Why, When and How to Replace Lathe Oils, Lubricants and Coolants

The squeaky wheel gets the grease is a common saying that should never apply to your lathe and its lubricants. The slides, apron, chucks, mandrels, bearings and spindles should never get to that point. Any machine shop’s pre-operation checklist should include evaluations of all the fluids and lubrication levels to avoid catastrophic failure. New LeBlond lathes make it easy to identify the fluid levels and top off the lathe lubrication reservoirs to keep everything running smoothly.

It may seem obvious why you should replace the lubrication fluids regularly, but different lubrication and cooling oils have specific purposes and benefits. The best oil or lubricant can depend on the machine component, material cut, or tool used. The lubrication used to maintain smooth operation of the machine is different than the coolants used to cut billets. Metal cutting fluids help minimize heat transfer and fluctuation, reduce friction, and manage chips that may otherwise do damage.

There are three main types of machine-cutting fluids:

1. Soluble Oils–These oils are emulsified and mixed with water. These water-soluble lubricants are prone to grow fungus and bacteria if the pumps aren’t maintained. This is the least expensive and most used type of cutting fluid.
2. Synthetic fluids–These fluids replicate natural oil lubrication but are made of polymers and chemicals. They prevent corrosion, are the cleanest and offer best cooling of the different lubricants. However, they are the least lubricant.
3. Semisynthetic fluids–use a combination of both soluble and synthetic fluids. The heat transfer performance is somewhere between soluble and synthetic fluids. These lubricants have a broad range of applications.
   One thing universal for lathe lubrication is to select a non-detergent oil. Oils with detergent attract and collect particles and chips as the metal is machined.

So, how do you know when to replace the lubricants? Depending on the lathe, you may need to either manually lubricate or this function can be automatic:

LeBlond Precision High-Speed Lathes (RKL-1300, 1500, 1700 and 1900) as well as Precision High-Speed Heavy-Duty Lathes (RKL-1600, 1800 and 2000) have a manual, one-shot handpump on the apron. It’s recommended that an operator use the manual lubrication three times per day during normal operation. Additionally, the cross slide is lubricated by oil fittings, which are lubricated by an oil can. LeBlond recommends 2-3 drops of oil to each fitting daily or as needed.

LeBlond Heavy Duty Lathes (RKL-2100, 2500 and 2900) have an auto lubrication system. It is recommended to keep the lubrication setting for the cross slide and longitude apron at 1/8” to avoid flooding the whole system, lose oil too quickly and refill lubricant more than needed. By keeping the setting at 1/8”, the lathe will typically have enough oil for an 8-hour shift. Of course, this depends on all variables: lathe speed, metal type and particular operations. At the beginning of every shift, it is important to check the head stock, apron and bedway lubrication levels are full. Whenever the carriage kicks into gear, the built-in self-lubricating pump activates. This lubrication pump can be turned off for specific operations (like cutting titanium, cast iron or other hardened steel alloys), but it is recommended to keep the pump on and set to 1/8” to maintain a sufficient flow of lubricants.

When was the last time you leveled your lathe?

If you haven’t leveled your lathe in the last 6 months, then your machine is probably due for a checkup. There are many ways a lathe can become unleveled. Common reasons for re- leveling your lathe include:

• Forklifts bumping the lathe
• Misuse or mishaps. An incident that can wreck the tooling can also put the lathe out of level
• Environmental changes. Even a change in the ambient temperature of the shop can throw off the level

Why is it important to perfectly level your lathe?

By getting the lathe level, you are assuring the most optimal performance of the lathe. There will be less scrap and waste. This is especially important when you are turning expensive metal or complicated parts. The life of the tooling can be extended since there is not any uneven pressure applied to the wrong part of the inserts. Mandrels can get bent if the level is off. Any minor offset can cause a twist in the bed and the tailstock can get out of alignment. Any misalignment can create unwanted tapering of a part. If you are machining to tight tolerances, you will want to make sure the level is as perfect as it can be for both the X-axis and Z-axis.

Leveling best practices

Before levelling your lathe, you’ll need a precision level that has been well-calibrated. Two levels are recommended, but not necessary.

For some of the larger lathes, you need to start with the inside legs to assure the bed is precisely leveled. The outer legs that provide support and stabilization for the machine get checked after inner legs are set. Clean debris from the bed and the precision leveling tool to avoid any distortion of the level. Even as much as a hair can cause the level to be off. Check the level in both the X-axis and Z-axis. Be sure to handle your level from the sides as temperature differences in the level can cause temporary distortion, giving an inaccurate reading. When in doubt, allow the level some time to reach an even temperature.

When QA checks show parts are getting out of control, it is important to perform a level check. Re-leveling your lathe will save time, avoid scrap and prevent premature wear to the machine. Taking the time to make sure the level on your lathe is as close to perfect as possible will keep your machine shop running smoothly.