In a message dated 1/22/2005 12:08:34 PM Central Standard Time,
dale.r@cox.net writes:

<<  Thank you very much for the idea.  It isn't directly
 applicable to my situation, because I don't have a car
 to use as a "chassis" test bed.  However, it did give me an
 idea - using a gang of disc brake assemblies, for creating
 an engine dyno that might come in at under $1000.  
 (Actually, a direct coupling to the truck rear-end might
 do the job - if the brakes are big enough and I can figure
 a way to take the strain reading directly from the axel
 housing.)
 
 Dale R.
 COZY MkIV #1254
  >>


There is more than one way to skin a cat.

Build a disc to bolt to the companion flange of a truck differential and the
flywheel of a rotary.

How about elongating half of the bolt holes in the backing plate, in an arc
to conform with the bolt circle diameter. Use smaller bolts and drop in a small
needle bearing around each bolt/stud. Now the backing plate can articulate a
bit around the centerline of the axle. Mount the transducer to a bracket
welded to the housing, and the other end to the backing plate. Calibrate the output
with a torque wrench.

There you go. A truck axle dyno.

Don't forget the math to take out the effect of the differential ratio, lest
you report some giant numbers.


Lynn E. Hanover