A dividing head for the Unimat SL.

Another usefull accessory, indexing tables or dividing heads are used when milling or drilling. They can be used when cutting gears, cutting keyways in cylindrical work or drilling holes in a circular pattern, think bicycle hub. Another use is to mill work square, rectangular etc. Wiki explains it better!

The Unimat indexing head can be used horizontaly or vertically and is designed to be mounted to the cross-slide.

A chuck (3 or 4 jaw) or surface plate bolts onto it to hold the work. To index the work there is an indexing plate inside the body, which looks like a gear wheel. A plunger locates into the slots. Different plates have different numbers of slots, mine has 48 but plates are available with 30, 36 or 40 slots. So, if I wanted to drill 4 holes in a wheel I'd count 12 slots then drill, and another 12 holes etc., 48 divided by 4 equalling 12. Swapping the plates is a simple matter of removing a circlip.

Here it is, with a 3 jaw chuck fitted, being used to mill the rectangular mounting plate of a 4mm scale buffer (click on the pic. for a bigger image);

Paul.