Oval to Round

Page 104

Oval to Round

Information Required: oval dimensions with

insulation included, round dimensions, true

height

Step 1: Draw a plan view of the fitting.

Step 2: Trisect and label the small circle as

shown.

Step 3: Trisect and label the bottom ¼

circles of the oval

Step 4: Draw a 90-degree angle and take

the measurements for the slant heights.

These measurements are taken from 5 to 1,

1 to 6, 6 to 2, 2 to 7, 7 to 3, 3 to 8 and 8 to

4. Place all these measurements on the

horizontal line and label as shown.

Step 5: Start the stretch-out by drawing a

horizontal line equal to the distance from 8

to 8 on the plan view.

Step 6: From the slant heights set dividers

from the apex to the 8-4 point and transfer

to the stretch-out by using point 8 as an

apex and swing arcs that will intersect to

acquire point 4.

Step 7: From the plan view set dividers from

1 to 2 and on the stretch-out set the

dividers on point 4 and swing an arc to each

side.

Step 8: Return to the slant heights and set

the dividers from the apex to 8-3 point and

on the stretch-out, using point 8 as an apex

swing intersecting arcs to form point 3 on

the stretch-out.

Step 9: From the plan view, set dividers

from 7 to 8 and swing arcs to the outside of

both points 8.

Step 10: from the slant heights set your

dividers at 7-3 point and transfer this

measurement to the stretch-out using point

3 as an apex. This arc will intersect to form

point 7.

Step 11: continue this formula to obtain all

the points for the layout.

Step 12: Connect points, laps and notches

to obtain half the layout.