Preventive maintenance an important part of a shop’s routine

Despite a shop’s best efforts, machine tools and other shop equipment break sometimes. But preventive maintenance (PM) can drastically reduce the frequency and the extent of the damage. Most machine tool builders and other equipment providers will provide the necessary maintenance steps to keep equipment up and running, but how those steps are taken is up to each shop.

An Inside Job

Component manufacturer Sterling Instrument handles virtually all maintenance matters internally, from PM on its machine tools to plumbing, HVAC and groundskeeping work at its New Hyde Park, N.Y., facility.

“I came from a bigger facility where there was no maintenance program, and machines would power down or jam up because nobody would do even simple things, such as checking the way lube,” said Shop Foreman John Lowe. “Production would slow down because of improper maintenance, and that’s something that’s easily avoidable. I guess our program was kind of born of frustration.”

Sterling’s program uses physical logs on the side of each machine, based on OEM maintenance requirements. The shop monitors coolant level and viscosity and oil levels in all areas of the machine once a week, cleans the coolant tank and changes filters yearly and checks and addresses everything on an as-needed basis every morning during machine warm up. The system has effectively eliminated any machine downtime caused by poor maintenance, according to Lowe.

North Canton, Ohio-based machine shop Stark Industrial LLC also opts to manage nearly all maintenance in-house.

“From a manufacturing standpoint, basically, none of our maintenance is outsourced,” said Manufacturing Engineer Jonathan Wilkof. “We outsource maintenance on our overhead doors, have service contracts for heating and air conditioning, have a service that calibrates our granite plates and contract out some of the more technical machine repairs, but, other than that, we have a system to take care of most maintenance ourselves.”

At one time, Stark shut down during the last week of the year to break down all the machines and see what work needed to be done. Stark still dedicates the last week of the year to maintenance, but it also established regular maintenance schedules for each CNC and manual machine, according to Wilkof.

“We found that, to meet customer deliveries and requirements, we need to have everything available at all times,” he explained, “so we have individual booklets at each machine that detail what maintenance should be done and on what schedule, be it weekly, monthly, annually or however it works out. We also include supporting information—either from the machine manual or from other sources—that the person doing the maintenance may need to refer to, so everything is available at the point of service.”

Liquid Controls, Lake Bluff, Ill., relies on its facilities manager and his staff to handle all PM, according to Manufacturing Engineer Mike Deren, and between fastidious attention to detail and close coordination with the production staff, the manufacturer of liquid measurement meters and accessories rarely runs into a problem it can’t fix.

“Even though we sometimes find ourselves pushing the machines to make production quotas,” Deren said, “we don’t run into too many problems we can’t handle ourselves.”

Courtesy of Sterling Instrument

In addition to regular maintenance on the machines themselves, Sterling Instrument keeps its shop as clean and free from clutter as possible.

Replacing worn components like bearings and electrical items is a regular occurrence, especially on older machines, he explained, and is handled in-house as issues arise.

Liquid Controls’ maintenance program typically involves shutting down one machine at a time for a routine overhaul on an annual basis. Regularly scheduled service allows production schedules to be adjusted accordingly, and, when one machine is down, the operators are free to assist in other shop operations.

“I’ve worked in shops where there was no PM,” Deren said. “When the machine broke down, that’s when it got serviced. That’s just not a good way to run things. A lot of our machines are close to 20 years old, and some of them run better than some newer machines I’ve seen in other shops, because we try to stick to that strict maintenance schedule.”

Contract Work

While in-house maintenance has its advantages, even its proponents admit there are drawbacks. Any issues outside the scope of what the shop is equipped to handle can be costly and time-consuming in the absence of established service contracts. Furthermore, small shops may not be able to realize the advantages of a full-time maintenance staff.

Rather than diverting internal resources to maintenance, PTooling, a shop with seven machine tools in Amherstburg, Ontario, trains its operators to handle routine maintenance like checking sump screens and changing air filters, but opts to invest in service contracts for the more-involved maintenance procedures.

“There just isn’t enough work to have a guy taking care of maintenance full-time,” said Marv Fiebig, company president. “Instead, we handle the routine maintenance and have the manufacturers train us on the monthly maintenance, but we contract out the big overhauls, anything beyond the scope of normal, routine stuff, to professionals.”

Typically, he continued, the outsourced operations involve complex activities such as turret and spindle alignment on machine tools, blade deviation adjustment and guide service on saws and government-mandated safety testing on lifting devices.

While the primary goal of any maintenance program is to keep machines running properly, PTooling’s maintenance regimen was developed with the additional goal of attaining ISO 9001 and API Q1 registrations, the requirements for which include formal, documented, systematic maintenance.

“It just made sense to structure it this way,” Fiebig explained. “I knew that, for example, come spring, I’d be calling to get our forklifts serviced, and in the fall we’d need to have the compressor serviced for winter, so we established a regular maintenance calendar. Now, training for routine maintenance has actually become part of our larger training matrix, making sure our guys know how to do things properly in between the big service calls.

“For us, maintenance is a critical function,” he continued. “We want to deliver quality products to our customers. We understand that having machines go down or produce substandard parts will put us out of business, so we depend on our machinery. It adds value, because our machines perform at such high levels. It’s costly and we end up beholden to someone else’s schedule to an extent, but I look at it as a small price to pay for the results.”

Keith Jennings, president and general manager of contract manufacturer Crow Corp., Tomball, Texas, said his shop also uses a hybrid approach to maintenance. In addition to a full-time, two-person maintenance staff, Crow purchases maintenance contracts for newer equipment.

“It’s something we view as a necessity,” Jennings said, “because it gets you access to that machine tool company. We spend a sizable amount on maintenance contracts, but they not only cover major issues above and beyond the scope of what my guys would normally handle, we also sometimes get parts at a discount, as well as other perks, depending on the manufacturer.”

Because a machine breakdown can cost tens of thousands of dollars, Jennings estimates that investing about $200,000 per year in PM saves his company two to three times that amount by reducing the risk of breakdowns.

A Routine Matter

Whether maintenance is handled in-house or outsourced via service contracts, some sort of regular, documented maintenance regimen plan is key to maintaining efficiency.