Machine Shop : Making a Layout
Planning before beginning any layout is one of the most important steps. Each job may require different layout tools depending on the accuracy needed; however, there are certain procedures which should be followed in any layout.
Study the shop drawing or blueprint carefully before you cut off the stock. Allow enough material to square the ends if required.
Remove all oil and grease from the work surface and apply layout dye.
Locate and scribe a reference or base line. All the other measurements should be made from this. If the workpiece already has one true edge, it can be used in place of the reference line.
Using the base line as a reference line, locate and scribe all center lines for each circle, radius, or arc.
Mark the points where the center lines intersect using a sharp prick punch.
Scribe all circles, radii, and arcs using the divider or trammel.
Using the correct type protractor, locate and scribe all straight and angular lines.
Scribe all lines for internal openings.
All layout lines should be clean, sharp, and fine. Reapply layout dye to all messy, wide, or incorrect lines and rescribe.