Dimensional Measurement Blog

Lockheed Martin required Q-PLUS Labs' measurement expertise to generate quick results via 3D scan data of the rear doors of the USS Freedom in San Diego, California. As a new breed of warship, the littoral combat ship (LCS) was designed to be a fast and formidable surface combatant with warfighting capabilities such as mine clearing, anti-submarine and anti-surface warfare.

Introduction

At 378 feet in length and composed of a high speed, semi-planing steel monohull with an aluminum superstructure, the USS Freedom is a unique ship. It is the first-in-class littoral combat ship of its kind and is able to operate in a variety of environments and assignments from dangerous shallow water and near shore missions to minesweeping and humanitarian relief.

Our Process

Q-PLUS Labs went onsite with portable measurement equipment, using a range scanner to collect massive amounts of data in a highly time sensitive assignment, then post process it into the needed readings and analyses. Collecting data with the Faro Photon range scanner, which is capable of measuring roughly the length of a football field in every direction, Q-PLUS Labs' engineers were able to overcome the scanning obstacles involved with measuring onboard a currently active warship. One of the challenges in the scanning process was collecting scan data of exterior doors which involved attaching a harness an engineer as he maneuvered the equipment overboard.

In order to quickly move the USS Freedom out of port, Q-PLUS Labs was required to acquire the data rapidly and accurately, delivering results which would be used to improve the design of the ship's rear doors. These doors are located near waterline level to allow safe launch and recovery of watercrafts while the ship is in motion. The accuracy of the doors' measurements would allow for improved design to resolve the problems being caused by the shape and position of the currently installed doors.  

Case Study Update (11/19/15): Q-PLUS Labs is completing a very special and unique 3D scanning project on the USS Freedom's sister ship, the USS Independence! Look for the upcoming case study.

Dimensional inspection includes many types of scanning devices for a broad range of applications. In the realm of 3D Scanning, the level of detail that can be captured makes it the method of choice, especially for measuring very small objects requiring non-contact measurement methods.

Whereas contact 3D scanners collect measurement data by physically scanning the object with a device that comes into contact with every point on the surface, non-contact 3D Scanners collect immense amounts of data quickly without altering the geometry of the object. This is also an advantage for collecting measurements on the nano scale.

3 Types of Non-Contact 3D Scanning Methods

Laser-Scanning Confocal Microscopes
A confocal microscope uses a process called optical sectioning to collect images from various depths. These images can be reconstructed with a computer to create a 3D model of complex small objects. Unlike other laser systems, a confocal microscope only sees one depth level at a time, which allows it to generate a highly controlled depth of focus for very small objects with tight tolerances.

White Light Interferometry
This non-contact measurement system allows you to obtain surface measurements at the nanometer level. The technology behind white light interferometry uses wave superposition to measure distances based on data collected about reflected wave interactions. Interferometers can also be combined with microscopes to measure very small objects. Because they rely on the detection of waves and not optical images, interferometers are also useful for measuring objects with reflective surfaces.

Chromatic Confocal
Like interferometry, chromatic confocal also uses white light to collect measurement data. However, whereas interferometry uses the superposition of waves after they are reflected off the object, chromatic confocal measures the wavelength as it hits the surface of the object. This method produces more reliable results when measuring surface roughness or step-height depth, due to the minimum mathematical calculation required. The tolerances of large objects may allow the use of a thin whitening spray to facilitate scanning but the geometry of very small objects could be potentially buried by it. Fortunately, all of these methods work well with various types of surfaces from reflective to absorbent.

If you require any of these types of 3D Scanning methods, or if you're not sure what you need, the experts at Q-PLUS Labs are here to help. We'll work closely with you through every step of the process to ensure that you get the best results for your application. Contact us anytime if you have questions, or if you're ready to get started, call us today.

California State University, Fullerton's Society of Automotive Engineers (SAE) chapter chose Q-PLUS Labs to aid them with the challenge to compete in the Formula SAE, a competition which encompasses designing, building, and competing a mini-formula style race car that will be evaluated for its potential as a production item.

Introduction

Fullerton's SAE uses a Yamaha R6 Motorcycle engine, a large displacement choice for the 610cc class. The car's design utilizes the R6 engine as a stressed member to connect the drivetrain to the cockpit. This type of engine design requires the chassis to work with the engine as an active structural element of the chassis to transmit forces and torques, rather than using standard anti-vibration mounts to passively contain it. The R6 engine was chosen based off its high power output and ability to be used as a stressed member. In conjunction with suspension design and tire selection, the engine weight works well to keel the tires while heated under the track's conditions.

Our Process

Because the race car's design is based on the integrity and precision accuracy of the engine's measurements, Fullerton's SAE sought the expertise of Q-PLUS Labs' dimensional inspection engineers. Using a Faro Arm CMM, Q-PLUS Labs provided a dimensional analysis of each mounting point for the engine. These points are integral not only to the race car's design but also to the safety of the driver.

Given the engine's exact 3D measurements, Fullerton's SAE could confidently proceed with their design. They were able to retrofit and reverse engineer the chassis to properly fit onto the race car's engine. Currently in the manufacturing stage process, in a few months they will produce the assembled chassis to compete in the Formula SAE® Lincoln this June.