Although there are dozens of CAM systems available, choosing one is not as difficult as many believe. It comes down to choosing the best one for your application. This paper is meant to help give you the tools to help pick the best one for you.
Consider the packaging
CAM software is available in three different configurations. Fully integrated CAD/CAM, CAM packages with some CAD and CAM only.
1. Fully integrated CAD/CAM packages. In this package, the CAM software is integrated within the CAD design software used by the design departments. Because it is integrated in a full design package, it often includes design functions not found in other Cam packages such as; dimensioning, plotting, bill of materials, solid modeling, surface modeling, assemblies and of course an integrated CAM solution.
2. CAM packages with some CAD capabilities are the next configuration. These are typically marketed as CAM systems but include many CAD functions necessary for manufacture. These systems may have the ability to create and edit wireframe, surface and solid models – but may not have all of the advanced design tools available in a full CAD/CAM package.
3. CAM only packages have a precision focus only on CAM. Their software only creates cutterpaths for CNC machines and has only minimalist design functions for things like creating boundaries.
Pro’s and con’s of the approaches to consider are:
Fully integrated CAD/CAM system
- One single design to manufacturing workflow
- Full CAD functionality for editing parts, or modeling fixtures
- Often maintain associativity with the model
- Assembly functions allow for easy importation of fixtures, clamps, vises and tables
- Fewer interfaces and software to learn
- No data translation issues or concerns.
CAM packages with CAD capabilities
- May contain niche or special functionality not found in general purpose systems
- CAD functions geared towards manufacturing, such as electrode creation.
- Company is heavy CAM focused
CAM only packages
- Singular CAM focus
- Many packages are quite powerful
- Can be useful when designs are always ready to be milled.
Determine the Types of Parts You Will Be Milling
Once the types of parts that are being milled are determined, this information can be used to narrow down a product range. Most CAM milling packages fall into different categories of functionality, often dictated by the type of milling being performed.
- Drilling – hole boring, gun drill and coolant lines – typically uses canned cycles on your mill controller.
- Two-axis milling – where the CNC mill moves simultaneously in the X and Y directions but not in Z. Simple contouring and pocketing are offered here.
- Three-axis contouring – this can range from small, fairly simple pieces like a bracket for an engine mount to a very complex mold like an instrument panel dashboard of an automobile. Typically, the mill will move in X, Y and Z simultaneously. This form of milling is the most common.
- Five-axis milling – where the machine has some form of rotation ability – typically A, B and/or C – on top of the regular axis movements. If the rotations happen concurrently with the axis (XYZ) movements, it is referred to as simultaneous 5-axis. If the part rotates into position, then mills in three-axis, it is referred to as positional 5-axis.
- Also, one may need CAM functionality for non-milling machines such as lathes, wire EDM or laser cutters.
Different CAM products will be stronger at some types of milling than others. Consider whether you need automatic feature recognition for holes and pockets, or if you will program them separately. Perhaps your parts have no simple shapes, but are complex, free form shapes. You must determine which type of milling will be the most critical to your business, and concentrate on those CAM packages that fill those needs. Then, match up functionality in the CAM program with the type of parts you will mill.
Secondly, you also must consider future growth plans. It is not uncommon for companies to take on more complex data and milling as their skill level and experience increases. Although you may start by milling only simple prismatic 3-D parts, you may grow into milling complex 3-D data. CAM packages should provide a growth path for your milling needs.
Two common mistakes of CAM purchase decisions are buying too little software for your needs, or buying too much. If you buy too little, later you typically are forced to upgrade to a different package. If you buy too much, you may overpay and not use a majority of the features you spent money for. One common way that someone may buy too much is purchasing five-axis simultaneous software when it turns out that five-axis positional is faster, easier and less expensive and cuts the parts just as well.
Consider the Developer
The strength of a CAM product can be no greater than the strength of the developer. One needs to examine the developer and consider the following:
- How many developers and support staff are there for the product?
- Does the developer have the resources to continue development?
- How often are updates made available?
- Does the developer have staff that understand machining or have machining experience?
The quick tip here to purchase from a company that is knowledgeable in the product and will offer excellent support. One that has shown a long-term commitment to manufacturing and helping their customers. Truly, the Internet and e-mail has brought support closer to the end user than ever before.
One question that many people have is whether or not they can purchase software used from another shop. Most software companies – not just CAM companies – are either selling a subscription to the software or are selling a license to use the software. Generally, these licenses are non-transferable, and in most instances you will need written permission from the software manufacturer to transfer a software license. Find out for sure that the license can be transferred before making any decisions.
Determine the Types of Data to Mill
Will you be milling what you design in-house, or will you be loading data from customers for milling? When milling parts for a job-shop, there typically are different types of data that get milled. The simplest is 2-D wireframe data, followed by 3-D wireframe data, solid models, surface models and other specialized data such as scan data or point clouds. Often the types of data that you expect to mill will narrow down the CAM choices available.
If using outside data make sure that the prospective CAM system is capable of reliably reading in the data to be milled. If using an integrated CAD/CAM system, typically the data is drawn in the same environment. However, since many shops mill data given to them from another company and usually a different CAD system, you must consider the translators available. Many different options are available for reading in data formats such as DXF, IGES, STEP, STL, ACIS solids and Parasolids. When considering translators, think quality over quantity
You must consider whether these translators are included or extra cost, and how that affects the value of the CAM solution.
Determine in What Environment to Mill
From shop to shop, it is common to find CAM software being operated in different locations and in different processes. You should determine where the software will be operated and by which employees. Three common locations for CAM software operation are: the CAD department, the CAM department and the shop floor. Operation of the milling software within the CAD department allows for one engineering function within an organization to be responsible for design and manufacture. Depending on workload, this option may reduce the number of software licenses and computers needed. Also, since CAD operators are already computer literate, they typically learn the CAM software quickly. Often in this structure you will see the completely integrated CAD/CAM system being used.
The downside risk to the CAD department strategy is that many CAD designers are not experienced with actual milling operations. Additionally, frequent interruptions from the milling department to the CAD department can disrupt design productivity. Lastly, in a busy environment, the computer license can be “tied up” with CAD operations and unavailable for CAM.
Companies that use a separate CAM department generally use it as an interface between the CAD designers and the shop floor milling machines. CAM departments get the data files from the CAD department and program cutterpath for the shop floor to run. Often the persons running CAM software are experienced with machining operations. In this environment, you can find all three types of systems: Integrated CAD/CAM, CAM with some CAD and CAM only.
The disadvantages of using a CAM department are that it is an extra step in the process, logistically. CAM operators can be interrupted by both the CAD department and the shop floor with questions and changes.
Faster personal computers with lower prices and easy-to-use CAM software packages have allowed many businesses to place the CAM programming right on the shop floor. This allows the person who is most familiar with the milling machine and tooling to program their own cutterpaths. This strategy may allow for fewer interruptions of either department and generally allows for shorter leadtimes. Disadvantages of this method are that additional licenses and training may be required for the amount of work. Shop floor programming generally requires a CAM solution that is easy to use, and processes quickly.
Make Sure You Go for a Test Drive
This is the most important portion of choosing a CAM system. Perform a trial evaluation of the system and actually cut metal on the milling machines. Evaluating software on your own data, on your own schedule and with your own mills will help you to determine whether the whole package and process will work or not.
When trialing CAM software take the following into consideration:
- Try the software on the largest parts you may work on, to see how well the database handles larger data sets.
- Try the software on the smallest and finest parts you may work on, and check the surface finish and quality.
- If there were any parts from the past that were particularly difficult to program, try some of those.
- Check if there are post processors already available for your mills.
- Check and use online resources for training, such as YouTube videos, webinars and other online resources.
- Check and use online resources for support, such as forums. Check to see if they are active, and if people are getting answers to questions.
Selecting a CAM system does not have to be difficult. Start by deciding whether you want an fully integrated design to manufacturing solution, or are willing to have multiple systems. Next select one whose functionality matches the needs of your parts, then take it for a test drive. If that is successful, then you are most of the way to finishing your selection.