The driving wheels are fitted
into axle boxes which slide up and down in horn blocks. These are suspended
by leaf springs.
machined horn blocks and axles boxes for a model locomotive
The wheels are connected by
the coupling rod which itself has pivots to allow the wheels to rise and fall
independently. The rod is attached to crank pins fitted to the driving
wheels. A large counterbalance weight has to be cast into the wheel to allow
for the weight of the rotating rods.
coupling rods removed from a
The connecting rod is fitted to one
of the crank pins and to the crosshead and converts the reciprocal motion of
the piston to rotary.