The big order is late. The chief programmer takes sick leave

The big order is late. The chief programmer takes sick leave. Your best customer just sent a text message asking for an offer that was due last Tuesday. Who has time to worry about the lubricating oil dripping slowly from the back of the CNC lathe, or wondering if the slight buzzing noise you hear from the horizontal machining center means a spindle problem?
This is understandable. Everyone is busy, but neglecting the maintenance of the machine is not like driving to work when the left rear tire pressure is a bit low. The cost of failing to maintain CNC equipment regularly and adequately is much higher than the inevitable but unexpected repair costs. This may mean that you will lose part accuracy, shorten tool life, and possibly weeks of unplanned downtime while waiting for parts from overseas.
Avoiding it all starts with one of the simplest chores imaginable: wiping the equipment at the end of each shift. This is what Kanon Shiu, a product and service engineer at Chevalier Machinery Inc. in Santa Fe Springs, California, said, he lamented that too many machine tool owners can do better on this most basic housekeeping project. “If you don’t keep the machine clean, it will almost certainly cause problems,” he said.
Like many builders, Chevalier installs flush hoses on its lathes and machining centers. These should be good for spraying compressed air on the surface of the machine, because the latter can blow small debris and fines into the channel area. If equipped with such equipment, the chip conveyor and conveyor belt should be kept open during the machining operation to avoid chip accumulation. Otherwise, the accumulated chips may cause the motor to stop and damage when restarting. The filter should be cleaned or replaced regularly, as should the oil pan and cutting fluid.

CNC-Lathe.1
“All of this has a big impact on how quickly we get the machine up and running again when it eventually needs repair,” Shiu said. “When we arrived at the site and the equipment was dirty, it took longer for us to repair it. This is because the technicians may clean the affected area in the first half of the visit before they can start diagnosing the problem. The result is no Necessary downtime, and it is likely to incur greater maintenance costs.”
Shiu also recommends using an oil skimmer to remove miscellaneous oil from the oil pan of the machine. The same is true for Brent Morgan. As an application engineer at Castrol Lubricants in Wayne, New Jersey, he agrees that skimming, regular oil tank maintenance, and regular monitoring of the pH and concentration levels of the cutting fluid will help extend the life of the coolant, as well as the life of cutting tools and even machinery.
However, Morgan also offers an automated cutting fluid maintenance method called Castrol SmartControl, which may affect the scale of any workshop that intends to invest in a centralized cooling system.
He explained that SmartControl has been launched “about a year.” It was developed in cooperation with the industrial control manufacturer Tiefenbach, and is mainly designed for stores with a central system. There are two versions. Both continuously monitor the cutting fluid, check the concentration, pH, conductivity, temperature, and flow rate, etc., and notify the user when one of them needs attention. More advanced versions can automatically adjust some of these values-if it reads a low concentration, SmartControl will add concentrate, just like it will adjust the pH by adding buffers as needed.
“Customers like these systems because there are no troubles associated with cutting fluid maintenance,” Morgan said. “You only need to check the indicator light and if there is any abnormality, please take appropriate measures. If there is an Internet connection, the user can monitor it remotely. There is also an onboard hard drive that can save 30 days of cutting fluid maintenance activity history.”
Given the trend of Industry 4.0 and Industrial Internet of Things (IIoT) technology, such remote monitoring systems are becoming more and more common. For example, Kanon Shiu of Chevalier mentioned the company’s iMCS (Intelligent Machine Communication System). Like all such systems, it collects information about various manufacturing-related activities. But equally important is its ability to detect temperature, vibration and even collisions, providing valuable information for those responsible for machine maintenance.
Guy Parenteau is also very good at remote monitoring. The engineering manager of Methods Machine Tools Inc., Sudbury, Massachusetts, pointed out that remote machine monitoring allows manufacturers and customers alike to establish operational baselines, which can then be used by artificial intelligence-based algorithms to identify electromechanical trends. Enter predictive maintenance, which is a technology that can improve OEE (overall equipment efficiency).
“More and more workshops are using productivity monitoring software to understand and optimize processing efficiency,” Parenteau said. “The next step is to analyze the component wear patterns, servo load changes, temperature rises, etc. in the machine data. When you compare these values ​​with the values ​​when the machine is new, you can predict a motor failure or let someone know that the spindle bearing is about to fall off .”
He pointed out that this analysis is two-way. With network access rights, distributors or manufacturers can monitor the customer’s CNC, just as FANUC uses its ZDT (zero downtime) system to perform remote health checks on robots. This feature can alert manufacturers to potential problems and help them identify and eliminate product defects.
Customers who are unwilling to open ports in the firewall (or pay a service fee) can choose to monitor the data themselves. Parenteau said there is no problem with this, but he added that builders are usually better able to identify maintenance and operational issues in advance. “They know the capabilities of the machine or robot. If anything goes beyond a predetermined value, they can easily trigger an alarm to indicate that a problem is imminent, or that the customer may push the machine too hard.”
Even without remote access, machine maintenance has become easier and more technical than before. Ira Busman, vice president of customer service at Okuma America Corp. in Charlotte, North Carolina, cites new cars and trucks as examples. “The vehicle’s computer will tell you everything, and in some models, it will even arrange an appointment with the dealer for you,” he said. “The machine tool industry lags behind in this regard, but rest assured, it is moving in the same direction.”
This is good news, because most people interviewed for this article agree on one thing: the shop’s job of maintaining equipment is usually not satisfactory. For Okuma machine tool owners seeking a little help in this annoying task, Busman pointed to the company’s App Store. It provides widgets for planned maintenance reminders, monitoring and control functions, alarm notifiers, etc. He said that like most machine tool manufacturers and distributors, Okuma is trying to make life on the shop floor as simple as possible. More importantly, Okuma wants to make it “as smart as possible.” As IIoT-based sensors collect information about bearings, motors, and other electromechanical components, the automotive functions described earlier are approaching reality in the manufacturing field. The machine’s computer continuously evaluates this data, using artificial intelligence to determine when something goes wrong.
However, as others have pointed out, having a baseline for comparison is essential. Busman said: “When Okuma manufactures a spindle for one of its lathes or machining centers, we collect the characteristics of vibration, temperature, and runout from the spindle. Then, the algorithm in the controller can monitor these values ​​and when it reaches a predetermined point When the time comes, the controller will notify the machine operator or send an alarm to the external system, telling them that a technician may need to be brought in.”
Mike Hampton, Okuma’s after-sales parts business development expert, said that the last possibility—an alert to an external system—is still problematic. “I estimate that only a small percentage of CNC machines are connected to the Internet,” he said. “As the industry increasingly relies on data, this will become a serious challenge.
“The introduction of 5G and other cellular technologies may improve the situation, but it is still very reluctant—mainly the IT staff of our customers—to allow remote access to their machines,” Hampton continued. “So while Okuma and other companies want to provide more proactive machine maintenance services and increase communication with customers, connectivity is still the biggest obstacle.”
Before that day arrives, the workshop can increase uptime and parts quality by arranging regular health checks of its equipment by using cue sticks or laser calibration systems. This is what Dan Skulan, general manager of industrial metrology at West Dundee Renishaw, Illinois, said. He agrees with others interviewed for this article that establishing a baseline early in the life cycle of a machine tool is a critical part of any preventive maintenance plan. Any deviation from this baseline can then be used to identify worn or damaged components and out-of-level conditions. “The first reason that machine tools lose positioning accuracy is that they are not installed safely, leveled correctly, and then checked regularly,” Skulan said. “This will make high-quality machines perform poorly. On the contrary, it will make mediocre machines behave like much more expensive machines. There is no doubt that leveling is the most cost-effective and easy to do.”
A notable example comes from a machine tool dealer in Indiana. When setting up the vertical machining center, the application engineer there noticed that it was incorrectly positioned. He called Skulan, who brought one of the company’s QC20-W ballbar systems.
“The X-axis and Y-axis deviated by about 0.004 inches (0.102 mm). A quick check with a level gauge confirmed my suspicion that the machine is not level,” Skulan said. After placing the ballbar in repeat mode, two people gradually tighten each ejector rod in turn until the machine is completely level and the positioning accuracy is within 0.0002″ (0.005 mm).
Ballbars are very suitable for detecting verticality and similar problems, but for error compensation related to the accuracy of volumetric machines, the best detection method is a laser interferometer or a multi-axis calibrator. Renishaw offers a variety of such systems, and Skulan recommends that they should be used immediately after the machine is installed, and then used regularly according to the type of processing performed.
“Suppose you are making diamond turned parts for the James Webb Space Telescope, and you need to keep tolerances within a few nanometers,” he said. “In this case, you might perform a calibration check before each cut. On the other hand, a shop that processes skateboard parts into plus or minus five pieces can live on with the least amount of money; in my opinion, this is at least Once a year, provided that the machine has been settled and maintained at a level.”
The ballbar is simple to use, and after some training, most shops can also perform laser calibration on their machines. This is especially true on new equipment, which is usually responsible for setting the internal compensation value of the CNC. For workshops with a large number of machine tools and/or multiple facilities, the software can track maintenance. In Skulan’s case, this is Renishaw Central, which collects and organizes data from the company’s CARTO laser measurement software.
For workshops that lack time, resources, or are unwilling to maintain machines, Hayden Wellman, senior vice president of Absolute Machine Tools Inc. in Lorraine, Ohio, has a team that can do so. Like many distributors, Absolute offers a range of preventive maintenance programs, from bronze to silver to gold. Absolute also provides single-point services such as pitch error compensation, servo tuning, and laser-based calibration and alignment.
“For workshops that do not have a preventive maintenance plan, we will perform daily tasks such as changing hydraulic oil, checking for air leaks, adjusting gaps, and ensuring the level of the machine,” Wellman said. “For shops that handle this on their own, we have all the lasers and other tools needed to keep their investments running as designed. Some people do it once a year, some people do it less frequently, but the important thing is that they do it often.”
Wellman shared some terrible situations, such as road damage caused by blocked oil flow restrictor, and spindle failure due to dirty fluid or worn seals. It doesn’t take much imagination to predict the end result of these maintenance failures. However, he pointed out a situation that often surprises shop owners: machine operators can compensate for poorly maintained machines and program them to solve alignment and accuracy problems. “In the end, the situation becomes so bad that the machine stops working, or worse, the operator quits, and no one can figure out how to make good parts,” Wilman said. “Either way, it will eventually bring more costs to the store than they have always made a good maintenance plan.”


Post time: Jul-22-2021

Send your message to us:

Write your message here and send it to us