21-06-2011, 02:45 PM
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ABSTRACT
Indexing head mechanism generally used in milling machines is controlled manually now days. In this process various indexing methods like simple indexing, compound indexing etc are applied in the calculation. Calculation gives the rotation of indexing crank and desired number of holes in the indexing plate. But these methods are time consuming and require skilled labour because this requires changes in setting of indexing plate with some fixed time interval during operation. So for compensating this several automation methods like NC, CNC, DNC etc. are developed now a day. These methods consume less time and not require skilled and continuous labour. In our project we use NC method for controlling of indexing head mechanism. Numerical control is defined as the form of programmable automation, in which the process is controlled by the number, letters, and symbols. In other words, the numerical control is defined as the machine that is controlled by the set of instructions called as the program. So in our project we take one example of indexing and make one program using mat lab by inserting mathematical calculations in program that we have done manually in our example.
1. INTRODUCTION:
In older days for making gears, cutting splines on shafts, fluting drills, taps and reamers manufacturers use simple and manual indexing method or hand operated indexing method consist by milling machines which are very time consuming operations. So that automation of the indexing came into picture. Now a day’s manufacturer uses NC, CNC and DNC machines which are the next generation machines after the manual or automatic lathes, milling, drilling, shaping etc. machines. NC (numerical control) has been developed out of the need for higher productivity, lower cost and more precise manufacturing. This is the latest machine tool control system since the industrial revolution and can be considered as the more sophisticated form of automation for controlling machine tools, equipment or processes.
1.1 WHAT IS NC?
Numerical control, popularly known as the NC is very commonly used in the machine tools. Numerical control is defined as the form of programmable automation, in which the process is controlled by the number, letters, and symbols. In case of the machine tools this programmable automation is used for the operation of the machines. In other words, the numerical control machine is defined as the machined that is controlled by the set of instructions called as the program. In numerical control method the numbers form the basic program instructions for different types of jobs; hence the name numerical control is given to this type of programming. When the type of job changes, the program instructions of the job also change. It is easier to write the new instructions for each job; hence NC provides lots of flexibility in its use. The NC technology can be applied to wide variety of operations like drafting, assembly, inspection, sheet metal working, etc. But it is more prominently used for various metal machining processes like turning, drilling, milling, shaping etc. Due to becoming quite NC all the machining operations can be performed at the fast rate resulting in bulk manufacturing cheaper.
