When thinking of buying a CNC router, there are many things to take into consideration. One of the first things to do is take a hard look at what the machine will be expected to do. Too often woodworkers are lured by the technology and buy unnecessary options. Although most router vendors will promote the speed of their machines, overall speed will have nearly nothing to do with whether or not automation will be successful in a particular shop. Quality and ease of use will be much more important factors. Is the entire infrastructure available that will be needed to comply with this new technology? Are computers available in the office for CAD or CAM? What about suppliers for tooling? There are many things to think about when buying a CNC machine for the first time. Often these seemingly trivial details can balloon into nightmares. Better to deal with them early in the process.
Space is the one commodity that is often lacking (along with time). These machines not only take up a large footprint but one has to take into consideration other space uses such as raw material, finished parts, jigs and fixtures, and tooling. It is always a good idea to do a plant layout when introducing new technology into the manufacturing line. This exercise will help maximize the performance of the new equipment and the flow of the manufacturing process. As some of these machines weigh upwards of a few tons and are sensitive to vibration and movement, it will be imperative to check the load bearing capacity of the shop floor. It would not be recommended to install a heavy gauge steel framed, high performance router on the second floor of an old wooden building for example. On the other hand, a light gauge sheet metal low end machine would work perfectly well in this environment.
Electrical power is always an afterthought and it can be a costly one if overlooked. Check with an electrician to see if power requirements can be accommodated. Machines come in different voltages: 110, 220, 440, 600 volts and it’s useful to check the required amperage as well. It is always a good idea to have an electrician run the wires and the junction boxes before the machine is delivered so that the installation can be completed faster.
Compressed air capacity measured in cubic feet per minute (CFM) or metres cube per minute (m3/min) and pressure given in pounds per square inch (PSI) or kilopascals (kPa) are parameters that are readily stipulated by the machine manufacturers. It is important to check whether there is enough capacity in the plant’s system to accommodate the needs of this new equipment. Typically when a CNC machine runs out of air, it triggers a hard stop which results in lost time and perhaps damage to the part that it was cutting. It is not enough to have the capacity, but a good source of dry air will also ensure that the sensitive pneumatic and electronic equipment doesn’t corrode.
Is the vacuum system supplied and installed by the CNC vendor or is it the purchasers responsibility? Make sure that it will be designed to meet the company’s applications requirements and that it is compatible with the equipment.
Rethinking plant layout might be a good idea at this point since the introduction of automation will surely affect the fundamental operational flow. Equipment may have to be moved just to get the CNC machine to its final spot. Air ducts and dust collector pipes might also have to be re-routed. Check to make sure the machine will fit through the door or up the freight elevator. Making holes in exterior walls is always an expensive proposition but not unheard of.
Plant workflow will invariably change when a CNC machine is purchased. Not only will it affect the current plant layout and the routings of operations but Bill of Materials and any scheduling software may have to be modified to allow for the changes to workflow.
The inventory needed to operate the new CNC machine and the parts it will produce will be something to think about before the machine arrives. MDF spoilboards, cutting tools, maintenance parts and consumables are just a few of them. The cost of this extra inventory is something that is often overlooked in the equipment purchase decision process.
Talk to the tool supplier and if necessary, research other local suppliers. Also look at supplies of cutting equipment online as the savings on the price of the tool could offset the transportation costs. However, it is still wise to retain the services of a good local tool vendor who can sharpen tools and quickly procure some in emergencies.
The programming will preferably need to be done somewhere other than at the console of the machine. While some production shops can only afford to hire programmers part time or on contract, most will need an employee on site who can deal with last minute changes and custom programs.
Extra computer equipment will be required to do the drawing and the programming of parts. They will probably need to be networked and have access to the web. In smaller shops a diskette or a USB flash drive can be run between the office computer and the CNC machine but it is worth the cost of running a network cable. This will prevent the programmer from having to run back and forth to tweak programs or to make changes.
When moving to CNC technology, a shop will shift skills and become less reliant on skilled labour to machine parts as the skill of the person designing products and programming machines will become the key to success.
Training will become very important. Not only should the designer and programmer be up to date with the latest technology available but assemblers and other plant personnel must be trained to handle the increased output as efficiently as possible.
Can some of the work requiring a CNC machine be outsourced now? Or perhaps, once a machine is purchased, it might be used to perform some work for other shops in the area. It is a good idea to research this option because it could have an impact on the timing of the purchase of new equipment.
Most shops run low in dust collection capacity. CNC machines require a great deal of dust suction. As dust will affect the operation of this sensitive equipment, the quality of the work will suffer even more from a lack of dust collection. Consider purchasing a stand alone dust collector rated for the requirements of the machine if it is suspected the existing equipment will not suffice.
Who will operate this new piece of machinery? Although workers probably operate all the machinery in the shop when they need it, it’s probably not a good idea to leave the CNC open to universal abuse. In most shops there will be a dedicated operator for this machine. While it can be the owner of a small shop or the designer/ programmer in a mid-size shop who operates the machine, it’s a good idea to have one person responsible. Consider creating a protocol for the operator that includes maintenance, training, operation and safety.
There are many possible strategies for lining up work at this new work center. Chances are there is already a system in place for scheduling work in the shop. Spend some time to incorporate all the implications of this new technology into the organization.
If there is concern about quality and efficiency, then maintenance is the single most important item to consider doing properly in the future. There is no question that a well kept machine will give years and years of good service while a neglected one will cause headaches very quickly. The best example of this is to look at the cars we drive. A brand new car that is never serviced would not run smoothly for very long. Why should a different outcome be expected from equipment?