0 · TEST LOADER (temporary)
1 · Job
2 · Start of run
Sizes in even inches, W×H. The run builds from here piece by piece.
3 · Build the run — piece by piece
FOB
flat bottom · field std
FOT
flat top
CONCENTRIC
all sides split it
FLAT LEFT
plan · right wall moves
FLAT RIGHT
plan · left wall moves
SQ → ROUND
Ø goes in width
The type changes the math: FOB puts the whole height change on ONE side — steeper than concentric for the same length.
Rise AND shift = ONE compound piece: top/bottom take the rise, the cheeks take the shift. Math shows the true throw.
Radius wants R = duct width. Square throat gets vanes — single rail ≤20" wide, double past that (VERIFY shop std).
Builds it like the field: 45 up · run flat past it · 45 back down. The elevation view shows the hump; the math shows the true lengths.
Round spiral runout off the tap · 90 at the drop · flex allowed only for the last bit, pulled tight.
Measured from the TAP, not from A — the spiral tee splits the runout cut.
Adds the elbow + vertical pieces at trunk size. Shows as DN on the plan — just like the drawings.
CHANGEOUT — unit swap adapter (measure both ends, get the spec)
The service killer: new unit collar on one end, the OLD plenum opening on the other — nothing matches. Measure both, measure the gap, say which sides must stay flat. It hands you the adapter spec with the slope check.
Duct is shop-fabbed, not stick-cut. The send IS the product: field → fab in one shot.
PLAN — SINGLE LINE, like the drawings the old-timers read: route · turns · taps · drops (A → B)
ELEVATION — side view: heights, offsets, rises
DETAILS — the blowups: every fitting’s own card (single line carries the route, these carry the meat)
Transitions, offsets, dodges and elbows land here with their numbers.
The Math — shown, like always
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Piece List — connection allowances applied
| Mark | Piece | Size | Sheet-cut length | Ga |
|---|---|---|---|---|
| Waiting on the run… | ||||
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