01 April 2010

PLoTTer



A plotter is a computer printing device for printing vector graphics. In the past, plotters were widely used in applications such as computer-aided design, though they have generally been replaced with wide-format conventional printers, and it is now commonplace to refer to such wide-format printers as "plotters," even though they technically aren't.

Vinyl Sign Cutter

A vinyl sign cutter (sometimes known as a cutting plotter) is used by professional poster and billboard sign-making businesses to produce weather-resistant signs, posters, and billboards using self-coloured adhesive-backed vinyl film that has a removable paper backing material. The vinyl can also be applied to car bodies and windows for large, bright company advertising and to sailboat transoms. A similar process is used to cut tinted vinyl for automotive windows.

Static Cutting Table

A sign cutter typically functions like a traditional roll-fed or sheet-fed plotter, in that the media to be cut is kept rigid by a backing sheet as pieces of vinyl are cut out. As the letters are cut, the backing keeps the material properly aligned in the moving rollers. This does not work when cutting a non-rigid material with no backing, such as fabric textiles or leather. Cutting a hole or slit will cause the unsupported material to droop and fall out of alignment.
The static cutting table uses a large flat vacuum cutting table instead of a roll feed. The surface of the table has a series of small pinholes drilled in it. Material is placed on the table, and a sheet of plastic overlaid onto the fabric. A vacuum pump is turned on, and air pressure pushes down on the plastic cover sheet to hold the fabric in place. The table then operates like a normal vector plotter, using various cutting tools to cut holes or slits into the fabric. The plastic overlay is also cut, which leads to a slight loss of vacuum, but this loss is usually not significant.
This configuration allows static cutting tables to cut flexible and non-rigid materials that are difficult or impossible to cut with roll-fed plotters. Static cutters are also capable of cutting much thicker and heavier materials than a typical roll-fed or sheet-fed plotter.

• DRUM PLOTTER

A type of pen plotter that wraps the paper around a drum with a pin feed attachment. The drum turns to produce one direction of the plot, and the pens move to provide the other. The plotter was the first output device to print graphics and large engineering drawings. Using different coloured pens, it could draw in colour long before colour inkjet printers became viable. Contrast with flatbed plotter. Drum Plotter
A drum plotter is also known as Roller Plotter. It consists of a drum or roller on which a paper is placed and the drum rotates back and forth to produce the graph on the paper. It also consists of mechanical device known as Robotic Drawing Arm that holds a set of coloured ink pens or pencils. The Robotic Drawing Arm moves side to side as the paper are rolled back and forth through the roller. In this way, a perfect graph or map is created on the paper. This work is done under the control of computer. Drum Plotters are used to produce continuous output, such as plotting earthquake activity.



• FLATBED PLOTTER

A graphics plotter that contains a flat surface that the paper is placed on. The size of this surface (bed) determines the maximum size of the drawing. Contrast with drum plotter. Flatbed Plotter
A flatbed plotter is also known as Table Plotter. It plots on paper that is spread and fixed over a rectangular flatbed table. The flatbed plotter uses two robotic drawing arms, each of which holds a set of coloured ink pens or pencils. The drawing arms move over the stationary paper and draw the graph on the paper. Typically, the plot size is equal to the area of a bed. The plot size may be 20- by-50 feet. It is used in the design of cars, ships, aircrafts, buildings, highways etc. Flatbed plotter is very slow in drawing or printing graphs. The large and complicated drawing can take several hours to print. The main reason of the slow printing is due to the movement mechanical devices.
Today, mechanical plotters have been replaced by thermal, electrostatic and ink jet plotters. These systems are faster and cheaper. They also produce large size drawings.

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