Materials Matchup● JUL 19, 2020 15:37:40 AM

The multiple benefits of multi-axis machining

     Modern machining technology is mind-boggling. Many machinists can remember when machining meant you controlled one axis at a time. Feeds and rapid traverse were predominately in the x-axis, while y and z were adjusted manually. If you needed more than that, you tilted  the head or used a rotary table—sometimes both. Who would have ever predicted back then that several axes could be programmed to move simultaneously via computer technology? These developments have spawned a new breed of machine shop workers. No longer does a machinist carry around trigonometry tables or work with formulas to determine feeds and speeds. All that computation is performed by powerful manufacturing software that requires a different kind of skill and training.
     Today there are 5-, 7-, and even 9-axis computer numerically controlled (CNC) machines. Of course, most CNC machining can still be done efficiently using three axes—X, Y, and Z. But the ability to complete secondary operations without removing or resetting a part is a powerful argument for multi-axis machining.

What is 5-axis CNC machining?

     Simply stated, 5-axis CNC machines have the ability to move a part or a cutting tool along five different axes simultaneously. While this is particularly advantageous in parts that require complex machining, there are other reasons for the growing popularity of these machine tools:  
1. Done-in-One Shot: Single-setup machining reduces lead times and increases efficiency.
2. Safer machining: Being able to tilt the table or the cutting tool avoids collisions with the tool holder.
3. Longer tool life: Tilting the tool and table helps maintain the best cutting position and helps maintain a constant chip load.

Why do shops spend so much on a machine tool?

     Yes, multi-axis machines are expensive. Even those in the mid-price range cost $150,000 to $200,000. And they’re not always sitting on the showroom floor waiting to be shipped. Lead times can be several months. But it’s worth the wait. Here’s why: 
- More opportunities for work: Manufacturers that are looking to outsource machining will pay particular attention to machine shops that have extensive capabilities.
- Reduced labor cost-per-part: This is good for the machine shop, manufacturer and the customer.
- Less floor space required: Instead of separate machines occupying a lot of space, you have one machine
- Faster deliveries: You can cut down the time it takes to move from machine to machine and tooling reconfiguration.
- Lower programming costs: Multi-axis means that the machinist can write several operations in one program - saving time and potential errors.

How does all of this benefit the oil and gas industry?

     Think about all of the machined parts that go into just one offshore drilling platform. Some of the parts, like this pump casting, are large, while others are tiny. There are complex parts that require more than five axes, and many that are somewhat more straightforward.  But no matter the size or complexity, all of these machined parts demand tight tolerances, consistent quality, and on-time delivery. In other words, they require the services of a machine shop with multi-axis machining capability.  Here are 2 additional benefits that I think are most important to the oil and gas industry.

1.  Working with difficult materials

     Machine shops who manufacture parts for the oil and gas industry face a host of challenges. There are parts like guide bushings, pistons and rings, high-pressure pump components, sleeve bearings, shaft sleeves, gear blanks, and valve stops.  
     These parts are made from cast aluminum alloys, stainless steels, Inconel, Hastelloy, alloy steels, iron alloys, and copper-based alloys such as copper beryllium. Pistons, made from cast aluminum, and piston rings, from cast iron, are not difficult to machine. The rings, which are subject to wear, are given a hard chromium finish to help resist it.
     Some components are machined from Inconel, and anyone who has worked with it will agree that it’s not easy to machine. The same holds true for Hastelloy. Ceramic tools are designed to remove material quickly. The key is getting the rpm’s and the feed rates set up correctly.
     Working with these alloys can be intimidating, but shops that are experienced in machining these metals have long passed the learning curve and have perfected their methods.

2.  Safeguarding people and the environment

     Most industries place a premium on conducting their businesses by placing a high value on respect and care for people and the environment. The oil and gas industry is no exception. The well-being of their employees, their contractors, and the communities in which they work is paramount.  
     Every component that goes into their drilling rigs and refineries contributes to the safety of the workers and the health of the environment. Multi-axis machines are producing many of those components. One cannot underestimate their importance.