A pantograph is a mechanical linkage connected in a manner based on parallelograms so that the movement of one pen, in tracing an image, produces identical movements in a second pen. If a line drawing is traced by the first point, an identical, enlarged, using the same principle, different kinds of pantographs are used for other forms of duplication in areas such as sculpture, minting, engraving and milling. Because of the shape of the device, a pantograph also refers to a kind of structure that can compress or extend like an accordion. This can be found in extension arms for wall-mounted mirrors, temporary fences, scissor lifts, the first pantograph was constructed in 1603 by Christoph Scheiner, who used the device to copy and scale diagrams, but he wrote about the invention over 27 years later, in Pantographice. One arm of the pantograph contained a pointer, while the other held a drawing implement, and by moving the pointer over a diagram. By changing the positions of the arms in the linkage between the arm and drawing arm, the scale of the image produced can be changed. In 1821, Professor William Wallace invented the eidograph to improve upon the practical utility of the pantograph, the eidograph relocates the fixed point to the center of the parallelogram and uses a narrow parallelogram to provide improved mechanical advantages. The original use of the pantograph was for copying and scaling line drawings, modern versions are sold as toys. By adjusting the needles different enlargement or reduction ratios can be achieved, chevertons machine was fitted with a rotating cutting bit to carve reduced versions of well-known sculptures. Of course a three-dimensional pantograph can also be used to enlarge sculpture by interchanging the position of the model, another version is still very much in use to reduce the size of large relief designs for coins down to the required size of the coin. One advantage of phonograph and gramophone discs over cylinders in the 1890s—before electronic amplification was available—was that large numbers of discs could be stamped quickly and cheaply, when molding improved somewhat, molded cylinders were used as pantograph masters. This was employed by Edison and Columbia in 1898, and was used until about January 1902, some companies like the United States Phonograph Co. of Newark, New Jersey, supplied cylinder masters for smaller companies so that they could duplicate them, sometimes pantographically. Pantographs could turn out about 30 records per day and produce up to about 150 records per master, in theory, pantograph masters could be used for 200 or 300 duplicates if the master and the duplicate were running in reverse and the record would be duplicated in reverse. This, in theory, could extend the usability of a master by using the unworn/lesser worn part of the recording for duplication. Pathé employed this system with mastering their vertically-cut records until 1923 and this was done as the resulting cylinder was considerably loud and of very high fidelity. This system resulted in some fidelity reduction and rumble, but relatively high quality sound, Edison Diamond Disc Records were made by recording directly onto the wax master disc. If the milling head was mounted on a pantograph, a part could be cut simply by tracing a template. This was essentially the same concept as reproducing documents with a pen-equipped pantograph, Pantograph routing, which is conceptually identical to pantograph milling, also exists
Pantograph 3d rendering
A small pantograph milling machine.
Detail of the table of a larger pantograph milling machine.