42030 alternate: Rescue Jeep

A one-set MOC built from the 42030 Volvo Frontloader. It uses the four motors from the original set:

Servomotor for steering (+ working steering wheel),
XL and L motor for the rear transmission and the fake engine (V6),
M motor for the crane.

The Jeep has a two-wheel drive. The rear axle is pendular, and the steering features a Ackermann geometry. The two XL and L motors are coupled via a differential, which allows to add or substract their rotations (x = 220 rpm for the XL motor and y=390 rpm for the L motor). As a result, four gears can be emulated:

L forward, XL backward: V = y – x = 390 – 220 = 170 rpm,
XL forward, L off: V = y = 220 rpm,
L forward, XL off: V = 390 rpm,
XL forward, L forward: V = 390 + 220 = 610 rpm.

The model also features openable hood and doors, and adjustable seats.