George Kokalis, with Servo Kinetics, co-authored a white paper with Dr. J.F. Sarnicola, P.E., president of Sarnicola Simulation Systems, Inc., on the advantages of hydraulic motion over electronic motion.

The white paper is entitled, Hydraulic Motion vs. Electric Motion: An Honest Comparison for the Record.

Dr. Sarnicola provided all technical and scientific conclusions in the paper, which can be found in its entirety at, under the About Us section. The many reasons to choose hydraulic over electronic motion are described fully in the paper. Here is a summary of some of the many considerations the co-authors described in the white paper.

1. Hydraulic motion is dependable and proven over time. It has been around for 70+ years and most hydraulic systems have been operating two to three times longer than they were originally designed to operate.

2. In terms of flight simulation performance, one type of motion is not better than the other.

3. The hype about electronic motion being technically more advanced is just that — hype. Electronic motion solves the same problem as hydraulic motion, but brings with it a lot more baggage. With electronic motion you get an entirely different and more complex set of technical difficulties to overcome, which can translate into its own set of generally high-cost technical trade-offs.

4. Electronic motion systems do not consume less electrical power than hydraulic motion systems; in fact, those used in motion platform applications consume significantly more energy than hydraulic systems. A factor that generally is overlooked with electronic motion systems is that the installed power requirement is 20% greater, and thus consumption is greater. If you examine a motion platform at mid stroke position, with no motion being commanded, the hydraulic valves simply close and the HPU’s swash plate throttles back allowing the HPU motor/pump to spin at a very low energy consumption rate.

The electric unit continues consuming energy equal to the entire weight of the payload, and it heats up. This heating is considerable and it must be eliminated, or in technical terms, it must be rejected. In electrical systems this heat is rejected in the “people” space where greater air flow and cooling are required, resulting in more uncomfortable inhabited space.

5. Hydraulic wins over electronic when overloaded. Electric platforms are sized for a much narrower band of operation; beyond that band the platform will fault. A hydraulic system can accommodate a much wider range of operating parameters. If a customer asks for a system to be designed for an 8,000 lb. payload, but puts 12,000 lbs. on it, the electrical system would need to be replaced. A hydraulic system, with its wide operating latitude, would allow operation with the proper adjustment.

Check back with this blog for the next installment which will provide the co-authors thoughts on additional considerations in choosing hydraulic over electronic motion.

Servo Kinetics provides full-service industrial hydraulic repair, inspection and rebuild capabilities. We’ve been in business for over 45 years and have worked with industries that have very exacting standards and include some of the most tech savvy companies in the world.

Our hydraulic repair services include hydraulic pump repair, hydraulic motor repair, hydraulic field piping, flight simulator repair, reverse engineering services and more. Our commitment to consistent high-quality work and expertise has made us a trusted industry leader. Call us to learn more about our services!