Designing from the Outside In: Reverse Engineering

By BARB SCHMITZ | Published: NOV 14, 2011

Product design today is largely a digital effort. Paperless design has been something that writers and analysts in the industry have been writing about for years, but the reality is that though designs can be tested, verified and validated digitally, physical parts and prototypes remain a reality for most manufacturers.

As a result, capturing data from physical objects and putting that data back into the digital model is often a crucial part of the design cycle.  With the use of 3D CAD systems on the increase, reverse engineering has become a practical tool to create a 3D virtual model of an existing physical part that can then be used in 3D CAD, computer-aided manufacturing and other computer-aided engineering applications.

More manufacturers are adding reverse engineering to their product development efforts, in part, because the costs of the scanners and other hardware used to input measurements have dropped dramatically in price. At the same time the hardware has gotten smaller and easier to use. The software has also become easier to use and the process of converting and managing scanned data simplified.

The reverse engineering process requires hardware and software that works together; the hardware is used to measure the object and the software reconstructs it into a 3D model. The physical object can be measured using 3D scanning technologies, such as coordinate measuring machines (CMM), laser scanners, structured light digitizers or computed tomography.

Let’s take a look at some of the advancements in reverse engineering technology, from the 3D laser scanners to the software that helps convert the scan data.

Scanning new advancements

A growing number of engineers are using laser scanners to help create prototypes for new products and ensure their conformity to original CAD designs. Even when prototypes are produced using the latest and most accurate methods, they still often need to be measured and checked against CAD designs to ensure accuracy for the customer. Laser scanners make it easier to capture 3D data from physical objects.

New 3D laser video scanners capture a 3D image in each frame and then combine them automatically into a single mesh. The scanning process enables users to walk around the object while continuously videoing it from 360 degrees. The video-based scanners measure speeds of up to 500,000 points per second, making them faster than laser scanners and are able to scan moving objects as well as stationary ones. Because they are portable, they can be used for sports, medical, computer graphics, architecture, prototyping and manufacturing applications.

Traditionally scanners required multiple setups and fixed-position tripods, mechanical arms or external positioning devices that must be aimed at re-aimed at the target surfaces. New handheld scanners can digitize 3D surfaces in real time and capture surface information in full 24-bit color, rendering the complete picture of the object, not just the geometry.

These handheld models are ideal for scanning objects in tight spaces. Also, they capture data in a single reference model so users don’t have to invest the time or risk errors post-processing to stitch multiple scans into one. Color 3D data enables more realistic and data-rich visualization and concept models, making it perfect for product design and reverse engineering.

On the soft side

Several improvements on the software side have also made the process of reverse engineering easier and faster.  The result of scanning a physical object is a point cloud of data, which is often enormous in size. With previous versions of reverse engineering or point cloud processing software, users would then weave surfaces through those point clouds, continually tweaking the accuracy and fit. The result was a model with no features, parameters or intelligence, just geometry.

Today, reverse engineering software is now easier to use and more affordable than ever. It’s also tightly integrated with CAD programs so engineers can access the most important features through their CAD software. Users can scan objects and then import the scanned data into reverse engineering software. The software processes the 3D point could data and then convert it into a model, a neutral, surface-based CAD model or a mesh that can be simulated digitally.

When further optimization is required, however, these models often lack the intelligence or design intent from which to make further refinements and changes. The wider adoption of direct modeling tools could change that. Direct modeling capabilities enable designers to direct manipulate model geometry without regard to its history, making it much easier to manipulate and tweak surface-based models created with scanned data.

Image by Paolo Tonon

Simulation Tools Help Answer “What if” Queries Early in Process

By BARB SCHMITZ | Published: DEC 19, 2011

Better designs result when chances are taken, mistakes made, and many different avenues are explored. Innovation results when designers and engineers are allowed the luxury and time to explore many different design options. It’s only when all these various directions are explored that a clear path to innovation emerges. Despite this, production schedules, budgets, and ship dates often hinder the ability to explore many options. After all, time to market in today’s brutally competitive, increasingly global markets remains of paramount importance.

Analysis and simulation tools put the power of innovation in the hands of designers without sacrificing crucial time to market by enabling them to ensure the quality and performance of their designs by testing them digitally for valuable technical insight early in the design process. Competitive pressures have lead to engineering simulation being adopted more and more across all industries as a strategic tool for driving innovation and reducing development costs.

With effective and accurate use, simulation software can help engineers predict product performance, gain insight, reduce the risk of failure, lower production costs, cut down on use of raw materials, and reduce over-design. Not only does this process produce better and higher-quality products but can also reduce warranty claim costs due to product failure.

There are several different types of simulation tools, though the ones most used by design engineers are finite-element analysis (FEA), computational fluid dynamics (CFD), and multi-physics software. FEA software enables engineers to understand the affects of forces and stresses between parts by applying bearing loads, pressures and torques to model geometry. CFD software enables designers to study conduction, convection, and radiation heat transfer to better understand the effects of temperature changes on parts and assemblies.

Multi-physics simulation, an offshoot of traditional FEA, enables engineers and designers to create virtual prototypes of their designs operating under real-world multi-physics conditions, or where multiple types of coupled physics interact. Multi-physics simulation tools simulate the interaction between structural mechanics, heat transfer, fluid flow, and electromagnetics within a single environment, making them ideal for mechatronic design.

Not just for experts. Simulation tools were once used only by white-cost-wearing “specialists,” which made it difficult for the analysis results to be fed back into the design loop. Collaboration between analysts and engineers is often complicated due to different domain knowledge, special techniques, and the use of different languages. Analysts think in terms of material properties, load cases, stress and strains. Engineers, though well-trained, do not have the familiarity with the finer points of nonlinear mechanics, fracture, creep, yield, and phase transformations, all important to FEA.

CAD integration. Vendors have worked hard to develop simulation tools that can be used by design engineers by closely integrating their tools with CAD software, improving the user interface, and using jargon common to engineers. Engineers can import their CAD models directly from their CAD software to test for strength, to show motion, and to explore fluid dynamics and heat flow around and through products.

Anticipate the unexpected. Simulation tools enable engineers to optimize the performance of their products and design them to be immune to variations in parameters, such as material properties, dimensions, and environmental conditions, even unanticipated customer usage. By digitally optimizing the product by taking into account any possible problem or accidental variation in use, engineers can ensure optimal product performance.

Better meshing. Meshing—the breaking down of a computer model into small pieces suitable for computer simulation—is critically important to gaining accurate results. The more dense the mesh, the more accurate the solution will be. Analyzing large models, however, is a very compute-intensive task so simplifying the geometry by removing features, etc., has become the industry standard method of dealing with this problem. Simulation tools now offer at least partially automated meshing, which greatly simplifies the process of preparing geometric data for analysis.

Go direct. Models created with traditional, parametric history-based CAD tools can be difficult to use with simulation tools. Direct modeling tools make it easier for users to incorporate simulation into their design process because they can edit geometry directly, without regard of its history. Direct modeling tools also make it much easier to remove features from models to prepare them for simulation.

Real-time results. It wasn’t that long ago analysts would set up their simulations, go home, and come back the next day to see the results. Thanks to more powerful, yet inexpensive workstations and more advanced simulation codes, those days are long gone. Today there are products on the market that perform simulations in real time, so engineers get answers to “what if” queries instantaneously.

Six Cool Creo Community Areas

By LINDSEY CHRISTENSEN | Published: JAN 13, 2012

For a Creo user, the PlanetPTC Community can be your library, water cooler or even playground.  It is the go-to place for group discussion around PTC product help straight from your fellow users.  But there is a lot of other interesting Creo content to be found there. In no particular order, here are the latest, greatest, and my personal favorites from http://communities.ptc.com

1. Community Hero of the Month:  There’s a new pick, you guessed it, every month! Recent inductee and Senior designer Steve Choryan has been a designer for over twelve years in automotive, aerospace and hydraulic motor design.

2. New Capabilities in Creo Parametric 1.0 That You Have To Try: Just one of many posts from PTC Express bringing you insightful step-by-step tips and tricks for Creo.

3. Fun Stuff: Lego cars, toys, characters, animations and more- there are a few different areas to let your inner-child-engineer let loose and have fun with Creo.

4. Nordics Now!: One of the larger user groups growing an interactive space in the community.  Is your local “UG” online? View event photos, check out agendas and more between the live meetings.

5. Photo Albums:  Once again designers run the gamut from a sketch of a mustache to a model of a corrugated coil.

6. Things Not to Say to an Engineer: A hilarious thread started by community manager Dan Marotta around the phrases you hate to hear at work.  “Don’t fight the data!”

So what are you waiting for? Join the community and start connecting today!

Design News: CAD Resurgence Fueled by Technology

By ADMIN | Published: DEC 29, 2011

“This younger, more skilled, and more mobile workforce is demanding tools that work the way they do,” Maher says. “One of the biggest, most profound shifts we’re seeing is that the data is traveling with workers to the field, the shop floor, the construction site, etc. That’s long been an ambition — now it’s a reality.”

In keeping with the new technology advances, Maher believes CAD will continue to evolve with lightweight, more easy-to-use, less expensive tools. She cites PTC’s efforts around the Creo line of apps tailored for specific tasks and specific roles as a harbinger of how CAD tools will continue to evolve. “People are looking at their CAD systems for more efficiencies,” she says. “They’re looking for better ways to create data and more ways to use the data. Most important, CAD customers are visual people and they want to interact with visual data, including 3D, simulations, and point cloud data.”

Read the full article here.

Engineering Students Win Creo Challenge with Modified Torpedo Boat

By LINDSEY CHRISTENSEN | Published: DEC 27, 2011

At the University of Limerick, every year the fourth year Advanced CAD course challenges its students to create a unique model based on a theme. This year’s theme? Land and Sea Based Military Vehicles.

Fourteen groups of four or five students teamed up to compete in the 2011 contest, each using Creo as their design tool. Note that these aren’t first-time CAD users. Engineering students begin using PTC design tools in their second year at the university. Some use the software during extended internships as well. By the time they reach the Advanced CAD course and its modeling challenge, the students are months away from entering the profession as trained engineers.

This year’s 2011 winner was a Vosper MTB, a boat designed after those used by the Royal Navy.  But, because these are engineering students, the winning design featured improvements over the original WWII-era boat.

“Our modifications included a safety rail,” says co-designer Eoghan O’Shea. “We also added a stepped hull, which increases the top speed of the boat, and armaments such as the BOFORS 40mm cannon.”

O’Shea says that the group appreciated several strengths in the Creo’s parametric design software for this project: Its ability to handle large assemblies and complex geometry, versioning control, and rendering.

He estimates the team worked 350 hours creating the model and an additional 13-15 hours on rendering. Here it is—with music and animations. Enjoy!

Credits

The University of Limerick team included

Cian Gallagher -4^th Year Mechanical Engineering

Shane Greaney -4^th Year Mechanical Engineering

James O’Connor -4^th Year Aeronautical Engineering

Eoghan O’Shea    -4^th Year Mechanical Engineering

Dr. Phillip Griffin was class lecturer

O’Shea further credits his entire class for the success of his team’s model. “A number of excellent projects were created, and in my opinion that was driven not only by everybody’s willingness to help each other out but by the great atmosphere of friendly rivalry.”