Support page for Dividing – Tools and Techniques

Dividing – Tools and Techniques


Welcome to the support page for my book ‘Dividing – Tools and Techniques’ by me, Alexander M du Pre and published by the Crowood Press.  The book is now on sale and available in electronic or hardback formats from or Amazon.

About the Book

I will initially approached by Crowood to write a book on dividing techniques in early 2013.  The book was commissioned in around June of that year and took around 10 months to write.  I produced all the diagrams and the vast majority of the photos myself, using real examples from my own home workshop.

The subject of the book – dividing – refers to the practice of machining equally-spaced features arranged in a circle centered on a specific point.  Examples of work requiring the application of dividing techniques include gear cutting, drilling holes on a pitch circle diameter and machining polygons, such as hexagon nuts.

The book is intended to give a thorough, practical guide to all the dividing techniques likely to be encountered in the home metalworking workshop.  It is aimed mainly at the amateur metalworker and is particularly suitable for model engineers, vehicle restorers and similar home workshop machinists.  A brief chapter-by-chapter description of the contents is as follows:

Chapter 1 Introduction to Dividing
Chapter 2 Dividing Without Special Tools Part 1. The Coordinate Method.  This method involves using the graduated handwheel dials on the milling machine to position the cutting tool accurately with respect to a datum point.  This enables features to be positioned without marking out.  It can be used for any arrangement of features including linear and circular patterns.  The method is applicable to dividing but has wider use, which is explained fully. The beauty of this method is that it can be used for some dividing operations without the need to buy additional equipment.   This chapter explains the theory and practice of using this method.
Chapter 3 Dividing with Gears.  Many dividing tools use a single gear, or a gear train, to rotate a spindle in precise increments to achieve a dividing operation.  This chapter explains how to select and set up the gears required.
Chapter 4 Dividing Plates.  Dividing plates are alternative means of rotating a spindle in precise increments.  This chapter explains how to select and set up the correct dividing plate for a dividing operation.
Chapter 5 Dividing Without Special Tools Part 2. Using the Lathe.  This chapter focuses on adapting and using the lathe itself as a dividing tool, a function which many lathes are well suited to.  As well as increasing the versatility of the lathe, this approach can avoid the need to purchase additional dividing equipment.
Chapter 6 The Dividing Head.  This chapter focuses on using the dividing head to achieve a wide range of dividing operations.
Chapter 7 The Rotary Table.  The rotary table is a versatile tool, capable of a wide range of dividing operations in addition to its wider use.  This chapter focuses on using the rotary table for dividing work, but also briefly addresses its wider use.
Chapter 8 The Spin Indexer.  This chapter describes how the spin indexer is used for dividing work.
Chapter 9 Workholding.  Workholding is a key part of any dividing operation and different methods are needed for different jobs.  This chapter gives a comprehensive description of the various methods.
Chapter 10 Electronic Dividing Methods.  This chapter gives a detailed description of the use of digital read outs for dividing work and introduces computer-controlled dividing devices.

Index.  A comprehensive index is included.


I have produced the following Excel spreadsheets to support the book.  Although these are not essential to apply the principles described in the book, they can certainly save a great deal of time.  You can download them from this website, free of charge.  Please click on the links below or go to the ‘resources’ tab at the top of the page and scroll down to find them.  Right-click the links to save to your computer.  Please note the disclaimer on the resources page.

Holes on a PCD – Coordinates Calculator

This is an Excel spreadsheet that will calculate the coordinates of any number of equally-spaced holes arranged on a PCD (Pitch Circle Diameter).  Coordinates are calculated with reference to the centre of the PCD or any other reference point.  This tool is useful for dividing operations using the coordinate method.

Right click to download Holes_on_PCD_Coords_Calculator

Dividing Plate Calculator

This Excel spreadsheet enables you to quickly generate a table of the divisions possible with your dividing plates and the worm drive ratio on your dividing head or rotary table.

Right click to download Dividing_Plate_Calculator

Geartrain Dividing Calculator

This Excel spreadsheet enables you to quickly establish a three-gear geartrain combination to achieve a set number of divisions on a dividing head.

Right click to download Gearchain_Calculator

Buy the Book

Available from the publisher, Crowood, at a discounted price of £11.99 at this link:

or from Amazon at: