Mechanical Design

Conceptual Design

Conceptual design is the first phase of design and involves performing design trade studies to determine the optimal configuration prior to initiating the detailed design phase of a project.  Conceptual design might start with a hand sketch but will typically involve generation of a 3D solid model with less detail than the final models.  Depending on the project requirements, the conceptual model may be used to develop a Finite Element Model (FEM) to perform preliminary analysis or used to check engineering requirements including sizing, fits, function and form.  The conceptual design is also used for determining overall project costs for engineering proposals.

PEI utilizes the following Computer Aided Design (CAD) packages:



A solid modeling computer-aided design (CAD) and computer-aided engineering (CAE) computer program that runs on Microsoft Windows.

PTC Creo

Creo is a family or suite of computer-aided design (CAD) apps supporting product design for discrete manufacturers and is developed by PTC. The suite consists of apps, each delivering a distinct set of capabilities for a user role within product development.

Creo runs on Microsoft Windows and provides apps for 3D CAD parametric feature solid modeling.

AutoDesk Inventor

Autodesk Inventor is a computer-aided design application for 3D mechanical design, simulation, visualization, and documentation developed by Autodesk.


AutoCAD is a commercial computer-aided design (CAD) and drafting software application developed and marketed by Autodesk. AutoCAD is used across a wide range of industries, by architects, project managers, engineers, graphic designers, town planners and many other professionals. 

Detail Design

Detailed design is the phase where the design is refined and specifications are generated. Detailed design can include outputs such as 2D and 3D models, final cost  estimates, and procurement plans. This phase is where the full cost of the project is identified in most cases and manufacturers can provide cost estimates for fabrication. At PEI, we work in parallel with our team of structural analysts to ensure the project schedule is maintained by incorporating analysis driven modifications into the design efficiently.  


Parametric solid and surface modeling allows for updating and regeneration of features during the design process. SolidWorks, PTC Creo, and Autodesk Inventor models are composed of datum (planes, points, axes, and curves), surface, and solid geometry. The dimensions controlling these geometric features can be modified
or redefined at any time. Relationships between geometric features may be added to control symmetry and relative positions of features and many other complex relationships.


Engineering drawings are generated from the 3D solid models and form the instructions for manufacturing and assembly.  We have generated numerous drawing packages for assemblies including full motion flight simulators, structural aircraft modifications, spacecraft ground support equipment, and space flight hardware.

  • Assembly drawings including composite, welded, and mechanically fastened structures
  • Indented Bill of Material
  • Drawings in accordance with ASME Y14.100 and ASME Y14.5-2009

Mechanism Design

Our engineers have designed mechanisms for spacecraft antenna deployment, aircraft autopilots and automated landing systems, and flight system controls for aircraft simulators.  Along with engineering design, we also have significant experience with structural analysis of these systems.

Composite Structure Design

Our engineers have designed numerous composite structures  for motion-based flight simulator components, aircraft modifications including nose and radome assemblies, and spacecraft structures.  Our experience includes high performance composite structures including sandwich panels with aluminum, carbon, and fiberglass face sheets with aluminum honeycomb or foam cores.  We have designed numerous molded composite structures with carbon and fiberglass skins, foam core, and integrated attachment flanges.

Recent Mechanical Design Projects

Orbital ATK Satellite Shipping Container

NASA HU-25A ACTIVATE Program - Aircraft Crown Modification

NOAA Twin Otter - Drop Chute Modification

Beechcraft Bonanza A36 - Battery Shelf Redesign

B-52 Aircrew Trainer Upgrade

Dawn TGA Plume Shield

AMC-21 Payload Module Shipping Fixture

Lockheed Martin L-Frame Fixture

Hubble Space Telescope Servicing Mission (STS-125)

Redesign OC-Series of Ophthalmic Examination Chairs

Design of Powder Coating Spray Gun

Redesign of a Stationary Bicycle Trainer

Design of Mattress Support Frame

Design of Metric Vision Equipment Cart

Visual Upgrade of P-3C Flight Simulator

RADARSAT-2 High Gain Antenna Deployment Hinge

Satellite Shipping Container and Handling Fixture for Antonov An-124-100 Aircraft Transport.
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Mount four instrument pylons (three large and one small supporting five instruments total) to the upper fuselage of an HU-25A research aircraft for NASA Langley.
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Design a new drop chute located in the aft baggage compartment for NOAA's fleet of four Twin Otter aircraft
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Redesign battery support shelf for support larger aircraft battery for piston engine to turboprop conversion
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