Advanced surfacing creates a better socket holder

Stuart Anders, president of Allied Industries, used a 3D CAD program with advanced surfacing capabilities to design a better method for storing sockets which had already sold a million at Sears

Stuart Anders, president of Allied Industries, used a 3D CAD program with advanced surfacing capabilities to design a better method for storing sockets that Sears has already sold one million of as part of its Craftsman tool line.

Anders' design uses the same ball and spring mechanism that holds a socket to a wrench, yet his device is made of plastic rather than metal, minimizing the price.

The CAD software, Vellum 3D from Ashlar-Vellum, Austin, Texas, was key to Anders' ability to adapt the ball and spring concept for injection molding.

The software's surface creation tools allowed him to model an undercut in the mold design that allows insertion of the ball into the plastic part.

"This shape would have been very difficult to model in most CAD programs," says Anders.

"And while this project was my first use of Vellum, the program is so user-friendly that I was working on the ball and spring mold design after spending only a half day with the tutorial." Anders founded Allied Industries, which is located in Madison, Wisconsin, after a varied career as first a high school industrial arts teacher, then an Army helicopter pilot, and later a stint designing leotards and swimwear.

His father had a woodworking shop and Anders learned at an early age that he liked to invent things.

His first foray into consumer products was a very popular children's toy called Slap Wrap, a fabric-coated spring that a child wears as a bracelet.

The experience was valuable for Anders in that in taught him all the steps involved in turning an idea for a consumer product into a marketable item.

He founded Allied Industries as a way of formally pursuing this process.

Starting with CAD Anders purchased his first computer seven years ago.

As soon as he got it, he knew he wanted to use it as a design tool.

He also knew that 2D CAD was not for him.

"Two dimensional views were never very useful to me in the creative process," Anders explains.

"When you're creating something, you're not copying anything.

You're bringing what is in your imagination onto the screen.

It is much easier for me to do this in 3D because it lets me see the design from any angle, and lets me move things around and see how different pieces fit." The company that sold Anders his computer gave him a demo copy of Vellum 3D.

He found this program to be perfectly compatible with his desire to work in 3D because unlike many other 3D CAD programs, Vellum allows the designer to work in the z axis as he creates a model.

Rather than drawing lines in front, top, and side views as in other programs, the user simply draws the design in Vellum's Trimetric view, which is similar to sketching it on paper.

Another feature that sold Anders on Vellum was its surface modeling.

This program differs from other mid-range CAD systems in that it includes a strong surface modeling capability.

Most of the others do not offer surface modeling, or are just starting to include some rudimentary surfacing functionality.

"My designs use a lot of artistic, flowing shapes," Anders explains.

"I thought I was going to have to pay ten or twenty thousand dollars for a high-end CAD system to get the kind of surface modeling functionality I wanted.

That was more than I wanted to spend, and the learning curve on those programs is tremendous.

I was thrilled when I saw the surfacing capabilities of Vellum." Anders' idea for a new storage method came to him the way many good ideas do ? he was unhappy with his existing socket holder and figured there had to be a better way.

The socket holder he was using at the time consisted of bell-shaped metal clips positioned a stamped metal rail.

To attach a socket to the holder, the user must force it down onto the metal clip.

Since the size of the metal clip is slightly larger than the interior diameter of the socket, a friction fit is established when the socket is pushed down, holding the socket in place.

The problem with this approach is that the metal clip can rust, and if it is pushed or pulled to one side, it collapses and the sockets no longer fit tightly.

Anders' idea of using the same ball and spring method that holds a socket to the wrench, but done in plastic, would solve these problems by providing a secure fit that won't degrade over time due to rust or deformation.

Concept to Injection Mold Since his socket holder was going to be plastic, Anders had to work out how the ball and spring mechanism would be realized in an injection-molded part.

He developed the concept in Vellum, working in 3D from the beginning.

He found it easy to understand the functions of the software's different icons, and when he selected one, the cursor became context-sensitive.

Selecting the icon that creates a circle, for example, changed the cursor from an arrow to a circle.

Once he had selected a command, a line on at the top of screen walked him through how to implement the command.

Anders also made frequent use of the software's patented feature called Drafting Assistant.

By automatically identifying relationships such as endpoints, midpoints, center points, tangencies, and real and extended intersections, Drafting Assistant made it easy for him to move objects around and try different design configurations.

"If I wanted to put a circle in the middle of a square, I just highlighted the circle and dragged it to the square," he explains.

"When it was near the midpoint of the square, Drafting Assistant asked me if that's where I wanted to place the circle.

After I answered yes, the software positioned the circle exactly where I wanted it.

With other programs, that same operation would have taken more than 10 keystrokes, including steps like drawing diagonal lines through the square to find the midpoint.

Vellum keeps the creative process flowing by sparing you from tasks like that." Anders took advantage of the nature of plastic to deform under pressure in the design of the socket holder, eliminating a manufacturing step and cutting down on the product's cost.

In the typical metal ball and spring arrangement, a metal swedge surrounds the top of the hole that the ball fits into.

"I eliminated swedging by taking advantage of what would normally be a disadvantage of plastic.

By scoring a slight undercut into the core pin that is used to form the hole, I made the outside of the hole slightly smaller than diameter of the ball," Anders explains.

"After I drop the spring into the hole, I just set the ball on top of hole and snap it past the undercut.

The undercut deforms inward until the ball clears, then comes back to its original shape and holds the ball in place." Anders had no difficulty modeling the precise curvature of the undercut and then blending it into the cylinder that formed the hole.

"Vellum uses the same interface whether you're working with lines, primitives, or surfaces, and it's easy to mix and match elements to create the shape you want," he explains.

"This is one of the reasons I was able to model this rather complex mold design even though I had very little experience with the software." Anders recently upgraded to Vellum Solids (since renamed Cobalt (superscript: TM )) for its solid modeling and rendering capabilities.

He is using this program as he modifies the socket holder for new customers.

Vellum Solids features the same unified working environment as the basic 3D program.

All tools are always accessible on one of three palettes: the basic drawing palette, the surface modeling palette, and the solid modeling palette.

"Vellum Solids gives me the speed of working with solids yet I still have the extensive surface modeling capabilities for creating artistic flowing shapes," Anders says.

"I often blend surfaces onto a solid to generate a concept." He uses the software's photorealistic rendering capability to create images showing the socket holder embellished with a prospective customer's logo.

"Instead of spending several thousand dollars to cut temporary molds showing the logo, we create a rendering in Vellum and print it on a color printer," says Anders.

"This has helped us acquire several customers for spin-offs of the socket holder." To call Anders' first use of CAD a success would be an understatement.

Sears has already sold more 1,000,000 of the patented socket holders.

Anders' better idea was obviously much better, and a big part in bringing it to reality was his CAD software.

The fact that Vellum is easy and intuitive to use helped Anders define the concept, while the powerful modeling functionality put no bars on his imagination.

"Vellum is unique in the way lets you create models by melding lines, surfaces, and solids," Anders adds.

"It is perfectly suited to the way I work.".

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