORMS are trademarks of The LEGO Company.