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Weaving Calculations · Lecture 25
Set Size Planning
For every quality on the loom plan: beams per set, ends per beam, cone length, sets of warping required and bags of yarn to issue.
SetsEnds per beamCone lengthBags
What a “set” is
A set is one full creel of cones warped onto the required number of warper’s beams, then sized onto weaver’s beams. The size of the set is fixed by the cone: a 4.17 lb cone of Ne 20 holds 4.17 × 840 × 20 = 70,056 yd, less 2% wastage. Each loom gets a sized beam of a given length; multiply by looms and by beams per set to get the yardage the cones must supply, and divide by the yardage per cone to get the number of sets.
length per cone = cone lb × 840 × Ne × (1 − wastage) · sets = beams × looms × sized length per beam ÷ length per cone · bags = ends per beam × sets ÷ 24
How long a sized beam can be comes from the beam volume (Lecture 7) and the yarn diameter d = 1/(26√Ne) inches: the yarn cross-section × ends × length cannot exceed the beam’s volume.
Set size worksheet
| A | B | C | D | E | F | G | H | I | J | K | L | M | N | O | P | Q | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 1 | Quality | Looms | EPI | Width | Warp Ne | Wastage | T. ends | Beams | Ends/beam | Yd / cone | Yd / sized beam | Yd to size | Cone yd reqd | Sets | Sets used | Bags | Actual yd/beam |
| 2 | Cone size (lb) → | Beam yarn volume (in³) | |||||||||||||||
| 3 | 20×16/128×60, 63" | 8,064 | 10 | 807 | 68,655 | 2,319 | 13,911 | 139,111 | 2.03 | 2 | 68 | 13,731 | |||||
| 4 | 30/2×40/2/96×48, 51" | 4,896 | 6 | 816 | 51,491 | 2,864 | 5,728 | 34,369 | 0.67 | 1 | 34 | 8,582 | |||||
| 5 | 20×7/128×44, 51" | 6,528 | 8 | 816 | 68,655 | 2,864 | 17,184 | 137,475 | 2.00 | 2 | 68 | 17,164 | |||||
| 6 | 20×10/118×52, 63" | 7,434 | 10 | 744 | 68,655 | 2,515 | 30,180 | 301,800 | 4.40 | 5 | 155 | 34,327 | |||||
| 7 | 16×12/108×56, 63" | 6,804 | 10 | 681 | 54,924 | 2,198 | 26,380 | 263,796 | 4.80 | 5 | 142 | 27,462 | |||||
| 8 | 20×20/108×58, 63" | 6,804 | 10 | 681 | 68,655 | 2,748 | 32,974 | 329,745 | 4.80 | 5 | 142 | 34,327 |
blue = input (edit me)grey = formula (click to see it)
A set that works out to 2.03 is rounded down to 2 (the 0.05 allowance) — the beams simply come out a little shorter. 24 cones of 4.17 lb make one 100 lb bag. The sized-beam length is computed from the beam volume; the lecture read the same figures (2,320 yd for 8,064 ends of Ne 20) from a maximum-volume table on its second sheet.
Original lecture material
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