WRAP LOGIC FIELD GUIDE
Jacket layouts

Rectangle to rectangle

Concentric duct transitions. Enter the two rectangles and the height; it gives you each face as a flat trapezoid with its true height.

Inputs

Actual size including insulation
Matches large side 1
0Corner true length
0Corner lap

Faces

FaceLarge edgeSmall edgeTrue height

Each face is a flat trapezoid: large edge at the bottom, small edge centred on top, true height square between them. All four corners come out the same length.

Stretch-out, to scale

  1. Lay out the side-1 face in the middle: large edge on the baseline, small edge centred above it at the true height.
  2. Add a side-2 face on each side, sharing the corner lines.
  3. Add the second side-1 face on one end.
  4. Add a 2" corner lap parallel to the last corner line. Add laps to the large and small ends if you need them.

Method: Advanced Metal Jacketing (IIIATF), Task D.4, Rectangle to Rectangle (concentric). Corner lap 2" per the manual. Check the first piece on the job before cutting a batch.