MMS Blog

High-Torque Retention Knobs Solve Aerospace Milling Production Challenge

Lack of contact between a CNC machine’s spindle and toolholder, a toolholder’s lack of balance/concentricity, and improper seating within the spindle can increase cycle times and reduce material removal rates, leading to increased time for part completion.

L.H. Thomson of Macon, Georgia, progressively addressed these issues by implementing JM Performance Products’ high-torque retention knobs. By doing so, the company was able to eliminate the toolholder expansion responsible for its costly and ongoing CNC milling and boring issues.

Use Your Machinists to Make Dies

“Becoming a tool and die maker is like driving a car — you don’t start out as a racecar driver. It takes awhile to get there,” says Neil Dohe. “You have to get a feel for what you’re doing, and that only comes with years of experience.”

In making this analogy, Mr. Dohe, who is the operations and sales manager at Dies Plus, a division of Otto Engineering, does not mean to imply a hierarchy between machinists and tool and die makers. Instead, his point is that a tool and die maker usually has a very specific skillset — one that includes the experience necessary to understand the “why” behind every cut that is made and how it translates to fitting the die components together during final assembly.

Hard Milling Replaces Hand Grinding in Finishing Die Components

How far can hard milling go? Hard milling’s uses in moldmaking and other high-precision tooling work is well-documented. It skips time-consuming steps like EDM or hand polishing, saving time and money. However, a leading hard milling application is demonstrated by the die-production process at Feintool, where milling even seemingly slight details that once would have been hand-ground has proven vital for realizing repeatability in some of the most precise metalforming tooling. Feintool both manufactures and operates machines for the forming process known as fine blanking. For this company, hard milling has replaced essentially all hand-work operations, and the company is looking at replacing jig grinding as well.

One of the rarer processes that manufacturers come across, fine blanking is a precision die-cutting and shaping process for making high volumes of parts, often with complex structures. Unlike standard blanking, fine-blanking dies have rigid cutting edges with 0.5% clearance between the edge and workpiece, 10 times more precise than that of standard blanking. According to Feintool Executive VP of Sales and Marketing Lars Reich, “The precision and rigidity of the process enables fine-blanking machines to produce thousands of parts per day with excellent flatness, 90-degree edges and excellent dimensional accuracy, with most parts needing no postprocessing.”

Deciding to Specialize as an Aerospace Supplier

Indiana Precision Grinding (IPG) is no stranger to making business changes. William Cox founded the company in Indianapolis in 1975 as the Centerless Grinding Co., but when he realized the volume of local centerless grinding work wouldn’t support the business, he expanded its capabilities to include other grinding services, such as cylindrical grinding. In the mid-1980s, the company moved and rebranded as IPG to reflect these changes.

IPG is in the middle of another shift, this time from a job shop business model that serves a diverse local customer base to one that specializes in aerospace work. This was a difficult decision for IPG to make, and has required new equipment, an AS9100-certified quality management system (QMS) and a marketing plan. But the company’s president says recent changes in the manufacturing industry have made this shift necessary even in spite of recent turbulence in the aerospace sector, and it is proving successful so far.

Mapping the Optimal Path for Machinists

When shops first implement a machine monitoring system, it’s not uncommon for them to discover their machine uptime is lower than they thought. “All machine monitoring solutions out there show you how bad the production is because you collect data. You know that you’re at like, 40% uptime, but you don't know how to improve,” says Frederic Scherer, CEO of JITBase (Montreal, Quebec, Canada), a machine monitoring solutions provider. Shops are usually on their own when it comes to using this data to increase uptime. However, JITBase has devised a way to use machine data to create a clear map for shops to increase production.

Mr. Scherer says the idea for the product came from one of JITBase’s customers, an aerospace manufacturer that makes landing gear components with cycle times that range to 24 hours. “What they realized is that 80% of the time they had one machinist that is behind the machine and is just waiting for the machine to do the job,” Mr. Scherer says. “It was independent production from 80 to 90% of the time. The operator was waiting, doing nothing.” The customer asked him if JITBase could use the data it was collecting to help its machinists manage more machines. Mr. Scherer said yes, and as he thought about it, he realized this solution could help address the shortage of skilled manufacturing workers many areas are facing.