Days of Milling Past

It is interesting to see how the machine tool market has evolved in the last few decades. When I started buying CNC mills in the mid 1990s there were more builders in the market and the price disparity between commodity machines and high-end machines was much smaller. There were more mid-range machines available that offered a good balance of price, performance and tech features.

Small shops were being forced to adopt CNC milling to remain competitive. Adopting CNC milling technology allowed small shops to automate the milling process in the same way and for the same reasons that large manufacturers had adopted it. Not surprisingly, many small shops gravitated toward the commodity milling machines because they provided an economical way to automate their machining and stay competitive.

At that time the goal was to have a machine that could perform repetitive motions, create multiple pieces of geometry in one hold and allow the skilled machinist to monitor and adjust rather than turn handles. Commodity machines provided the vehicles for this transformation.

A new day

The landscape is different today. In the past, I was a proponent of small shops purchasing commodity machines, and I even wrote articles discussing how a small shop could be efficient with them. Unfortunately, it is difficult to see how most small shops can continue to be successful with commodity mills.

Process capability, or more accurately, the need for process capability is going to drive shops to move away from commodity machines.

Six sigma is the name given to the science and mathematics of process capability that everyone has heard about. While the tools can be complex, the goal is simple: Create machining processes that are accurate, precise and reliable so that the finished product is made to the desired specifications with as little intervention as possible.

Small shops were never under the same pressures that necessitated process capability for large manufacturers and, therefore, it was of little concern. Again, things are different today. While small shops will not need to employ the complex statistical tools associated with six sigma, they will need to adopt the concepts to be successful in the future

Those entering the workforce today rely unconditionally on digital technology, in every part of life. Although it seems there is a robust DIY community out there, few DIYers are familiar with the tactile nature of making things. Skilled machinists in the past were accustomed to the feel of a machine’s handles, and relied on their senses to understand what was happening with their machines and cutting tools. Digital technology is quickly eliminating the tactile experience from machining so younger machinists are not as adept at interpreting machine performance by sight, sound and smell.

Sight, sound and feel

In the past, when a new machining process was introduced, it was expected that the machinist and engineers would fine-tune it by speeding it up, slowing it down or changing to a different tool. Newer machinists may not have the opportunity to learn by sight, sound and feel like their predecessors, so machining centers and machining processes must be more stable and accurate out-of-the-box.