Eccentric reducer
Flat-on-one-side reducers. The triangulation is done for you: true lengths for every line, and every pattern point as a tape measurement off the baseline.
Inputs
From the Knauf chart, or type your own
From the Knauf chart, or type your own
0Small step-off (1/16 small circ.)
0Large step-off (1/16 large circ.)
True lengths
| Line | True length 1/16" | Decimal |
|---|
Pattern points, measured
| Point | Along baseline from 0 | Up from baseline |
|---|
Baseline runs from point 0 on the large end to point 0 on the small end (the flat side). Odd points are on the small end, even points on the large end.
Half pattern, to scale
- Draw the baseline the length of the fitting, . Left end is 0 (large), right end is 0 (small).
- Swing the small step-off above the right end and the 0-1 true length from the left end. Where they cross is point 1.
- Swing the large step-off from 0 on the left and the 1-2 true length from point 1. That is point 2.
- Keep going: small step-off from the last odd point and the next true length from the last even point, and so on to point 16.
- Join the points on each end with a smooth curve. That is half the pattern; flip it for the other half. Add notches, lap and safety edge.
Method: Advanced Metal Jacketing (IIIATF), Task C.2.2, Eccentric Reducing Bevel. Triangulation with 8 spaces on each half circle. Check the first piece on the job before cutting a batch.