Extreme Precision of 3D Laser Scanning used
for “Extreme” Shoe Project

The Company:

A custom jewelry design company with high-profile customers required the high precision of laser scanning to create a unique piece for a unique customer.  The customer, a professional athlete with his own line of shoes, wanted to make exact replicas to 1/10 scale of all of his shoes, and string them together into a unique solid gold necklace.

In early 2006, the jewelry designer tried using an artist to create a tiny version of each shoe, but the creations came up short as far as detail, complexity, and accuracy were concerned.  He needed a way to insure absolute fidelity to the design, down to the stitching.

The jewelry design company had heard of noncontact laser scanning, and searched the Internet for companies that provided the service.  When they found the GKS website, the designer contacted Larry Carlberg at GKS, a division of Laser Design, Inc., in Minneapolis, MN.  The designer was impressed with Carlberg’s knowledge and expertise.  GKS maintains several Laser Design scanners, so the appropriate size and resolution was readily available. With over 25 years in the business, GKS metrologists have experience with all kinds of unusual custom projects, and Carlberg was able to create a plan to implement the complicated multi-step jewelry project quickly and within budget.

At first the jewelry designer sent only one shoe to be laser scanned with Laser Design’s high-speed, high-accuracy RPS-450 Laser Probe to see if the results lived up to his exacting standards.  Carlberg used the RPS-450 because it has the best depth of field and accuracy of ±.002 inches.  When the resulting files were scaled down in size, the error was minimized proportionately.

The professional athlete only had one pair of each of his special shoes from the past collections, so he had to be sure that the scanning process would not ruin the shoes in any way.  Since the laser scanning system projects a line of laser light onto surfaces while cameras continuously triangulate the changing distance and profile of the laser line as it sweeps along, the problem of marring the surface or depressing the soft parts of the shoe was eliminated.  The system measured fine details and captured complex freeform geometry so that the object could be exactly replicated. Laser scanners quickly measure articles, picking up tens of thousands of points per second, and generating huge numbers of data points without the need for templates or fixtures.

To get better quality data, Carlberg explained that they would use some powder on the surface to make it more readable by the laser, but other than that, the shoes would remain undamaged.  Once the designer saw the results of the first shoe’s scanning, he was sold.  “The results were absolutely perfect, down to the laces, down to the thread on the shoes, and the pattern of the soles.”

The process continued until Carlberg had scanned all 14 shoe styles, which happened over the span of 3 ½ months. Some areas of the shoes were more difficult to scan than others, for example, the laces and inside the shoe.  “Our expert technicians were able to  develop an excellent process using Geomagic to minimize the errors incurred by geometry that is not captured completely around, such as the laces and the back straps, so that the entire area is represented on the STL models made for the jeweler,” explained Carlberg.  After each shoe model was scanned, the designer carefully checked the STL file, and did not find any flaws.

Small wax figurine rapid prototypes were created for every shoe, from which a mold was made.  From the tiny, precise, meticulous molds, solid gold shoes were cast, links were added to the toes and heels, and the 1 ½-inch shoe “charms” were assembled into a necklace. 

The Results:

“The whole project was fun, even when we had a couple of rush jobs,” said the jewelry designer.  “Larry at GKS was a thorough professional, walking me through the scanning process step by step, no pun intended.”  The solution created by Carlberg using the Laser Design RPS-450 stayed within the set budget.

“Each shoe design posed slightly different challenges in capturing the details, but GKS laser scanning was the perfect solution.  The data was very accurate and allowed us to create molds that were exact reproductions of the shoes themselves, which is our client wanted.  The client was absolutely thrilled with the results, and has worn the necklace on MTV as well as at an ESPN awards ceremony.  The piece has also appeared on the cover of magazines.  We were not able to get the precise results we wanted with traditional ‘artistic’ means.  The professional laser scanning at GKS exceeded my expectations.”