Figure 3-45.Principles of template layout.
Figure 3-46.Simple miter turn.
degrees desired. After you have the correct setting,
and quarter lines. This establishes a base line for
further layout work.
When you are measuring, treat the surface of the
pipe as if it were a flat surface. Use a flat-steel rule or
tape, which will lie against the surface without kinks,
even though it is forced to follow the contour of the
pipe. These angles can also be checked for accuracy
by sighting with the square.
Use the protractor and square to determine the
proper cutback for the desired angle of the miter turn.
Start with the protractor scale set at zero so that the
flat surface of the protractor and the blade are parallel.
You can now set the protractor for the number of
lock the blade. Place the protractor on the square with
the bottom blade on the outside diameter of the pipe.
Now read up to the cutback on the vertical blade of the
square. You must be sure that the flat surface of the
protractor is flush against the blade of the square (fig.
3-47). The outside radius of the pipe should have been
determined during the quartering operation.
After you have obtained the cutback
measurement, mark one half of this measurement off
along the center line on top of the pipe. From the
opposite side of the base line, measure off the same