ERR Cruise M - TMCC question

The cruise M is a motor driver board which replaces the existing motor driver board in a factory TMCC locomotive. Given that the loco was already TMCC, the only thing it adds is cruise control and 100 speed steps.

These two things alone make the conversion completely worth the time and effort (which is low). The cruise M made my K-Line scale Hudson into a fine runner at all speeds.

The only way to change the chuffs per revolution is to change or modify the chuff switch/sensor, whatever type that might be.

I usually disconnect the chuff switch (microswitch, or cherry switch) from the chuff input and install a magnet on a small wheel (tender/pilot/trailing) and install a reed switch. Since the small wheels are generally half the circumference of the drivers, that gives approximately two chuffs per revolution.

Updating the chuff to 4 per rev is not too difficult. If the engine uses the sensor on one of the drivers, then all that is needed is a reed switch and 4 magnets. The two wires that go to the existing sensor need to be moved to the new reed switch and the four magnets need to be glued at the quarter positions on one of the drivers. Then glue the sensor to be triggered by the magnets.

I have upgraded two engines like this and they both are great.