Mechanical Engineering


Scott Harlan P.E.

California Professional Engineer License M31719


19518 Creekside Ct.  

Salinas, California 93908


  • Prototype Design
  • Track Drive Design
  • Hydraulic Powered Equipment

The array of engineering projects I have worked on is diverse, but the one common element  is they virtually always involved mobile equipment.  My machine design experience has included equipment for the construction industry, agriculture, aircraft ground support equipment, and military.  These machines were towed, propelled with a hydraulic wheel drive,  track drive, or electric ground drive.

Weight and cost are critical issues on most mobile equipment designs.  To optimize a design  for weight or cost it is imperative to understand the materials and manufacturing processes that are practical for a given application.  Certain mobile equipment industries lag behind others in the use of optimal materials or processes for a particular design.  As a result of more than twenty years of design experience I have a broad exposure to materials and manufacturing processes.  In many cases I can help integrate new materials or processes into a design to help minimize weight or cost.  

Track drives are sometimes required for off road equipment, but track drive design almost always involves a steep learning curve.  Dirt grinding through componentry can cause rapid wear on track drive components if the designer has not selected the right materials.  Incorrectly designed track carriages may accumulate mud that destroys or derails the tracks.  Track drives are one of the most perilous and expensive components on mobile equipment.  I have experience designing both dual track machines and quad track machines (see lower right).  Using a consultant like myself can save both money and time by avoiding a part of the often painful learning curve of developing a track drive.

Building prototype machinery is fraught with risk.  Extensive prototyping experience has refined my ability to manage this risk and optimize the chances for project success.   This prototyping experience has encompassed projects ranging from one-off prototypes to machinery that would be produced in volumes of hundreds or thousands.  Design strategies change with production volume and understanding how to adjust the design is critical to producing a cost effective product.  If your mobile equipment project is large or small, I have the right background to help make it a success.  

This hydraulic tilt trailer is designed for easy loading and unloading of large equipment.

Hydraulic tilt trailer uses high strength, low alloy steels to produce a strong but lightweight trailer.


This folding trailer prototype has telescopic wings that support the combine during transport but retract when the trailer is empty.

Trailer prototype folds down to the ground to facilitate easy loading and unloading of a combine.


The rear tool boxes and support on this wrecker were made of aluminum to minimize weight.  Achieving  the weight targets on this machine prevented the need to redesign the entire fleet of trucks of this size.

Weight distribution and total weight were critical on this military wrecker, so many components were made of HSLA steel or aluminum..


This cargo loader was the smaller of two designs that shared an enormous commonality of parts.

Deflection is an important design consideration on aircraft cargo loaders because the front and rear platforms must interface correctly for successful transfer of the container.

The rear tracks on this dual track design swivel on a turntable almost 90 degrees.  This provides a very tight turning radius without plowing up a lot of dirt.

Greenleaf lettuce harvester was designed using dual tracks to make the loading and unloading safer.  A single track machine crests over the knee on the trailer.  This can be frightening and dangerous on long single track machines.

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The life of both the track and this sprocket were almost tripled  through the use of an innovative sprocket design.