Subject: Toyota modifications
Date: Mon, 1 Mar 1999 17:56:12 -0600
From: "Gram, Marty" <Marty.Gram@mts.com>
To: "Kusner, Dave" <Dave.Kusner@mts.com>, "Chen, Hans" <Hans.Chen@mts.com>,
     "Larson, Rod" <Rod.Larson@mts.com>, "Hessburg, Thomas"
     <Thomas.Hessburg@mts.com>

This weekend, Joe was able to achieve a much improved waveform on  sled
acceleration.  He made 2 changes:  added a mandrel to the poppet valve,
and increased decel pressure from 250 to 800 psi.

The mandrel addition apparently did not change the drive force on the
poppet.

The waveform was not checked with just the increase in decel pressure.

The increased decel pressure eliminated some 5 kHz noise that was
thought to be caused by cavitation.

At this point, we do not know whether the mandrel had any effect on the
waveform.  It may have added damping to the spool (there is no damping
provided by the servo loop at this point).

I will continue to monitor the Toyota program to see what problems we
might have on Volvo.

--Marty
