The Mechanism and Kinematics of a Pantograph Milling Machine

Table of Contents

The Mechanism and Kinematics of a Pantograph Milling Machine

ABSTRACT

The paper is paying attention on a 2-Revolute and 1-Prizmatic (RRP) kind of manipulator kinematically. The manipulator is based on a parallelogram linkage mechanism and translates along horizontal directions and z-axis motion i.e. vertical movement is provided by effective stylus length. At the end-effecter a palm router installed with milling cutter is mounted. Compared to conventional milling machine it can traverse the de-scaled profile traversed by stylus. The forward kinematic equations have been formulated. The simulation results by solid works software approximately matches the computation formulation derived in this paper. A prototype is made-up to perform milling operation on any contour. Pantograph Milling Machine is well explained below

INTRODUCTION

Traditional milling machine were able to mill only on a plain surface or we can say only along the straight paths and could not generate the replica of already existing object. This kind of manipulator has large workspace, high sleight and good maneuverability; it can be widely used in field of painting, welding, assembly and wood/metal engraving. However due to its cantilever type structure, the manipulator is inherently not very rigid and thus the link connecting the assembly to the bed is the most vulnerable to failure due to bending load. It is poor in dynamic performance in high speed and heavy duty operations. Hence suitable for light duty and slow speed operations

Since the parallel mechanism was first invented in 1960’s and nowadays it is being used in many industrial applications. Light Rail vehicles (LRVs) are equipped with one pantograph that collects current from the contact wire. When the LRVs operate, the pantograph pan-head is in contact with the wire, and electricity is transferred to the vehicle

The mechanical efficiency of pantograph mechanisms and conventional open-chain and closed-chain type manipulators are studied and evaluated using the concept of modified geometric work. The kinematics of 6-DOF, pantograph type manipulators are studied and special: mechanisms which simplify the kinematics are introduced.

The computational complexity of both Cartesian and cylindrical type pantograph manipulators are evaluated and compared with a PUMA type manipulator

The Mechanism and Kinematics of a Pantograph Milling Machine

The pantograph mechanism is used to design and fabricate a milling machine which could traverse on any contour provided that stylus is moved along the same on any already existing object. Using such kind of manipulator we can generate the de-scaled replica of the object or we can say it to be a copying machine which can be employed in mass production with economical production/machining cost. The 3-DOF in this manipulator adds a feature to increase or decrease the depth of engrave and thus can be used in metal engraving industries or wood carving industries to copy the engraved wooden design. At the end-effecter we can replace the cutter by a welding torch or a paint brush to

perform the desired typical operation with very ease and accuracy. The only constraints are its poor dynamic performance but our kinematic analysis shows it to be perfect for light and slow speed operation.

Authors:

Mahendra Verma, Abrar Ahmad, Niyazul S Haque, Sahil L Mallick, Ishank Mehta, R. K. Tyagi