Subject: Aberdeen Bridge Test
Date: Fri, 28 Jan 2000 17:51:49 -0600
From: "Kaufman, Tom" <Tom.Kaufman@mts.com>
To: "Larson, Rod" <Rod.Larson@mts.com>

Rod:
The loading curves you did for me have an important piece of
information.  It shows the rise time(velocity) needed for each of the
actuators.
This servo-valve flow is then easy to find.  My conclusion is that the
60 GPM Moog valves would be too small.
They would almost meet the flow for tension side, but the flow out of
the compression side would cause too high of a pressure drop over the
S/v.  (If we slowed down the time for center cycles, we push the higher
velocity cycles outward toward ends(with shorter strokes).  We still end
up with higher velocities than the 60 GPM valve can handle).

Therefore I would like to use the normal 90 GPM 256.09.  I did my best
to check the costs, and it looks like we can save over 10K by using the
bigger valves.  It means that you will need to use (18) 497.15 valve
drivers, and this adds one more 497.01 chassis.  I looked at a normal
vertical rack, and it looks like we still have plenty of room for (4)
497.01 chassis and the 498 box.  Let me know if you see something that
is a show-stopper.
On Monday next week, I plan to give the actuator group the go-ahead to
complete BOM's with the 256.09 valve.

Another issue:  What temposonic do you want in the actuator.
Digital--or analog?  When I did my count of transducer modules, I
assumed we would have a module for the tempo, but I did not know if this
is really needed.  What is really needed????   If digital, do we need
any 497 module?
Tom K.
