The starting of a large Planer takes more toque then an induction machine can provide
in accelerating the mass of the single edge blade in a massive flywheel.
The first graph ( Third Pic ) plots the speed torque of a repulsion motor
which has a strong starting torque at low speed.
See the ( First Pic ) a simplified repulsion motor wiring diagram.
After 40 seconds the repulsion motor reaches speed and the brushes lift off the
commutator turning the motor into an induction machine for planing.
Here is a pointer
to an actual repulsion motor starting a planer wind-up
that you can see and hear
See the ( Fourth Pic ) a simplified Induction motor wiring diagram.
The second graph ( Sixth Pic ) plots the speed torque of a Induction motor
which has almost no starting torque at all ( used for fans )..