CNC Turning: tool and insert selection

CNC – Tool and insert selection for Turning


How do you select the tool holder style, insert clamping type, insert clearance angle, insert shape and a dozen more parameters, so that you can cut your part in minimal time and get it to pass inspection ?

On most shop floors the tool used is a single ‘favourite’ tool, with no scientific basis for selecting the holder and insert. Just understanding the science behind the selection can improve your machining productivity hugely.

This document on selecting a tool holder and insert for CNC turning shows you the step by step process and explains the simple logic behind turning tool selection. Sorry, it’s 6 pages long, but on the bright side, it’s mostly pictures and the text is cumulatively only slightly more than a page

If some of the terms in the document are unfamiliar to you, just read these earlier posts:

Text and pics. source: CADEM NCyclopedia multimedia CNC training software.

The globalization of food – a foodie traveller’s lament

If you’re a foodie (like me), one thing you really look forward to when you travel is eating the local food. India is a foodie’s paradise, with possibly more than 200 different styles of cuisine. Whenever I travelled, I used to look forward to eating in a particular local restaurant, and the rest of the family used to give me a list of things (eatable, all of them) to carry back. Please note the past tense.


Paradise biryani in Bangalore

Distant relative of vada pav in Bangalore

Going to Hyderabad meant at least one meal of biryani at Paradise, and getting back Karachi Bakery biscuits. Pune meant eating Parsi food in Dorabjee, and getting back Chitale Bandhu Bakarwadi. Mumbai meant vada pav at a roadside cart. Lucknow meant Tunday Kababi and pickles from Chowk. Delhi meant eating at Karim’s, Rajma, Chole, Makke ki Roti and Sarson ka Saag in winter, and carrying back Rewadi and Gajak.

Globalization of food is however killing this source of joy. Bangalore has three branches of Paradise Biryani and two of Tunday kababi. I want Bilaspur food in Bilaspur, and all I see is Idli Dosa on the roadside. I even saw a van saying ‘Indore South Indian’ – this guy in Bilaspur (in Chattisgarh) is selling an Indore (in MP) variant of ‘South Indian’. In Bangalore’s ‘North Indian’ restaurants you get ghastly distant cousins of rajma, chole, and makke ki roti+sarson ka saag. One of these days there’ll be a couple of more nails in the coffin of my joy, in the form of Karim’s and Dorabjee starting branches in Bangalore.

Idli-Dosa in Simga, Chattisgarh

Indore South Indian (???) in Bilaspur, Chattisgarh

Chitale Bandhu Bakarwadi, Karachi Bakery biscuits, rewadi and gajak are all available in stores less than a km. from my home. Now my family buys this stuff in the local shops, and my importance as a source of these goodies has diminished to zero

Chitale Bandhu bakarwadi, Pune

If I suddenly make a massive amount of money (not happening in this life – maybe the next one?) I’m going to try my best to get into politics, become the Prime Minister, and outlaw this globalization of food .

Paradise biryani in Bangalore