Milling machines  - Dividing head - Direct Indexing
 
  • Simplest form of indexing
  • Performed by disengaging worm shaft from worm wheel by means of eccentric device in dividing head
  • Spring-loaded tongue lock engages numbered slots in index plate
  • Used for quick indexing of workpiece when cutting flutes, hexagons, squares, etc.
Direct indexing divisions

Direct indexing plate usually contains three sets of hole circles or slots: 24, 30, and 36Di - Number of divisions possible to index limited to numbers that are factors of 24, 30, 36


 
Example of direct indexing
What direct indexing is necessary to mill eight slots on a circular blank?
 

Since the 24-hole circle is the only one divisible by 8 (the required number of divisions), it is the only circle that can be used in this case.

 

NB: Never count the hole or slot in which the index pin is engaged.