Advanced Precision Machining

Machine Tool Optimization; Best Maintenance Practices for Your Spindles

[May 9, 2020] As we speak, the COVID-19 domino effect is in full progress as manufacturers throughout the U.S. and the world work tirelessly to make the best out of the unfortunate business situation the recent pandemic has created. Advanced Precision Machining’s Colorado machine shop, and facilities around the country, are all up against similar challenges; economic uncertainty, supply chain disruptions, operational slowdowns, and financial losses to name but a few. All of this comes at a time when our number one priority is keeping our employees and communities we do business in safe and healthy. In our line of work, there is no working from home. With the ongoing emphasis on self-quarantining, social distancing, and avoiding groups, the obstacles manufacturers are facing during this crisis are indeed daunting. To no one’s surprise, the latest April 2020 Manufacturing ISM® Report On Business®, revealed a contraction of economic activity in the manufacturing sector, and a sharp reduction in factory production, demand and employment numbers. This will be the new, unfortunate reality in the short term.

But, there is good news to share. Many manufacturers are mounting a Coronavirus defense by transitioning their production to meet medical supply demand. Being the innovators we are, everyone is becoming involved in outside-the-box thinking with regards to keeping employees safe, healthy, and productive. States are cautiously beginning to reopen, and markets will eventually settle into a new, post-pandemic normal with more reliance on reshoring, nearshoring, and in-house activity to rebuild our supply chains. And with today’s technology, our particular precision machining industry is better equipped than ever to solve the dilemmas COVID-19 is causing around the globe. The downtime many of us are experiencing is also presenting machine shops with an unforeseen benefit. Now is the perfect time for owners and CNC machinists to take advantage of the lull in business to optimize assets and ensure machine tools are in peak condition and ready to ramp up quickly when the recovery begins.

Even in times of crisis or economic uncertainty, CNC machining facilities must still rely on a variety of best management practices to take advantage of what they have, in this case, time, and making improvements to their operation that will eventually boost their bottom line. Without sacrificing quality, service and safety, cost cutting in a machine shop environment is always at the top of the list for owners. The high-speed CNC milling and machining equipment all of us rely on is the heartbeat of any shop floor, and is likely its biggest capital investment. Proper care and maintenance are thus critical to reducing costly downtime, repair bills, and replacement while maintaining throughput and efficiency. Take your spindles for example, they can be thought of as the lifeblood of your facility, and no one wants to see future production negatively impacted due to poor maintenance practices. Upkeep is perhaps the most critical component in keeping costs down while running an efficient and money making CNC machine center. So, what better time is there to keep employees engaged and working productively than right now? Here are a few of our favorite tips to cut down on the number of repairs you may encounter when ramping up again:

Lubrication

A critical care function you can perform. Maintain lubricants at the OEM recommended levels, keep clean (check for discoloration), and replace according to the suggested maintenance schedule. Daily inspection of oil levels in all operating tanks including; gear boxes, spindle chillers, hydraulic units and central tanks must be adhered to, in addition to ensuring that all spindle bearings are properly lubricated.

Cooling System

Before powering on any CNC machine, make sure that coolant levels are correct and that strainers are clear of any debris. If so equipped, chiller systems are designed to warn you of a spindle problem; therefore it is critical to ensure that they are running properly. In addition, be certain that your coolant is aimed correctly and not splashing directly on top of the spindle. This can result in damage.

Vibration Levels

If you notice increased vibration or unusual noise, the spindle bearings have become worn out and need replacing (use OEM technicians and/or parts). Keep an eye out, and an ear out, for any triggered alarms on your milling and machining equipment.

Spindle Spring Force

The pull force of the spindle spring is critical to proper CNC machining; it secures the tool holder in the spindle. If this force becomes too weak, excess vibration, runout, and damage to the spindle and machined parts could result. Check the spring force regularly using a "draw bar pull force test". It is also good practice to perform routine runout tests using an OEM recommended spindle test bar.

Avoid Accumulating Chips

When running any CNC milling machine, avoid any accumulation of chips near the end of the spindle. These have a tendency to work their way inside the bearings, limiting their lifetime, resulting in potential damage to the spindle.

To sum up, it’s easy to overlook simple but critical issues on your CNC milling and machining equipment.  if you're not producing accurate and quality machined parts, if you notice a rise in operating temperatures, vibration levels, or unusual noise, then you have spindle problems. With proper care and regular maintenance, including investment in quality spindles to begin with, you can significantly reduce costly downtime, errors, and repairs. So, why not take advantage of today’s unforeseen slowdown in operations and take care of your most significant investment? At the same time, your machinists will be taking a proactive role in ensuring your shop will be up to the task and have peace of mind when demand inevitably ramps up again. It is our hope that all of us come out on the back end of this stronger than when we went in. And of course, APM wishes all you continued good health and safety as we get back to business.

Want to learn more about spindle maintenance, machine shop efficiency and productivity, or have a question about your next milling and machining project? Contact the expert CNC machinists at Advanced Precision Machining today. 

For more APM machine shop information; Like us on Facebook, follow us on Twitter @APMLongmont, or connect with us on LinkedIn.

About the Author

Gerry Dillon is a co-founder, current owner and certified CNC machinist at Advanced Precision Machining (APM), a full-service machine shop located in Longmont, Colorado. Before making his home in the United States in 2000, Gerry was born and raised on the emerald isle of Ireland and took an interest in milling and machining from an early age, ranking #1 in the Irish National Apprenticeship Program. In 2005, he and a partner began what’s grown into a leading Colorado machine shop. Gerry brings over 30 years of machining experience to the shop floor, and is certified in all aspects of geometric dimensioning and tolerancing.  

Copyright © 2020 Advanced Precision Machining, LLC