Low torque/speed dynamometer 1

[alansimpson]

I wish to dynamiaclly measure and plot power output of a rotating device. Very low speed, loads 30 RPM and 10Nm.
Any instruments available or ideas?

 

[ivymike]

use a toothed wheel and sensor to measure rotational velocity, and use an appropriately placed load cell on the supporting structure to measure force, from which you calculate torque...

 

[GregLocock]

Or, more crudely, a blob of white paint and a stopwatch, and a lever arm with a spring balance.

Or more crudely yet, a chalk mark, a pendulum, a stick and a pile of rocks.





Cheers

Greg Locock

Please see FAQ731-376 for tips on how to make the best use of Eng-Tips.

 

[MikeHalloran]

Very nice instruments availabe from Magtrol, Buffalo, NY.

Bring your wallet.



Mike Halloran
NOT speaking for
DeAngelo Marine Exhaust Inc.
Ft. Lauderdale, FL, USA

 

[sreid]

Brush type DC motors make pretty good dyno loads. Use it as a generator and load it with a big power potentiometer. You would need a motor with a low armature resistance due to the speed you are going. The amount of torque can be measured by the armature current or with a torque arm/scale attached to the motor stator.

 

[MintJulep]

Ivymike and Greg's solution still require something to apply load to the device.

Rather than mounting the lever to the motor support, mount the motor rigidly.

Put some friction material on one end of the lever, and a forceometer on the other. Let the friction end ride directly on the motor shaft.

Add a tachometer of some sort and... Voila! Home made brake dynamometer.

 

[amorrison]

See

http://www.apicsllc.com/apics/WP_2/WP_2.htm