Truck parts Dynamometer. (Why not a water brake?)

[Paul Neelands]

I've been reading this dynamometer thread for a bit and though I would
add my 2 cents.=20
It is probably easier to use a water brake than to deal with all the
wear and heating problems of a truck brake. However a truck rear axle
is probably a good source of parts.

The general concept (straight out of my Standard Handbook of Mechanical =
Engineering) is to mount a series of perforated disks to
the shaft one wishes to load. The disks alternate in being attached to
shaft (disk 1), fixed to the frame(disk 2), attached to the =
shaft(disk3).
The number of holes in the disk and the size of the disks are =
proportional to the amount of power to be absorbed. Put the entire thing
in a tub of water, preferably with the disks vertical and the shaft =
horizontal and vary the water level to control loading. For long runs =
and
high power levels a radiator and circulating pump may be necessary.

For some ball park type numbers, try 12 inch disks with about 50% of the =
disk as 1/2 inch holes. Say 3 or 4 disk in all.

Gives a very stable load and allows independent adjustment of load
and rpm

Paul Neelands