ATR2-b1: Top

ATR2 is based on a stock Stampede Traxxas VXL.  The plastic central chassis has been replaced with an aluminum framework.  ATR2-b1 (build 1) is pictured with the original electronics in place, as high speed mobility testing helped to verify that the modified Ackermann geometry (lengthened chassis) would not cause steering problems.

The framework, built by Andy J. Mullen, is composed of hollow square aluminum tubing, 1/2″ on a side, 1/16″ thick wall. 8-32 machine bolts of various lengths and thin predrilled metal pieces (actually spare parts from an Erector set) hold together the framework.  After assembling into a full cube, the framework is sized to host an Asus Eee 701 on the uppermost surface.

ATR2-b1: Bottom

A Tekin Redline 7.5 brushless DC motor feeds the rear gearbox, driven by the stock Velineon VXL-3s motor controller powered by a Venom 4500mAh 3S LiPo.  The 5500kV Redline 7.5, a replacement for the stock Velineon 3500, contains a built-in quadrature encoder (4-wire) to reduce cogging at low speeds and provide dead reckoning feedback.