- Draw the blank size from the given shop drawing. Add the vertical and horizontal dimensions to calculate the blank
- Mark the openings on each end of the fitting. Remember to ALWAYS measure and mark the openings, not the throat
- Swing the throat radius. The throat remains the same as any other radius throat radius heel (RTRH) elbow
- Pick up the heel radius from the small end.
- Transfer this distance from the outside of the heel on the large end. It must be transferred from the outside, inwards to create a “square” for the heel section. From this new point, set you dividers to the heel and swing a 90° heel arc
- Calculate the heel length by using the small end radius, plus the straight section. The straight is the large end minus the small end.
- Calculate the throat as per normal.
- Bisect the heel and throat to find mid points
- Label the 6 points on the flat cheek A-F along with the actual amount of drop at that point
- Draw in element lines, connecting the labeling
- Create a True Length Diagram with ½ drop on the vertical leg
- Transfer all element lines which show a ½ drop into the TLD
- Triangulate the fitting, starting with baseline A-B and triangulate point C
- Triangulate until points E-F are established
- Using “Arc Through 3 Points” create the heel and throat arcs