ATR3-b1 framework - front

ATR3-b1 framework - rear

Although ATR3′s entire chassis is made of thick metal that can be readily drilled for actuator mounting, I have opted for a framework-based design to better support vehicles with limited chassis attachment points.  For instance, most cars have sturdy attachment points below the driver’s seat, whereas mounting directly to the plastic dashboard where the levers and buttons are located would be difficult.  Anton’s framework is composed of 1/2″ hollow square aluminum tubing, 1/16″ thick wall.  The outer cube is 21″ (53cm) wide by 5′ (1.5m) long by 2′ (61cm) tall.

ATR3-b1 framework - chassis attachment point

For rapid prototyping purposes, the framework is held together by #8-32 machine bolts rather than welds.  A welded framework would probably require only two attachment points; Anton’s framework has chassis attachment points at the front, rear, and both sides. The framework’s rigidity could probably be improved by grid beam-style tri-joints.