Truck parts Dynamometer.

[Dave Williams]

-> our facility.  Building the rolls is a large task.  They have to be
-> machined on large lathes and balanced.  If you go with small diameter
-> rolls they must be carefully balanced as they will be spinning faster
-> then large rolls.

 The rolls on my Clayton chassis dyno are 8" in diameter and about 7
feet long.  Appropriate tubing for new rolls is $7/ft locally, and any
driveshaft shop should be able to spin balance them.


-> The tires slip on the rolls at higher powers, and there is a lot of
-> energy lost by the tires heating up as they deflect at the roll

 Yes.  They're only useful as full-range dynos for less powerful cars,
but they're quite handy for doing low speed and part throttle work on
any car.


-> our engine and chassis dynamometers is to use regenerative DC motors
-> as PAUs.  The DC motors operate as generators to absorb the power and

 I checked that out once.  An appropriately sized DC motor, new, appears
to be in the $15,000 range.  Apparently they sometimes show up on the
market as scrap, but I haven't found one.


 It's ironic that getting rid of horsepower is more difficult than
making it in the first place...