Why do machine shops need a CAD system?

Jan. 5, 2009
By Mark Driscoll, OEM Business Development Manager Dassault Systmes SolidWorks Corp. The machine shop at DEKA Research and Development Corp. received this part model from its Engineering Department. (Image courtesy of DEKA Research ...

By Mark Driscoll, OEM Business Development Manager Dassault Systmes SolidWorks Corp.

The machine shop at DEKA Research and Development Corp. received this part model from its Engineering Department. (Image courtesy of DEKA Research and Development Corp.)
Because toolmakers at DEKA Research and Development Corp. use SolidWorks 3D CAD software, they were able to create the fixture to produce the part in less than 45 min. (Image courtesy of DEKA Research and Development Corp.)
This image shows the DEKA Research and Development Corp. part nesting in the fixture. (Image courtesy of DEKA Research and Development Corp.)

Amid intensifying global competition, machine shops are searching for ways to automate processes, compress delivery times, and reduce costs.

For many years, computer-aided manufacturing (CAM) applications have been the mainstays for tooling, machining, and manufacturing operations, and continue to drive tool-path programming for CNC machining.

However, in today’s market, machine shops are looking for additional technology enhancements to improve productivity.

Faced with growing demand for shorter lead times and increasing pressure on pricing, manufacturing operations need to shake time and cost out of the process to succeed in an increasingly competitive market.

In this environment, machine shops are turning to 3D computer-aided design (CAD) technology to overcome these challenges. There are many reasons why today’s manufacturing operations need a 3D CAD system, a range of important features to look for when evaluating a CAD package, and real, tangible benefits for manufacturing organizations that make a prudent choice.

Why machine shops need CAD
Machine shops need a 3D CAD system because they can no longer spend time and incur costs in processing customer geometry, nor in creating tooling, programming CNC code, or iterating with customers. A 3D CAD system can more efficiently and cost-effectively provide:

Improved handling of part models – With a 3D CAD system, machine shops can import, repair, and work with a variety of design data. Part designers often attach metadata to 3D models to dimension features and establish geometric tolerances. With a CAD package, machinists can utilize this data to interrogate the part and assess its manufacturability. Improved handling of part models not only saves time but also enhances accuracy and reduces waste, scrap, and rework.

Automation of design changes – Design changes occur without fail, either because a change required by the designer – such as an engineering change order – or because the machine shop needs to address a production problem. In either case, a 3D CAD system automates the process of changing the model and re-programming the tool path in the CAM system, especially when the CAD system and the CAM package are fully integrated.

Using the SolidWorks 3D CAD system, toolmakers at Longmont Machining, Inc. can quickly get answers to questions.(Image courtesy of Longmont Machining, Inc.)

Better communication of changes/ production issues – Whenever a machine shop has to make a design change to resolve a production issue – such as increasing the wall thickness of a part that is too thin for injectionmolding – a 3D CAD system makes it easier to communicate the reason for the change to the customer.

Enhanced jig and fixture design – With a 3D CAD program, machinists can use the part model to design the manufacturing environment, including jigs, chucks, and fixturing, directly on the part. This capability ensures that machinists select the right tool or develop the right fixturing for a particular part. A 3D CAD system also provides functionality for downloading standard component models online and developing the exact tooling required for a particular job.

Specific tools for creating mold components – Some 3D CAD packages include tools that make it easier to create mold components – including core and cavity, sliders, ejectors, runners, etc. Machine shops can use additional tools to evaluate and change draft angles, surfaces, and wall thicknesses, as well as position parting lines appropriately.

Tooling created with the SolidWorks 3D CAD system. (Image courtesy of Longmont Machining, Inc.)

What to look for in a CAD system
To obtain maximum benefits from a 3D CAD system, machine shops should look for the following functionality when assessing available systems:

Ease of use – Is the CAD package easy to use? Most machinists will not use a CAD system as frequently as a designer, so it has to be intuitive.

Broad data import/export capabilities – Can the CAD package import/export most major file formats, such as IGES, STEP, ParaSolid, and DWG? Does the system include translators/converters for bringing in other CAD formats?

Surfacing and geometry manipulation tools – Does the CAD system include tools for manipulating and repairing imported geometry, such as feature-recognition and surface-patching capabilities?

Direct CAD/CAM integration and full associativity – Is the CAD system directly integrated with a CAM package? Does the CAM system import the CAD model to create tool paths or does it use the actual CAD system as its modeler and maintain full associativity between the design and machined model.

Model evaluation and interrogation features – Does the CAD package include capabilities for evaluating the manufacturability of the part, such as draft analysis, interference detection, and design for manufacturability tools?

Design configuration capabilities – Does the CAD package have design configuration capabilities so machinists can automatically create variations in tooling to accommodate part variations from the base design?

The SolidWorks 3D CAD system helps Longmont Machining develop more complex tooling. (Image courtesy of Longmont Machining, Inc.)

Tools for design communication – Does the CAD package have design communication tools that make it easy to share 3D models with customers?

Real-world benefits from CAD
Machine shops that have embraced 3D CAD technology are realizing real benefits. All 15 machinists at DEKA Research and Development Corp. in Manchester, N.H., use SolidWorks 3D CAD software, which is fully integrated with the SolidCAM CAM package. According to Dennis Waite, shop manager at DEKA Research and Development Corp., having an integrated CAD package has become a necessity for his operation.

“We simply have to have a CAD system – not only to analyze radii, determine what size end mills to use, and replace missing surfaces but also to have the ability to make design changes and generate new tooling automatically,” Waite said.

“The geometry manipulation capabilities in a 3D CAD system are so much more powerful that we are more efficient whenever we need to modify a part. A CAD system saves time and effort, and now that we use it to drive our operation, we would be hard-pressed to do it any other way.”

At Longmont Machining, Inc. in Longmont, Colo., which also uses the integrated combination of SolidWorks 3D CAD and SolidCAM CAM software, using a 3D CAD system is paying dividends in several areas.

“Because the CAD and CAM systems are joined together, generating and updating tool paths is much easier,” Robert Laverentz, manufacturing engineer, said.

“There is no need for extra programming or extra translations, which saves time, and the integrated approach seems almost effortless compared to when we did not have a CAD system,” he added.

Dietrich Bertschi, production manager at Longmont Machining, said that a CAD package also extends the shop’s capacity for designing its own fixturing.

“We do a lot of value-added machining on molded parts that have no flat surfaces. In those cases, it’s critical that we have a CAD system that has mold and surfacing tools so we can design fixturing around the model itself,” Bertschi said.

At NCAD Products, Inc. in Oviedo, Fla., which uses the integrated combination of SolidWorks CAD and CAMWorks CAM software, CAD/ CAM integration enabled the company to expand its business and add machining capabilities, according to owner Neil Porter.

“The efficiencies provided by CAD/ CAM integration allowed us to grow into a full-service job shop. If machining was not so well-integrated with CAD, we simply would not be doing it. All datums are relative to one another, so what you see is what you get. If the design changes and I need to stretch a part by 0.01 in., for example, it’s easy to make the change to the CAD model, which is associated with the CAM package, and start generating new parts,” Porter said.

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