Lecture By: Muftooh Ur Rehman Siddiqi ME-418 CAD/CAM Lecture #: 17 Position Control System of NC Ref: Groover (Chap – 06) Faculty of Mechanical Engineering Ghulam Ishaq Khan Institute of Engineering Sciences & Technology, Pakistan. Lecture By: Muftooh Ur Rehman Siddiqi Research Associate Office # G-17 Email: [email protected]
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Lecture 17 position systems of nc [compatibility mode]
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Lecture By: Muftooh Ur Rehman Siddiqi
ME-418 CAD/CAM
Lecture #: 17
Position Control System of NC
Ref: Groover (Chap – 06)
Faculty of Mechanical Engineering
Ghulam Ishaq Khan Institute of Engineering Sciences & Technology, Pakistan.
Lecture By: Muftooh Ur Rehman SiddiqiResearch Associate
• The NC positioning system converts the coordinates axis valuesin the NC part program into relative positions of the tool andworkpart during processing.
• The worktable moves linearly by means of a rotating leadscrewwhich is driven by a stepping motor or servomotor.
• The leadscrew has a certain pitch p (in/thread, mm/thread).The table moves a distance of p at every rotation of the lead
Uses a feedback measurements to confirm that the finalposition of the worktable is the location specified in theprogram
Normally specified for machines that perform continuouspath operations such as milling or turning, in which thereare significant forces resisting the forward motion of the
are significant forces resisting the forward motion of thecutting tool.
Closed Loop Control Closed Loop Control –– Optical EncoderOptical EncoderFrequency of the pulse is computed to determine the position and velocity of worktable.