February 2008 Edition

FROM THE SHOP FLOOR

Sterling's Little Helpers

Dave takes the name of the column seriously and examines the items that make life easier on the shop floor

When I wrote my first column for MAN I didn't have any grand plans, I just took three tools that I had seen at IMTS 2006 and wrote about their benefits. I've covered a multitude of topics since then and despite this column's title, some of the subjects have gotten away from the shop floor and wandered into the office. To bring the subject back to the shop floor, this column will be about tools we frequently use here at Ansco.

Welcome Back, Cermet

Years back we would use cermets for some finishing work. At the time, the technology was limited and the tools were difficult to use. Grades were generally too brittle, and chip breakers were ineffective on a lot of the steels we commonly machined. To further drive us away from cermets at the time, great strides were being made in carbide. We switched to some newer grades of carbide and didn't look back. That is until a pesky salesman saw a large "tumbleweed" of chips building up on a shaft we were machining. He suggested we try a cermet. We were hesitant. But, when we ran a test of the new grade and chip breaker, we were impressed. We were breaking chips at a depth of cut of only 0.025", and getting a great finish because we were not dragging stringy chips back over the finished surfaces. So far, the cermet grades are holding up well on many tough forged steels.

A Different Angle for Profiling

In a job shop, we never know what kind of parts are going to come through the door. Because of this, versatility is a key to success. Tungaloy has come out with a versatile tool that has helped me out of tight jams. They call it a YNMG insert, and it helped solve many machining quandaries. It's a diamond shaped insert that fits in any VNMG 35° holder. The difference is in the shape. While it may fit in a 35° socket, it has an included angle of 25°. Many of our parts have oil slinger V grooves with included angles of 30°. We recently machined an automotive pulley with an included angle of 35°. The YNMG let me machine those parts without any special tooling. The inserts come in a variety of grades and chip breakers to suit different materials. Keeping a pack around comes in handy.

Staying True to Form

In a past column I wrote about the pitfalls of machining aluminum and I recommended thread forming taps. The taps can boost thread quality and tool-life, and I still recommend them.

A challenge we encountered though, was getting the proper hole drilled in the part before forming. Since the thread-forming tap is pushing material, the typical drill size is not applicable. Unfortunately, no one thought of thread forming when they gave us the fractional, letter, and number drill sizes.

It's the small things that make life easier. The YNMG insert, with an angle of 25°, is a handy tool Dave keeps on hand at his shop.

Luckily the folks at Guhring make a variety of drill styles in a multitude of sizes. In aluminum I prefer the GT100 type. It has large parabolic flutes for excellent chip and coolant flow, and a bright finish that keeps aluminum from building up on the edge. The high speed steel material means that it is inexpensive, but its sharp, high-performance grind performs well in aluminum. For thread forming, it is available from sizes as small as 0.020" up to 0.638", with so many sizes in between it would take two pages to list them. I was able to find the exact sizes I needed for any thread-forming.

Your Mileage May Vary

You don't need to rush out and buy all of these products, but they've proven useful around the shop in the last few months. To give credit where it's due, all three of these products were brought to my attention by sales reps. Without their help I would need to spend a lot more of my time digging through catalogs and websites, and in some cases, I would have never even learned about some of the products that have proved so useful.

Dave is responsible for programming, tool selection, and fixture design for Ansco Machine's 20 CNC machines in Peninsula, OH

What do you think?
Will the information in this article increase efficiency or save time, money, or effort? Let us know by e-mail from our website at www.ModernApplicationsNews.com or e-mail the editor at pnofel@nelsonpub.com.