Simple Indexing
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Simple indexing uses a worm gear attached to a crank to rotate a dividing head spindle in precise increments. Turning the crank one full rotation rotates the spindle 1/40th of a full turn due to the 40 tooth worm wheel. To calculate the number of crank turns needed for a given number of divisions, divide 40 by the number of divisions, with examples given of dividing 40 by 8 and 7 to get the turns required to cut 8 and 7 flutes, respectively.
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Simple Indexing
- 1. 1 Simple Indexing • Work positioned by means of crank, index plate, and sector arms • Worm attached to crank must be engaged with worm wheel on dividing head spindle • 40 teeth on worm wheel • One complete turn on index crank cause spindle and work to rotate one-fortieth of a turn (ratio of 40:1)
- 2. 2 Simple Indexing • Calculating the indexing or number of turns of crank for most divisions, simply divide 40 by number of divisions to be cut or, 40 Indexing = N
- 3. 3 Simple Indexing • The indexing required to cut eight flutes: crankindexofturnsfull5 8 40 = • The indexing required to cut seven flutes: crankindexofturns 7 5 5 7 40 = The five-sevenths turn involves use of an index plate and sector arms.