if you are using a set of purchased plans as appose to self drawn plans be aware The were more than likely printed on a Xerox process type printer. The Xerox process very slightly distorts the scale in one axis and it heats the media as it is being copied to. Seldom will you ever fine a plan set that has been printed via Xerox process that one axis or the other is not out a tad in relationship to the other axis. this is the axis that the paper ran through the machine. Just be aware and it should not be a problem for you. Most plans sets you buy will place a notice on the plans telling you this is possible.
A good thing to know when following plan prints
Truth is a plan set, or at least most are really is not intended to be used as templates. but rather to provide required dimensional data in the form of published dimensions (the dimensions shown on the plans) if you ever look at a set of drawing from a manufacturing company like General Dynamics, Weatherford, Stewart Stevens ect; Almost with out exception there will be a written notice somewhere close to title block that says "Do not scale this drawing" This notice is not there because the drawing was drawn out of scale. It is there because the copy/printing process can and will distort the image. the manufacturing company does not want their employees to try to determine a dimension by means of laying a scale on the face of the image. Rather it is the Engineering/ Drafting departments responsibility to provide all pertinent dimensions required on the face of the drawing so that a fabricator never needs to lay his or her scale on the drawing.
Trusting the printed image is some what risky unless you confirm the image to the published dimensions in both axis first. In fact if one of our fabricators or machinist are caught scaling an image on a drawing for the second time they are subject to dismissal.
just a tid bit to store in the back of the gray matter
