PROBLEM II--Lay out a seven-hole flange. (See

SOLUTION:

fig. 16-6.)

1. Draw a circle of the required diameter (AB) and

SOLUTION:

construct CD perpendicular to AB at center point C.

1. Draw a circle with the required pitch diameter

2. Bisect line AC, locating point E. Then with E as

(AB). Then construct a line that bisects and is

a center and distance ED as the radius, draw arc DE

perpendicular to radius CB (point D). Extend this line

3. With D as the pivot point and distance DF as a

until it intersects the circumference at E and F.

radius, scribe arc FG. Distance DF (or DG) is the length

2. With F as the center and distance DF as a radius,

of the pitch chord and one-fifth of the circumference of

locate point G. Distance FG (also FD and DE) is

the circle. Step off this distance (DF) around the

one-seventh of the circumference or the true length of

circumference. Points G, D, H, I, and J are centers for

the pitch chord. With the dividers set for this distance,

the holes of a five-hole flange.

step off the circumference and locate points F, G, H, I,

If you step off the circumference using

J, K, and L. These points are the centers for a seven-hole

measurement GB instead of DG, you get a 20-bolthole

flange of the given pitch circle.

flange. Each spot where your dividers make an arc on

the circle's circumference will be the center point for a

PROBLEM III--Lay out a nine-hole flange. (See

bolthole.

fig. 16-7.)

16-7