Working with lots of different CAD systems

Working with lots of different CAD systems – for subcontractors and suppliers this can be a real headache and especially if you are working with automotive or aerospace customers that use some of the high-end CAD packages.

In some cases there is no alternative to actually installing one of these CAD systems and employing a very expensive design engineer to run it, which can be justified if the majority your work is in the one market sector and you have to actively participate in the customer’s design process.

Thankfully for most people, CAD translation has moved on enough to make this unnecessary. For CAM systems neutral formats such as IGES and STEP or direct translators for products like CATIA, SolidWorks and Inventor are very reliable, enabling manufacturers to accept data from many different sources without a problem.

Once you have accepted that translators are OK, you can then choose the best CAM system for your application. Even if you have had to install the high-end CAD, transfer of model data is generally one way into the CAM system, so even for these applications a specialist, best of breed, CAM package will provide the best solution, reducing cycle times, improving quality and reducing tool breakage – real tangible savings.

Feature recognition – why?

For applications such as the manufacture of progressive stamping tools, there can frequently be large numbers of holes in the design to accommodate punches, dies strippers and guides. To make matters more complicated, the holes need to line up perfectly in each part of tool, so a small error in hole positioning can be disastrous.

If the tool is produced in a CAD system, lining up the holes during the design process is relatively straightforward. However, the problems arise when that information is transferred to the CAM software for CNC machining. Hole types require different machining sequences, while hole sizes and positions need to be interpreted accurately and reliably.

Without feature recognition there is a significant opportunity for human error. The position might be right, but the hole size or type could be wrong, or the hole could be missed altogether.

Feature recognition relies on defining the holes in the correct way in the CAD system. With a little discipline during the design phase, each hole can be identified for size and type as well as position. The CAM system can automatically pick up this information, ensuring the machining operations are correct and complete. Even better, the programming is much faster as automation of hole drilling, reaming, counterboring, tapping etc. will produce consistent machined results for every part with little effort from the CNC programmer. 

Click here to read how Feature Recognition sped up hole programming by 90% for a U.S. toolmaker.

Reliability, the first pillar of CAM

Recently we were involved in a conversation with a company that sells milling machines. As the story was related to me, a particular shop that was a customer and user of the milling machine had recently damaged some tool, holders and possibly their spindle. Upon further investigation, it seemed that their CAM software (which was definitely not WorkNC) had created a move which violated the geometry, and caused a crash.

Back in the early 1990′s, one of the biggest issues when using CAM software to program a part was reliability. Reliable cutterpath, without violations, is critical to successful machining. If the CAM software did not make reliable, gouge free, cutterpaths, then the user had to spend considerable time fixing the cutterpath so that it could be run, often leaving a milling machine idle as the toolpath was corrected.

There have been many advancements in CAM software, but the need for reliable cutterpath has not changed. We consider this as one of the main pillars, possibly the most important part, of CAM machining. This becomes especially important as you move into unattended machining, or more automated machining processes, such as dental machining. When dealing with dental restorations, every dental piece being machined is unique, yet the software must work reliably, and create good cutterpath, every time. Fortunately WorkNC has a reputation of providing reliable cutterpaths.

What do you think are the most important aspects of CAM software? Where do you rate reliability? Tell us in the comments below.