KEVOS® MAKEOS · Fabrication
Three-Size Stock Cut Planner
How can these pieces fit into equal-length stock bars?
Build a feasible longest-first plan for three part lengths, with end trims, kerf, offcuts and bars to purchase.
Open the calculatorRuns in your browser. No account needed.
How this tool works
Inputs, units and where to find them
| Input | Unit | Typical source |
|---|---|---|
| Stock bar length | mm | Purchased full-length stock before end trims; all bars use this length. |
| End trim at each end | mm | Length removed at each end, including any trim-cut loss not covered by per-piece kerf. |
| Kerf per finished piece | mm | One kerf per finished piece including the last piece: deliberately conservative. |
| Part 1: finished length | mm | Required cut length including any later machining allowance. |
| Part 1: required pieces | pieces | Whole pieces of this length, up to 100; use 0 to omit this part. |
| Part 2: finished length | mm | Required cut length including any later machining allowance. |
| Part 2: required pieces | pieces | Whole pieces of this length, up to 100; use 0 to omit this part. |
| Part 3: finished length | mm | Required cut length including any later machining allowance. |
| Part 3: required pieces | pieces | Whole pieces of this length, up to 100; use 0 to omit this part. |
| Bars already available | bars | Identical full-length bars already available; shorter offcuts are excluded. |
Method and formulas
- Enter lengths to at most three decimals in millimetres; calculations use integer micrometres. Usable length is stock minus two end trims.
- Sort pieces longest first and place each into the first bar with room for its length plus one kerf, starting another bar when necessary.
- The ceiling of total piece-plus-kerf length divided by usable bar length is a material lower bound. Matching this bound proves minimum bar count in this model; otherwise the plan is only feasible.
- Example: 1000 mm stock, 5 mm each end and 2 mm kerf, with six 250 mm, four 180 mm and four 90 mm pieces needs 3 bars. Parts = 2580 mm, kerf = 28 mm, trims = 30 mm, offcuts = 362 mm. With 2 bars available, purchase 1.
Limitations
- At most three lengths and 100 pieces each. Mixed stock sizes, mitres, defects, clamping length, shared cuts and reusable offcut inventory are excluded.
- First-fit decreasing is a heuristic. A plan above the lower bound is not claimed optimal.
- One kerf is reserved per finished piece, including the last. End trims include their own cutting loss.
- Default values are worked examples, not recommended settings or material properties.
Typical uses
- cut stock
- saw cutting plan
- material yield
Who it is for
- Fabricators
- Estimators
- Workshop planners
What you get
- Per-bar cutting list
- Required bars and purchase quantity
- Parts, kerf, trims, offcuts and yield
Interpreting the result
- Check each pattern, stock specification and machine allowances before cutting.
- Yield is finished part length/gross stock length. No reuse value is assigned to offcuts.
References
- Method: original first-fit decreasing implementation with integer length accounting and a material lower bound.
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