Ideas from India

Shape up for high production

My idea is to use a shaper for high production by turning the machine’s idle stroke during its return motion into a cutting stroke. Doing so reduces workpiece machining by half.

I accomplish return-stroke machining by adding a clapper box with a tool, such that the toolholder arrangement has one tool clamped on the clapper box individually. The return stroke now becomes a rough-cutting one as compared with the forward one. Pneumatic power, with control accessories, drives the machine’s ram or cylinder piston for forward and return strokes.

L.M. Lakshmanan,
Coimbatore, South India

A roundabout path to better milling

On horizontal milling machines, it’s not always possible to use a cutter big enough to span the width of a flat part surface due to part size or fixture interference. However, when a smaller cutter is used to mill flats, the cutter can produce unwanted steps when it changes feed directions. The problem is further magnified when the cutter’s milling inserts wear.

To remedy this problem, move the cutter in a spiral (interpolation) path, instead of a simple X and Y-axis one. In milling cylinder blocks at our plant, the spiralpath method increased cutter life from about 40 parts to 150 before steps that were beyond an acceptable limit (30/35 percent of flatness value) began to form.

Surendra Datar,
Tata Motors Ltd.
Pune, India

A new angle on roughing

For rough cutting end faces on cylinder crank shafts, we were using a staggered-type cutter body with standard ISO 12-mm-sq inserts. These inserts are quite expensive, so to save money, we switched to using appropriate-size worn triangle-shaped inserts. We simply regrind the worn corner radii on the triangle inserts, which has saved us from having to purchase hundreds of new square-tip inserts.

Surendra Datar,
Tata Motors Ltd.
Pune, India