Why maintenance should not be overlooked: CNC tips

Production stops when the CNC machine is down. When it comes to breakdowns, prevention is the goal, but repairs are a reality, too. So let's explore why proper maintenance is essential for profitability...

Regular & preventive maintenance = machine efficiency = satisfied clients

A machine breakdown can cost a lot: thousands of dollars in wasted hours, urgent shipping of replacement parts, missed customers' deliveries, not to mention a damaged reputation. 

The importance of quality toolholding

Toolholders, collets, collet nuts and torque spanners,... All play a critical part and represent a small investment that can make an enormous difference in productivity, cost saving and profit.

Toolholding, whose significance is often overlooked plays a very important, critical part in connecting the machine spindle and cutting tool. When the CNC set-up is not coupled with clean, accurate parts & accessories, it can have problematic if not disastrous results causing significant production downtime and costly rework.  

Read more about the quality toolholding HERE.

Plan how to service and maintain your CNC

Many of today’s CNC routers have achieved a high tech sophistication for workshops focused on providing precise cutting, engraving and shaping to meet their customers’ demands. Generally these machines are capable of 20 years of productivity. The more regularly a router runs, the more income the shop can generate. An idle router doesn’t make money. All too often the reason for a router’s downtime has nothing to do with the design of the machine and everything to do with how it is being maintained.

Every router comes with a recommended maintenance program, but while employees may conscientiously try to follow it, they can still sometimes fall short. Their difficulties cannot be brushed aside by simply attributing maintenance shortcomings to negligence. Usually, the smallest and seemingly most innocent oversights end up jeopardising operations over the long term, perhaps due to the rush of the production schedule or a shortage of manpower on a particular day.

Frankly, whatever the cause, the problem is the same. Everything from less-than-thorough lubrication to improper tooling in the spindle will play a role in shortening a router’s lifespan. Router downtime can certainly occur for reasons unrelated to routine maintenance, such as an electrical outage caused by extensive dust in the facility, but for the most part, such occurrences are rare.

General guidelines

Maintenance schedules tend to vary by specific machine and model, but the following five guidelines apply to all of them:

1. Ensure cleanliness
   It does not take long for CNC routers to get very dirty. Most of them operate in what can be considered a highly dusty environment, which visibly accentuates the need for cleanliness, but build ups of dust, fluids or chips can also easily get into the bearings and controls. This is a sure recipe for problems if it is not corrected every day with cleaning.
   Manufacturers generally recommend hand-sweeping of their machines. A judiciously used air gun is an effective tool for keeping substances away from the bearings. Another fairly standard recommendation is to lower the router’s air pressure during the cleaning process to reduce the risk of contaminants being 'driven in' to bearings, seals etc.. Rack systems should be kept well-lubricated to prevent machine downtime.
2. Change the filters
   Just as clogged filters jeopardise the efficiency of an automobile’s engine, so too must a CNC router’s control box and vacuum pump filters be changed on a regular basis, along with the filters that trap oil and water in the pneumatic lines.
   As a rule of thumb, all filters should be checked weekly and changed as needed, but there is no standardised schedule. Rather, the frequency of the changes will vary, depending on the specific machine, the types of materials being cut and other environmental factors in the facility, such as dust and dirt.
3. Machine Lubrication
   Despite their many parts, CNC routers do not require extensive lubrication, but breakdowns will be inevitable if the process is not followed as required. And, please note, should the failure to lubricate cause a malfunction, there is a real possibility of voiding the manufacturer’s warranty.
   Lubrication is so basic a step, no reminders should be necessary—but reminders help emphasise its importance. Bearings, pumps and oscillating knives all need regular lubrication and, again, the maintenance schedule will vary depending on the type of machine, the extent of its use and the environment around it.
4. Keep the air supply clean
   Most CNC routers operate with pneumatic air, which has to be clean, dry and maintained at a steady pressure greater than 552 kPa (80 psi). With the incorrect specifications, damage to the machine is likely in a very short time frame, so the air pressure should be checked regularly.
5. Provide safe and proper electrical power
   As with any electrical machinery, the power supply to a CNC router must be sufficient and safely connected as required under any local power regulations.
   Failure is most likely to occur in cases of poor electrical grounding, low voltage or insufficient capacity. Also, as is the case with other computer-operated mechanism, a spike in power can cause serious damage.

A detailed schedule

Each CNC router is accompanied by the manufacturer’s guide for preventive maintenance, including inspection forms, times for logging operating hours, general cleaning steps, air pressure readings and guidelines for oiling an oscillating knife for example, checking the pump oil and cleaning the cover nut threads. 

A Preventative Maintenance Plan (PMP) is vital to keeping machines running and making money. Routine check-ups boost output efficiencies, increase uptime and improve profit margins. 

Implement regular CNC maintenance checks to ensure there are no potential failures to your valuable equipment. Doing a few minor checks at the end of each day or each shift can help catch a problem before it snowballs into a major breakdown. 

We hope this is useful in helping you create a successful maintenance schedule to suit your machine. If you have any further questions on what best for your machine, you’re best to contact your machine supplier or manufacturer. For the tools to help you clean, maintain and service better, click here.

Beyond the checklist

Those who use CNC routers have also learned there are times when a checklist is not enough to ensure smooth operations. Much like a vehicle, if the router does not sound just right, then additional analysis is necessary, even in cases where all of the checklist steps have been completed in a timely fashion.

The emphasis on preventive maintenance should be the same throughout the useful life of the machine as it was at the beginning. Users will need a cleaning procedure and must make sure to remove, clean and check every tool in the spindle and toolholders.

The best way to ensure lengthy, productive CNC router operations and to reap the full benefits of the machine’s capabilities is to follow the manufacturer’s maintenance recommendations, but it may also be worthwhile to consider other service packages that are offered by the same manufacturer. This is because all machines, regardless of their sophistication and how thoroughly their maintenance plan is followed, will experience wear and tear over time and, if a machine is idled, then the workshop can be left with an expensive, non-functioning piece of equipment.

Please note the above is written simply as a suggestions list. It does not purport to be a comprehensive maintenance schedule in itself. 

DO YOU HAVE MORE QUESTIONS? 

Every day our team strives to boost your confidence, productivity and results through our accurate service and tailored support. Feel free to contact us on  0800 488 647 or sales@tungstenandtool.co.nz to find out more information on CNC routers.