Case Study: Parametric Snowmobile Engine

Reverse Engineering an engine to help University of Maryland Terps Racing beat the competition

Every year a select group of students in the Mechanical Engineering program in the A. James Clark School of Engineering at University of Maryland in College Park, MD compete in the Formula SAE (Society of Automotive Engineers) competition. The FSAE competition requires the team of students to design, build, and race their own open cockpit race car.



The University of Maryland team, called Terps Racing, consistently finishes in the top 10 against 80 to 120 other school programs annually. Aiming for a 1st place finish in the upcoming races, the team is experimenting with a new engine design.

The small autocross cars, usually weighing between 300 and 500 pounds, typically run on modified motorcycle engines. But Terps Racing is experimenting with using a snowmobile engine for the upcoming 2011 races.

During the design phase for a new gearbox for this style engine, the students realized they needed a 3D CAD model of their snowmobile engine so that they could accurately design within the tight tolerances necessary to the mounting points.

Terps Racing approached Direct Dimensions for help with creating a dimensionally accurate 3D model of the engine to aid in their design and we were happy to help!

Here is a review of the major steps in this process:

Step 1) Using a combination of FARO's portable CMM arm and laser scanner, Direct Dimensions' engineer Michael Lent digitized the important geometric interface features on the engine. He then captured the complex casting shape with an attached laser line probe. The FARO system was a great fit for this project because it provides both a contact probe for high accuracy geometric features and a non-contact laser scanner for the complex contoured surfaces.



Step 2) By utilizing a variety of software, including PolyWorks, Geomagic, Rapidform and SolidWorks, the Direct Dimensions engineers quickly merged and modeled the 3D digitized data with the laser scanned 'point clouds' into a hybrid of a parametric solid-based feature model with the watertight complex NURBS surfaces. This file is readily usable within CAD software, such as SolidWorks for the re-design effort.



Step 3) This final hybrid model, which offered both the exact representation of the mounting interfaces as well as the accurate contoured cast surfaces was used by Terps Racing to design their 2011 car.

Case Study: Biodiesel University Mobile Lab

Promoting Energy Education in a Mobile Laboratory


Direct Dimensions traveled to a bus maintenance yard near Washington, DC to 3D laser scan a decommissioned city transit bus formerly owned by the Washington Metropolitan Area Transit Authority. The scan was performed for the Biodiesel University, a non-profit organization based in Olney, MD which seeks to educate students, teachers, and the public at large about renewable energy and environmental stewardship.

Dan Goodman, executive director of Biodiesel University, called upon Direct Dimensions to aid in converting the donated WMATA bus into a mobile educational lab, which Goodman has described as “part classroom, part hands-on science center, and part theme park ride.” The engineering challenge required cutting-edge capabilities from Direct Dimensions to not only scan the bus but also to create an accurate 3D CAD model so the bus can be repurposed for its educational mission. Given the current energy situation and attention to renewable energy, the project was captured on video for a featured story on ABC News.



To start the project, Direct Dimensions industrial designer Glenn Woodburn used the FARO LS long-range 3D scanner to take six scans of the bus’s interior and exterior in less than two hours. Each scan collected over 25 million 3D points providing a very high-resolution ‘point cloud.’

This captured raw data was then provided to Direct Dimensions designer Dan Haga, who created an accurate and detailed 3D CAD model reflecting the actual existing geometry of the bus.


Then using concept sketches and design input provided by Biodiesel University, Haga continued to layout and design the educational lab including the placement of the operational equipment that will eventually be installed in the bus when it is converted for its educational purpose


The final work, delivered in digital format to Biodiesel University, included several photorealistic graphical renderings and a 60-second animated 3D virtual tour of the overall mobile lab design.


By showcasing these materials digitally through its website and email, Biodiesel University can generate additional support for its program and mission. “The renderings and virtual tours present the concept for our mission in a very compelling manner. We’re grateful for the effort and enthusiasm that Direct Dimensions has shown for our project,” states Dan Goodman.

15 Great Projects Over the Past 15 Years

Over the past 15 years we've worked on many truly incredible projects. From art and architecture to aerospace and automotive, and these are just the A's. Below are 15 of our favorites, one from each year, and it wasn't easy to choose.

1995: Olympic Sculpture Brought to Life - One of our first 3D sculpture projects way back in our founding year, was to digitize a 4-foot model of a sculpture to help fabricate a monumental sized public art piece for the 1996 Olympics Games in Atlanta. Our 3D data was used for structural analysis.

1996: Power Generation Components - We reverse engineered our first compressor, impeller, turbine blade, and diaphragm way back in 1996 for upgrading power plants. Back then we used contact digitizers before the laser scanners of today existed.

1997: Recreating Unique Automobiles – One of our earliest historic automotive projects was digitizing a one-of-a-kind 1951 Cunningham roadster, considered the first modern American sports car. Our data was used to create reproductions.

1998: Digitizing the Wright Propellers - To recreate the Wright Bro.’s first flight from 1903 in honor of the 2003 centennial, an airplane reproduction company asked us to reverse engineer original propellers from several historic Wright planes. We collaborated with the US Army in Edgewood.

1999: 3D Digital Facial Prosthetics – Back in 1999 we scanned our first ear to make a medical prosthesis. We scanned a plaster cast of an ear and mirrored it to create a digital version of the missing opposite ear. This digital file was also used to make an RP for a surgical guide.

2000: Aircraft OML Scanning for Analysis – Early in the new decade we scanned our first of many "outside mold line" aircraft exteriors for CFD analysis. Back then we used a laser tracker, today we use the amazing Surphaser.

2001: Lincoln Memorial Scan - Just weeks after 9/11, the U.S. Gov't called with a very special request. They wanted to see how 3D scanning could digitally preserve monuments and artifacts in case of catastrophe. We demonstrated this with Abe at the Lincoln Memorial.

2002: Monumental Church 'Monument' - We traveled to Richmond, VA to 3D laser scan a decaying marble monument from 1811. Our completely restored digital model enabled the rebuilding of a new monument exactly as it was designed originally.

2003: Ray Lewis Marble Bust – We scanned Baltimore Raven's player Ray Lewis and made a beautiful life-like marble bust which was auctioned off for his charity. Since then we've done Amelia, Kelly Ripa, and Natalie Portman. Oh boy!

2004: Tomb of the Unknown Soldier – We laser scanned and digitally restored the Tomb of the Unknowns. Our 3D digital model may be used one day to fabricate a replacement for the cracked monument.

2005: Scanning the Liberty Bell - One of our most significant efforts ever has been our work with the Liberty Bell. We have scanned it three times over 6 years with increasingly better technology. Today we have a fingerprint level digital model of this famous icon.

2006: 3D Animated Political Cartoons – We have a lot of fun working with renowned political cartoonist - Kal. We scanned his exaggerated clay sculptures, including George W. Bush, Hillary Clinton and Barack Obama so he could make 3D animated political cartoons.

2007: 3D Scanning Helps U.S. Solider – For years we've worked with Johns Hopkins to develop radical new methods for 3D digital prosthetics. In 2007 we helped create a new nose for a soldier wounded in Iraq. This was truly one of our most rewarding projects and it was later featured on CNN.

2008: Laser Scanning Buildings for BIM – As early adopters of long range scanning for historic preservation as well as ships and airplanes, its logical to also scan and model large building structures. Often these models feed into BIM for downstream re-design and analysis.

2009: Scanning Aircraft with the Surphaser – We are constantly testing new 3D products from all over the world. This year we implemented the Surphaser as a fantastic new scanning tool for a wide range of projects - from cars to airplanes and everything in between!

2010: Matisse Sculpture 3D Analysis - A major art exhibition opened at MoMA in New York featuring extensive technical analysis of Matisse's "Back" sculptures. Our team played a huge role with our various 3D technologies for scanning, modeling, and analyzing the pieces for this important and unique exhibit.

Our team at Direct Dimensions, combined with our tools, history, experience, and skills, is quite unique in the United States and perhaps the entire world. We simply don't know of another organization with the variety of tools and talent that we've accumulated over the past 15 years. The above glimpse into 15 projects over our first 15 years amazes us and should amaze you too. It is very exciting to look back but even more exciting to think about what the next 15 years will bring.

Thanks for reading thru this and we welcome your feedback and reposts to your friends about this amazing list.

From your 3D friends at Direct Dimensions.

Case Study: 3D Transforms Idea from Concept to Digital to Manufacturing

John Jenkins, President and CEO of Jenkz Innovation and Design Group, engaged Direct Dimensions for a unique 3D project. As a Chrysler 300 car owner, he had been interested in purchasing an aftermarket accessory to enhance the vehicle’s front grille. After an exhaustive search, he found that what he wanted did not exist on the market. So being an inventor and entrepreneur, Mr. Jenkins decided to patent and design the accessory himself.



While Mr. Jenkins knew how he wanted his finished product to look, he needed extremely accurate data of the car’s grille area to complete the design. He also needed assistance in getting a prototype created, and eventually engineers who could work closely with his production facility.

After consulting with the staff at Direct Dimensions about the project and understanding how Mr. Jenkins intended to actually fabricate the piece, the engineers opted to use a Faro Arm and Faro Laser Line Scanner to capture the data with an accuracy of +/-0.002”. Mr. Jenkins drove his Chrysler 300 to Direct Dimensions’ lab where it was scanned in just a few hours.



With the precise dimensions and complex contours of the Chrysler 300’s existing grill accurately captured, Mr. Jenkins outlined his concept design for the trim accessory so that it would fit perfectly with the other front trim pieces. Using Rapidform’s unique XOR software for design-intent reverse engineering, a digital model of what would eventually be called the Chrome Mustache™ was created to Mr. Jenkins' specifications.




Once the design team finished the CAD model, this data was transferred to our in-house replication services team to manage the rapid prototype process. Prototypes were then created using stereolithography (SLA), an additive process that uses a laser and liquid resin to layer plastic. A final prototype was then chrome-plated to approximate the anticipated finished product. Although only a prototype, it looked and functioned like a real production part.



Mr. Jenkins then used the prototype, 3D CAD file, and help from the engineers at Direct Dimensions to arrange for the creation of a plastic injection mold. When the production facility had questions or potential problems, the DDI engineers were able to collaborate with them to make minor design changes or answer questions.

The “Chrome Mustache™” is currently available for sale. You can find it at dealerships and distributors across the USA and Canada, or at its website: www.naked300.com

Case Study: Reverse Engineering WWII Jeep Frame

DDI Vintage Jeep Frame Presentation 2008

View more presentations from dirdim.

Recently, Direct Dimensions had the unique opportunity to scan a 1940’s Bantam Jeep underframe. The Bantam BRC-40, alongside models like the Willys MA and the Ford GP, were among the first Jeeps produced by the U.S. Army. Due to their extensive use in WWII, they quickly became iconic of the war and of the era in general.

This particular Bantam frame, provided by client Todd Paisley, posed a challenging 3D problem, as it had rusted and corroded to the point where it was no longer usable. Direct Dimensions was brought in to reverse engineer the component in order to produce a digital model upon which new underframes could be manufactured.

DDI engineers Michael Lent and John Kelbel completed the scan in one day using a 12’ Platinum FARO Arm paired with the Laser Design SLP 2000 laser line scanner. The SLP 2000 proved ideal for this challenge, as its dual cameras and wide laser range reduce scanning passes, saving time while still ensuring high accuracy.

According to John Kelbel, the heavily warped underframe was scanned in sections from two separate positions, both from the front of the frame and from the back. These scans were then digitally combined using Rapidform software. Using Rapidform XOR software, the data taken from the scan was reverse engineered to produce a CAD model of the original ‘design-intent’ of this part suitable for manufacturing. The final deliverable allows the production of components based upon the historic Bantam underframe for several generations of Jeeps to come.

You can see additional documentation on the Jeep Reverse Engineering Project, including an interactive 3D model on our website.

Direct Dimensions in 3D Artist Magazine

At Direct Dimensions we have an extensive toolbox of hardware, software and skill sets that we are constantly adding to. One of our top digital modelers, Dan Haga, has been exploring the functionality of Rhino 4.0 with the Pointools plug in to make a model of a Lamborghini Reventon.

The Lamborghini Reventon project caught the eye of the staff at 3D Artist Magazine and they featured the project and Dan in the "Work in Progress" section of their most recent issue.

Click Here to read the article.

PBS Motorweek Talks Biodiesel

Direct Dimensions' work with Biodiesel University was featured on the PBS series "Motorweek." Direct Dimensions laser scanned and digitally modeled the bus interior to help Biodiesel University visualize the space planning of the Mobile Lab.

This episode reported on the alternative renewable fuel biodiesel. Other episode highlights include an "apple seed" hot water tank conversion, a local biodiesel co-op, and an overview of what biodiesel fuel can do, and why "homebrews" feel it's an important step in moving away from traditional fossil fuels.

You can see our Animated Walkthrough around minute 3:25 of the video!

More about Biodiesel University here.

View our Biodiesel University Featured Project here.

The full segment will air again this Thursday March 19 at 8pm on PBS and MPT.