Subject: RE: BRIDGE SIMULATOR, ACTUATORS DRIFTING UP
Date: Thu, 16 Aug 2001 14:21:23 -0400
From: pcastald@atc.army.mil
To: rod.larson@mts.com

Yes, I compiled the script, and followed the procedure you provided, and I
did apply bigger preloads, -800. I had reduced the Master gain to 50%.  This
morning I went back to verify all these events. Started diesel after program
running fixes compiled and settings (Run1Force.set) applied.  With no
pressures on (no pilot on) I got drift on 11 and 15 they later returned to
normal then I got drift on 5 and 6 to about 15 in and then oscillating 1" pp
around 7". I turned the pilots on and had other drifting.  Then I set master
gain back to 100% things settled down and was able to run a few cycles.  Is
master gain the wrong adjustment when I want to do a percentage of loads in
load file? And what does the MASTER SETPOINT ZERO button do?  -Pat

-----Original Message-----
From: Rod Larson [mailto:rod.larson@mts.com]
Sent: Wednesday, August 15, 2001 6:13 PM
To: pcastald@atc.army.mil
Subject: Re: BRIDGE SIMULATOR, ACTUATORS DRIFTING UP

Pat,
I take it that this is in load control??  You are compiling the script with
the browser that puts actuators 1,3,5, and 8 in stroke control while others
are in load control?  If this step is skipped, then you definitely have a
problem.  Actuators in load control should not drift as long as you have a
tension (negative) pre-load.  Make sure you use -300 to -500 lbs for
pre-load to keep actuators in contact w/ the bridge.  If needed, try a
bigger pre-load force,  but the only reason that I think that can be a
problem is if the load cells zeroes have drifted and I don't think that is
the case.  With the hand valves turned on, ANY time the diesel is on, you
ARE in control, there is SOME leakage to the actuators anyway.
Rod

At 11:53 AM 8/15/2001 -0400, you wrote:
>Hi Rod,
>
>I am trying to run some basic load drive files and the some actuators are
>drifting up and tripping limits.  They will start drifting as soon as the
>diesel pump is on.  If I run files with pilot on they slowly migrate down,
>but as soon as I go to Main Low they start drifting up. It might get
through
>one cycle before tripping out on stroke limits - actuator seems to vary but
>is usually within a certain subset ( 3,4,5,6,8,11,12,17,18)   - any ideas?
>am I missing some setting?
>
>Pat
>
