Dyno

Dyno for testing RC motors

Marc Decroubele from Belgium has been working on a dyno for some time, below is his description of the dyno and some photos of his test bench and the software he has created.

I am working on a combined test bench/dyno for RC motors. I started the development in 1999 and I hope to have a
full operational unit in 2005. The dyno uses the principle of measuring the acceleration of a known inertial load (flywheel).
I use the script off Brian Callahan (university of Michigan, 1997) as a base.
Mechanically the bench is composed of an alu base plate with a central guide who receives the flanges with the bearings. I made 3 mounting blocs for 3.5/7.5/15 cc motors and 3 different flywheels.
The dyno is mounted in straight line; motor, coupling, one way centrifugal clutch and flywheel. The flywheel is enclosed between 2 flanges for security.
RPM measurement is done before (Hall sensor) and after (optical sensor) the clutch.
For use as a test bench the flywheel is removed and the shaft is connected though a belt to an air propeller under
the mounting plate. The whole bench is controlled by a microprocessor, who assembles all the measured values, control the dyno sequence and send all the results to a PC.
The PC program has real time display of all measured values, display the power/torque diagram and permit complete
remote control of the bench. The controller has a stick to ease the start off the motor and also the cooling is locally adjustable.
Measured values:
RPM motor and flywheel.
Temperature: motor, water-in, water-out, pipe, EGT (exhaust gas temp)
Ambient temperature, humidity and pressure
Remote control:
3 servos for throttle, mix and flywheel brake. Full control of cooling pump, 3 on/off commands (fan + 2 free use)

Marc Decroubele.... email