Choosing the Right CAM Software

Feb. 20, 2008
The money is in the model
“An example of SolidCAM running within SolidWorks making the transition from design to machine code generation simple and seamless.”

As the demand for more sophisticated and efficient machining increases, so does the need for more sophisticated computer aided manufacturing/machining (CAM) software.

Software that can reduce machining time significantly can increase machining productivity and profitability in the same way, and in today’s CNC-driven world, the right CAM software can be the difference between surviving and thriving.

However, if a shop manager considers only machining efficiency in selecting CAM software, he may be missing other profitmaking opportunities.

There are more than 40 CAM software packages on the market today.

Chances are that no matter how complex the machining requirements there are at least three or four packages, often many more, that will do the job in a reasonable amount of time.

There are several packages for every type and for every level of machining from entry level general machining to 5-axis, simultaneous multi-spindle, multi-tasking operations.

The decision on which CAM package to buy usually depends on what the shop’s personnel currently use, and what the machine tool distributor recommends. Too often, not enough consideration is given to how the software – and, especially, the part model used by the software – fits in with other shop requirements.

That’s where potential profit gets lost.

Consider the part model that’s used to drive the CAM software. Where did it come from, and where can it be used besides generating G-code?

In the best of all worlds, the part model created by the original designer is used directly throughout the entire manufacturing process. If communication between the designer and the customer uses the same part model, then the chance of miscommunication and incorrect or overlooked changes is reduced.

The same is true between the designer and the machine shop, between the machine shop and its suppliers, between the customer and its sales forces, and ultimately between the customer and their customers.

When conversion or translation of an original part model is done to accommodate the needs of a particular software package, that is where the time and the cost involved increase, and opportunities for miscommunication and other mistakes increase proportionally.

What this means is that if machine shop programmers have to convert, and rebuild customer part models, they run up unnecessary costs and they increase the chances that more costly mistakes will be made because of miscommunications or programmer errors.

Some CAM packages automatically convert a part model into their format, and claim to be 100 percent accurate in associating back to the original model. Even if that is true, it still means that at least two models for the same part must be maintained instead of one.

If any changes become necessary, then both models must be fully maintained so that all subsequent actions based on the part model remain accurate. That may not seem very significant until you think of the other tasks that a part’s model can be used for besides machining.

Start with the designer.

There is software available that tells a designer if features of the part he just designed are unnecessarily expensive to machine. The DFM product line from Geometric Software Solutions ( looks at a part model and, based on rules set up by the machine shop, tells the designer if there are features that are unnecessarily costly.

For example, a small radius filet at the bottom of a three-inch hole may need a $100 EDM operation to produce while a slightly larger radius could be done at a fraction of that cost.

Knowing that gives the designer an opportunity to take costs out of making that part, and eliminates the need for the machine shop operator to educate the designer and the customer on why making that hole as designed is so expensive.

And where does the quality control system get its measurement and tolerance information? Where does the ISO reporting software look for data? Which model is used to make workholding jigs and fixtures? How about automated package design and manufacturing after the part is made? Which model is used to generate sales literature? If all of the software that needs part information looks to the same model, then it is a lot more probable that all of that software will be working with the same latest and greatest data.

No time and no expense is needed to convert and verify the model to other models just to satisfy the needs of different software packages.

That brings us back to selecting a CAM software package.

Part models are originally created by computer aided design (CAD) software. In today’s world, CAD software needs to generate 3D solid models because anything less diminishes the overall productivity and profitability of the many people who will use the part model.

Many CAD and CAD/CAM packages generate 3D solid models, but use proprietary part modeling formats to do so. Other software that needs part information either accesses part data directly from the proprietary database, or converts the proprietary format into its own proprietary format.

The need to convert from one format to another is where the most difficulties arise. So, the more that a shop uses a single CAD modeling software format, the less time it will take to get work done.

One example of this is the SolidWorks CAD model format.

SolidWorks has worked with other software developers to enable other software to run directly under the control of its software, so it eliminates the need for more than one model for each part or assembly.

Several CAM developers such as SolidCAM have taken advantage of this opportunity to partner with SolidWorks, and to offer end users a truly seamless flow from the conception of a design through part machining and out-thedoor packaging.

SolidCAM bundles SolidWorks 3D CAD software with its CAM package for less money than a user would pay to buy both packages separately. SolidCAM also has an arrangement with Autodesk that enables the SolidCAM software to work directly with Autodesk Inventor models. This gives users a choice of which CAD software to use for their own operations. Not all software packages are that flexible.

There are several high-end software packages that provide a fully integrated CAD and CAM solution. Unigraphics, Cimatron, Desault’s Catia and Delcam’s PowerX for example.

The benefit to using these packages is that you have a one-source, fully integrated supplier for both CAD and CAM software in addition to whatever other software options the developers provide.

What this all means to shop operators that are considering the purchase of new CAM software or the upgrade of existing software is that they need to look at how the part model used by any given CAM package can be profitably used by other software packages.

These days, the cost of any software package usually is insignificant compared with the amount of profit it can generate.

Even so, operators need to look at all of the money that can be squeezed out of that part data because the money really is in the model.