Plotter

An X-Y plotter system for forming images on a web comprising:

• first means being coupled to at least one edge of said web for imparting motion thereto to provide a first degree of motion during plotting onto said web in response to a first applied signal;
• second means for forming selected visual images on said web and being movable to provide a second degree of motion in response to a second applied signal;
• and
• third means responsive to a third applied signal for imparting motion to said second means;
• said first means including first drive means having at least one powered drive wheel contacting the web, and an idle wheel opposite to each of said drive wheels to form a pinch roller assembly with the web between the drive and the idler wheels, one of said at least one drive and idler wheels having a rough surface, and said drive and idler wheels additionally being spring biased together to cause the rough surface to make a series of indentations along the driven edge of the web to minimize slippage with these indentations repeatably mating with the rough surface of the drive wheel as the web is driven back and forth, wherein the rough surface on one of said at least one powered drive and idler wheels of the first drive means has a random pattern, size, and height of rough spots.