Design with CAD | CAD Integration

CAD capability bears fruit - computer-aided design

Belinda Jones

By being able to work closely with its customers' industrial designers and engineers, this shop helps customers improve the patterns and prototypes it machines for them. The value of this design input has made the shop a key manufacturing resource for a growing list of clients.

Like most shops involved with CNC machining, Apple Pattern finds the CAM part of CAD/CAM extremely important. CAM (computer-aided manufacturing) is virtually synonymous with "computer system for CNC tool path generation" for most of these users. But unlike a lot of shops that do CAD (computer-aided design) just because it's an inescapable part of what they need to do effective CAM, Apple Pattern saw the strategic value of CAD for its own sake, and is reaping some big benefits from giving its employees greater CAD capability. Not the least of those benefits is better machining.

A Model Shop

Apple Pattern is a model shop in Sterling, Massachusetts. It manufactures patterns and prototypes and has specialized in rapid prototyping--both in the service of producing prototypes very rapidly by whatever means, as well as in the specific technologies identified by this term, such as stereolithography. But NC machining has been a key part of its capabilities, so NC programming was a necessity. Hence, investing in a CAM system was easy to justify.

However, when Jack Haley, president of Apple Pattern, took a hard look at the direction of his company several years ago, he came to a fundamental insight. The shop could not remain in the business of making patterns, models, or prototypes, without automating the process. It had to get into the business of servicing its customers' special design needs. These design needs may very well require a CNC-machined pattern or a prototype produced by stereolithography, he realized, but most of all, it was knowledge and expertise that customers were looking for. It seemed to him that investing in CAD was the best way to develop the knowledge and expertise of his employees--and make this knowledge and expertise accessible to customers.

So in 1990, Mr. Haley made three key decisions based on this insight. He purchased 3D CAD software for all design work, he began to promote his company's "consulting" services, and he added CNC machining capability. This strategy paid off. His company grew from six to 22 employees and doubled revenues in two years. Neither just a pattern shop nor a design house, it has created a niche for itself and is prospering. But the pivot point for this turnaround has been the shop's CAD capability.

Today, Apple Pattern works closely with its customers' industrial designers and mechanical engineers to troubleshoot designs, discuss alternative prototyping methods, review tooling, and provide precision CAD data. CAD has helped the shop attract and keep high-caliber employees, whose attitude and first-rate service attract and keep good customers. And CAD offers the speed, accuracy, and data translators the shop needs for its rapid prototyping equipment and CNC machining centers.

Transitions

Jack Haley had his start as a foundry pattern maker and moved into machining work. In 1981, he started his own business in Leominster, Massachusetts. Mr. Haley soon realized that contract machining was declining in this area. He decided to move into creating tracing masters for mold makers, where some of the same skills were utilized, yet involved greater accuracy. From here, it was a natural progression to move into making model parts, rapid prototyping and short-run molds.

Another prominent figure at Apple Pattern is Ric Perry, senior sales engineer. Originally from the Detroit area, he worked throughout high school and college in the mold-making shop his father owned in the suburbs. His personal goal was to become proficient in CNC machining and programming, and then advance into the area of 3D surface machining.

Before joining Apple Pattern, he worked for a larger corporation as a manufacturing engineer. He focused mainly on plastic parts, but had experience in sheet metal and die casting. A manufacturing engineer for 12 years, he joins Jack Haley with the same dedication to supporting industrial and mechanical designers on part design and to helping bring their products to market in a timely fashion.

Introducing CAD

Apple Pattern entered the world of CAD in 1990, with four seats of Cadkey software from Cadkey, Inc. (Windsor, Connecticut). A fifth seat was purchased in 1992. One of the main reasons this software was chosen was the strength of its data translators, a feature the shop would need in order to work with design files from many sources. Cadkey is a 3D, PC-based system, so the hardware and software investment was not a major budget item. A much more crucial issue was the effect introducing CAD would have on the people on the shop floor.

Not long ago, many companies in the industry had the perception that a computer in the office would replace an employee. That was certainly not the case at Apple Pattern. Their employees realized CAD was a vital "tool" that would enable them to make a better job of the one they currently had and to grow on the job as the company expanded its business. Employee turnover has been extremely low and the company has been able to attract the new talent it has needed to maintain this growth.

Initially, all employees were invited to learn CAD and understand how it would effect the way they work in the future. Every one of their employees accepted the challenge and attended CAD training courses at night. A roving CAD system was placed on the shop floor and today, virtually every model maker on the floor can, at the very minimum, pull up a CAD database and generate a 2D tool path. Over half of the model makers can produce a tool path for 3D surface machining.

Employees train on new equipment and are encouraged to help each other to come up to speed. "The term model maker has taken on a new meaning," says Mr. Perry. "A few years ago it referred to a person who created aesthetic models. Now model makers are proving CAD databases and substantiating designs for manufacturability. It's a much higher level of service."

The Best Design, The Best Machining

Apple Pattern's business model is an engineering approach backed by the intent to offer not just a design, but the best design with rapid prototyping. As Mr. Haley sees it, "This is absolutely a service business. It's not just 'here's your model and on to the next project.'"

Mr. Perry adds, "You have to be committed to the industry. Just having an order come across Jack's desk for a master mold and ten copies is not enough. We want to get on the phone with the engineer and try to find out what they are attempting to accomplish. We can look at a project with ten parts in it and see that some of them should be CNC machined. Other parts must be fabricated and CNC machined or made with stereolithography. Each project heavily depends on part complexity, the geometry, and what the engineer is trying to achieve. It should be more of a team effort than merely a sales quote."

By proving out CAD design files, helping customers get past limitations, critiquing problems and reviewing tooling, their services go far beyond merely producing a model. Apple Pattern acts as a facilitator between design and manufacturing. For example, a designer at Apple was consulting with a customer on a few design modifications. The 3D model was brought up in CAD and the designer explained his proposed alteration to a corner radius of a part. He easily modified the surfaces and proceeded to shade the model for better visualization. The customer could clearly observe the improvement and authorized the change right on the spot.

Users at Apple Pattern report that editing in 3D is so easy that real-time changes with clients are extremely helpful in shortening the product development cycle. Mr. Perry remarks, "There's no excuse not to design in 3D with the price of personal computers and CAD software like this."

Since 1992, Apple Pattern has added eight CNC machines. Four of the machines are two-axis milling machines. The other four are three-axis milling machines. Because of this addition alone, companies who had not considered them in the past are sending them work today. This technology also enabled them to broaden their geographic market.

They receive data from a wide range of customers and CAD systems. Cadkey is their primary vehicle to read in CAD part files, prove the databases and transfer data into their PC-based CAM system (SurfCAM from Surfware Inc., San Fernando, California). With the Cadkey software, they verify part files by correcting geometry that does not properly connect, rebuild wireframe models for surface generation, and modify conditions that cause problems downstream in machining.

The company maintains a total of 12 personal computers that are fully networked in a client/server environment. Apple Pattern communicates with customers and transfers CAD part files through a high-speed modem. For key accounts, direct lines have been installed for faster response time.

Since enhancing its CAD capability, the shop has witnessed an interesting trend. Two years ago, 100 percent of their work was derived from blueprints. One year ago, half of their jobs came from prints, and the other half from computer diskettes. Today, 80-85 percent of their work comes in a CAD data format, and 50 percent of that work is transferred to their business via modern. In the past, Apple's customer base was geographically sensitive. Now, engineering data changes hands quickly and opportunities come from all over the globe.

Faster Designs

Equipping the model makers with CAD and getting them involved in the product design cycle early often means that a customer's product can go to market earlier than otherwise. A good example is a modem casing prototype created for Microcom, Inc., a company that develops and markets high-speed modems and other PC accessories. The manager of mechanical design at Microcom, Wayne Norwood, had the challenge of creating a new modem casing as part of a new product release.

An industrial design consulting firm, also a Cadkey user, was contracted to do the design. Because the casing had to house a printed circuit board and other internal electronics, with properly positioned hard switches and light-emitting diodes, the modem casing was essentially designed in 3D from the inside out.

In the very early stages of the project, the team at Apple Pattern met with the designers to discuss producibility, the design for the mold and possible changes in the prototype casing. The shop took the Cadkey part file, produced an IGES file, and read it into SurfCAM for tool path generation. Within two weeks, a CNC-machined master was produced and tested to see how well snap-fit features would work.

A few modifications were decided upon at that point. The casing master was also changed slightly so it could be used directly for a silicone rubber mold made from it. These changes facilitated the production of polyurethane prototypes. These polyurethane parts were used by Microcom's sales department for sneak-preview presentations to key overseas distributors. Meanwhile, their marketing department used other parts in photo sessions for data sheets, documentation, and promotional literature. They could also use the prototypes for packaging design. In the meantime, Mr. Norwood initiated regulatory testing of the electronics earlier than usual, confident that any emission problems would be disclosed in time for prototypes to be metallized or shielded and submitted for additional testing.

Mr. Norwood believes that his company gained a 12 to 20 week advantage by being able to "design out" problems using master models and prototypes to visualize the product far in advance of the release date. Working interactively with the model makers as part of the design effort helped get functional prototypes into the right hands early enough to exploit this time advantage.

Moldability

Another project recently taken on by Apple Pattern was a very complex lead paint detector gun, a product being developed by Radiation Monitoring Devices (RMD) of Watertown, Massachusetts. Paul Stoppel, engineering manager, contracted the design work and asked Apple Pattern to produce the prototype. The first round of prototyping was done in stereolithography. The part's complexity led to many changes. The model's wireframe geometry was originally constructed in Pro/Engineer, Parametric Technologies Corp., (Waltham, Massachusetts), then read into Cadkey using its IGES translator.

Alex Yawor was the model maker assigned to this project. Apple Pattern set up an initial meeting to discuss the moldability of the five parts that completed the design. Quickly, he was able to make a few suggestions that would result in a less expensive mold. Using CNC machining, Mr. Yawor made a master from ABS plastic. Another meeting was held to discuss the tooling and final changes. Mr. Yawor found a few undercuts and corrected those conditions. A large portion of his time was spent designing jigs in Cadkey that would hold the master for the remaining changes.

The final plastic prototype faithfully captured the sharp lines that stereolithography does not generate. "With a stereolithography part, you sometimes lose tolerances when you have to sand down the model. With a CNC-machined part, the precision is right on the money," noted Mr. Yawor.

"We had a continuous line into Paul Stoppel, the engineering manager at RMD and the designer on this project. This was one of our most complex projects," stated Mr. Yawor. "The organic shapes of the overall design gave us a few problems. There were 52 changes made on this part consisting of a couple of hundred surfaces. The client wanted all of the modifications on the CAD file to make sure the geometry was perfect for the mold maker."

Re-Engineering

At first glance, putting CAD tools in the hands of model makers and machinist may not seem a very likely way of improving the parts-making capability of a shop. For Apple Pattern, however, it re-defined the way they could service their customers. These CAD tools turned its model makers into service engineers, facilitating the prototyping process for both design shops and mold makers. In short, CAD allowed Apple Pattern to re-engineer their traditional processes, merging new and old technologies, and opened new market opportunities.