Continuing on from the last blog about automation, let’s think about flexibility in programming.  CAM systems with little automation often have the advantage of maximum flexibility as the user can produce exactly the toolpath he wants. Taken to an extreme, you are back with manual programming, working out the coordinates for each tool position and adding G codes, speeds and feeds.

Obviously, the tradeoff is how difficult it is to achieve what you want. Where a lot of input is required by the CAM programmer, he (and very occasionally, she…) has to make many decisions as he prepares the CNC code. Results then depend on the skill of the user and also the amount of time available. For 5-axis programming, it is probably safe to say that it is virtually impossible to do this manually. Even for relatively simple 2D and 3D work manual programming can be very time consuming with some CAM software packages, making part manufacture uneconomical. What’s more, all the manual input and decision making is a possible source of error, making on-machine prove out an essential part of the process. Even worse, the CNC code produced may well need editing before it can run on the machine, introducing more potential problems.

For highly automated systems the decision making element is removed, but in some cases the methodology is so simplified that, although it is created quickly, the resulting toolpath misses out on best practice, with problems such as air cutting, overloaded tools, potential collisions and poor cutting conditions which can result in broken cutters or poor surface finishes.

Automated CAM software which is based on years of experience and R&D considers all these factors, checking for interference, avoiding over engagement of the tool, using climb milling where possible, and optimizing cutting speeds. It is like having your own expert programmer in a box, making it easy to get the benefit of the years of experience with one mouse click. Even better, systems like this give engineers tools to interactively edit the automated toolpath, so if they want to optimize it even more, they have the power to do so, giving users the best of both worlds.

Automation part 3 will look at the challenge of getting enough skilled people and how automation can help.