It IS very likely that I will have to return in a few months to answer questions and give more training. These guys are starting from ground zero (no test experience and no hydraulics experience). I can probably connect a future trip w/ a trip to Korea, Japan or Taiwan after the 1st of the year. I can probably stuff it in some other account.....

There are some problems w/ the system that you, as a PE should know about. Do NOT take this criticism personally cuz you have had not much experience in this area before. The customer can maybe live with these, but some earthquakes will give them trouble. Kobe cannot run on the system because it IS within the capability of the table but there is NOT enough accumulation. Typically, the performance curve is not enough. Kusner has a sizer that puts out the recommended accumulator sizing given a pump size and actuators. From my measurements, there is no more than just flow averaging accumulators on this system. In addition, the filtration is compromised without a kidney loop constantly filtering the oil. A seismic system spends a great deal of time NOT flowing very much oil, even during tuning. I have had to run VERY large sine waves a few times to help clean things up..... also dither around 1-2 volts. Also, the heat exchanger does not seem big enough to handle tropical climates. Today, the ambient temperature was 38C and that caused us to get a little hot. When we were running hard the temp went over 55C. When the oil goes over 50C, the 3-stage servovalves tend to squawk and screech at you. Yesterday we went all the way to overtemp at 65C cuz we ran out of water in the tower. Filled up today and we managed around 50C worst case. The controller has NO A/Ds or D/As in it. This makes it impossible to put in any analog signal from customer conditioners to acquire w/ the system data. Also, no outputs means he cannot use his National Instruments Data Acquisition system to record our system stuff along w/ his signals to time correlate them.....

Brad has one bug left in the system. He does not have a X or Y DOF displacement signal output. The position he shows contains the angle cross-coupling in it. That is ok for the actuator displacement, but NOT for the DOF displacement. Cross-coupling compensation should not be shown in DOF. For example, if you stroke X a total of +/-250 mm, the Y actuator moves 12 mm. Brad shows the Y DOF moving 12 mm instead of ZERO as it should. I will try to get this fixed by tomorrow if I can. It is not a show-stopper, just embarrassing...

Other than that Mrs. Lincoln, how did you like the play?? NO...it has not been bad at all. The system is actually a sweetheart and runs VERY well. I really like those bearings. Just have to warn the customer not to run 30Hz sine waves in one place for an hour.....just wish we had some accumulators.....customer is also very understanding and pretty nice people.