There is often a trend by some CNC machine tool manufacturers, in any market sector, to push a complete integrated CAM software and hardware solution. While this does provide the customer with a single point of reference there are many hidden pitfalls; it can often be considerably more expensive in the long run and can also be restrictive when the company looks to buy new equipment in the future.

Companies that are purchasing new CNC cutting machines for the first time may not be familiar with the options available to them. They will no doubt review a selection of machines, each supplied with a recommended CAM system, and may not spend the time to correctly assess whether the software is the right solution for the hardware.

The main function of the CAM software from the machine’s perspective is to generate good quality NC code to tell the machine how to function. However, this is not the only purpose of CAM software – a good CAM system needs to be able to:

• Import a variety of CAD formats, and be able to intelligently clean ‘dirty’ files
• Provide easy and functional ways of applying cutting information to the part
• Nest parts efficiently, which can provide significant material savings
• Optimise the cutting path, which can deliver substantial reductions in job runtime
• Integrate with legacy data systems such as MRP
• Supporting many different machines (and maybe also other cutting technologies, such as routing) as opposed to just one machine supplier
• Must be easy to use, manageable and scalable

The biggest issue is that vendor branded CAM software will almost always only drive that particular brand of machine, and may also only be limited to one cutting technology (e.g. knife cutting, routing, laser etc). If your business expands and you decide to buy more machines you will then be either forced to buy the same machine brand in order to maintain compatibility for your CAM generated parts or you will have to run two CAM systems, which in itself opens up a whole ream of new problems; staff training becomes fragmented, with some staff knowing/preferring one system over another, and it may be difficult or even impossible to move jobs between machines.

Tricks of the trade
CAM software is a ‘value added’ product for a machine tool, yet the machine cannot be driven without it. Vendors will often use the software as part of a discounting structure – ‘buy the machine and we’ll give you the software’ – this often appears like a not-to-be-missed deal, but often equates to less than 1% percent off the overall price. This can also affect the ongoing maintenance costs, as hardware maintenance is generally considerably more than software maintenance, so you end up paying extra year on year.
A machine tool vendor may quote an ‘integrated’ solution, but this integration is often only between the CAM software and machine tool, which you would expect anyway. True integration, and subsequently automation comes when your CAM system can communicate seamlessly with all applications that need to interface to it, including any CAD systems, machine monitoring equipment and your MRP or ERP system.

Performance and usability are also key factors. A cheap but cumbersome system will quickly cost you more in man hours if all but the simplest tasks take time. Compare common tasks such as importing/cleaning a CAD file, applying tooling, nesting and generating NC code. A CAM system should save you in three key areas – programming time, machine runtime and material utilisation. If you can automate common tasks then programming time will be minimal. Machine runtime is also a considerable factor. No doubt you know what your machine/staff cost to run per hour – compare NC code from your selected CAM systems by running them on the machine to see if there is a significant different in run time. Features such as common line cutting and optimised sequencing can shave hours per week off your machine runtime, allowing significantly more throughput. Finally material efficiency is becoming more important, especially with many composite materials costing upwards of €100 per square metre. Even a 1-2% difference can yield savings of thousands of Euros.

Know your rights during pre-sales discussions
Buyers are often pressured by manufacturers into purchasing a complete solution, with veiled threats being made that only the manufacturer’s software is able drive the machine, and that if any other software is used then this would invalidate the warranty. Both UK and EC competition law (Abuse of a dominant market position (Chapter II / Article 82 prohibition) prohibit businesses with significant market shares unfairly exploiting their strong market positions. This includes imposing unfair trading terms (e.g. exclusivity), refusal to supply or provide access to essential facilities and tying the customer in by specifying that if the buyer wishes to purchase one product they must also purchase all or some of their requirements for a second product. Companies found in breach of this law face stiff punishments. These include fines of up to 10% of their global turnover, court injunctions, law suits from third parties affected by such conduct and individuals being disqualified from being company directors.
Some more unscrupulous vendors have even said to customers that they are not concerned which CAM software is used after they have lost the original software sale, but have then reconfigured their machines once the software is installed in order to ensure that the user has problems, allowing them to go back and ‘solve’ them with their own brand product at additional cost.

CAM Buyer’s Checklist
When buying a CAM system you should ask yourself the following:

• Will I ever need to drive any other CNC cutting machine e.g. different brand or cutting technology? Having just one CAM system will drive your overall investment and support costs down. Are there postprocessors available, and are there existing machines using them? Talk to existing users to gauge satisfaction
• How does the Machine vendor’s nesting perform against other systems – multiply any percentage difference on your material spend per year to see how quickly it mounts up!
• Will the CAM system integrate with existing systems such as MRP?
• How long does it take to import a CAD file, apply profiling and nest the part in each system? Can you store multiple machining information on one part? What happens to all the nests containing a part if the part design changes?
• Support is important, especially if you have different machines/technologies. Only deal with companies that have experience driving all the technologies you need supported.

Summary
When compared to the price of a new machine tool, CAM software appears relatively insignificant but is much more a value added product then is currently recognised today. Granted, a machine vendor’s CAM software offers an element of perceived security that everything will work, but programming a CNC machine is not rocket science. What is complex is the linking of all (different) elements of the manufacturing chain, which only a dedicated CAM manufacturer has a vested interest in providing. Many CAM companies sell systems to customers after the initial machine/CAM purchase, usually once the user has spent a small fortune discovering all of the pitfalls mentioned above. You can save yourself the time, hassle and cost in advance by doing your homework before you buy. Check that the CAM provider is already driving the machine brand you are looking to buy. If a machine tool vendor states it will not support other software before they’ve even sold to you then that should ring alarm bells. With any purchase such as this you should be looking for as open a system as possible, giving you greater choices in the future.

About the Author/Company:
Martin Bailey is the Marketing Manager for JETCAM International, and is also the author of several marketing and technology sector books. JETCAM Expert is used in over 7000 locations worldwide and supports virtually all profiling, punching and routing CNC machines in the sheet metal, aerospace/automotive and other industries.
For more information visit www.jetcam.com.