Nesting parameter to set a cost for offcuts produced
The offcut allowance is a percentage of the original board cost and this determines how much an offcut is worth when comparing patterns during the optimisation. To favour large offcuts rather than small ones a larger allowance should be set for maximum size offcuts.
e.g.
Offcut allowance for minimum size offcut = 30%
Offcut allowance for maximum size offcut = 100%
The maximum size offcut is the largest board size for that material in the run and the minimum size offcut size is the smallest offcut allowed by the parameters. The maximum and minimum percentages are associated with these two sizes and all other offcut sizes are then allocated a percentage based on this range.
For example, using the offcut allowance values above:-
Maximum offcut size = 2440 x 1220mm
Minimum offcut size = 500 x 500mm
Board cost = 4.25m2
Offcut size range (m2) = 2.97 – 0.25 = 2.72m2
Offcut allowance range = 70-30 = 40
Percentage points per m2 = 40/2.72 = 14.71
What is the offcut allowance for offcut 1000 x 800mm ?
Size of offcut above minimum size = 0.8 – 0.25 = 0.55m2
Percentage above minimum offcut allowance = 0.55 * 14.71 = 8.09
Offcut allowance = 30 + 8.09 = 38.09%
Value of offcut = 0.8 * 4.25 * 38.09% = 1.32
Notes
- Rectangular Nesting and Shaped Nesting II only
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