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CNC Nesting & Programming Guide By Mal Moran

This presentation will demonstrate how using various nesting techniques can help improve the

efficiencies of a CNC program.

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A Nested PairIf a part is shaped then a nested pair should be considered to

reduce waste between the parts. The CNC programmer of this program has not produced a nested pair?

Note how the increment has not been reduced leaving a gap of 32mm instead of 5mm?

Total waste = 27.9%

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A Nested Pair

By producing a nested pair the waste of this program has been reduced by 9.9%

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Comparison

Prog Length Width Height No.Prod Waste % Ord Qty M3VX12811 2065 1926 992 496 27.9 464 3.69Mal12 2068 1691 992 496 18 464 3.25

9.9 0.45 0.45

Waste reduction = 9.9%

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A Nested Pair

This is a common way to create a nested pair. Depending on the shape of a part the CNC programmer should always be

thinking of the most efficient nest / program.

Is this the most efficient nest for this part?

Nested waste = 27.5%

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NO!

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Stagger Nesting

Staggering or off setting a nested pair should always be considered to reduce waste when creating a CNC program. Complex shaped parts can require careful attention when

creating a program.

Nested waste = 12%

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Prog Length Width Height No.Prod Waste % Ord Qty M3VX9953 1823 2196 1000 13944 32.5 574 0.16Mal4 1936 2092 1000 16932 18.6 574 0.14

13.9 0.03 0.03

VX9953 Mal4

Comparison

Waste reduction = 13.9%

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Stagger Nesting Comparison

Prog Length Width Height No.Prod Waste % Ord Qty M3VX13306 1591 1726 1000 160 21.3 466 8.00Mal10 1252 1905 1000 160 9.4 466 6.95

11.9 1.05 1.05

Waste reduction = 11.9%

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A Nested Pair Program

The CNC programmer of this program has created a nested pair and has reduced the increment to the next nested pair.

Is this the most efficient nest?

VX13374

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NO!

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Rotate Nesting

Rotating a nested pair and reducing the waste between the increment should also be considered when creating a CNC program.

The yield from a sheet / block could also improve.

MAL1

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ComparisonVX13374

MAL1

Prog Length Width Height No.Prod Waste% Ord Qty M3VX13374 2272 1658 1000 30 48.3 99 12.43Mal1 2100 1982 1000 40 39.7 99 10.30

8.6 2.13 2.13

Waste reduction = 8.6%

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Summary

A nested pair can in most cases produce a more efficient program.

Consider the scrap between parts and reduce the increment where ever possible.

Staggering or rotating the parts could help to further reduce scrap and improve the yield from a sheet or block.

Consider the block size / window when creating a CNC program. Try to maximise a window of a block where ever possible.