Wood turning
Segmented turning from a vessel profile — rings by height, segments per ring, mitre angle, segment lengths and widths, strip length with kerf, a staggered brick pattern, feature rings, ring plans, a side view and a printable cut list — plus lathe speed by diameter, stave construction angles for straight and tapered vessels, and turning blanks from a log.
Added
Works with
- Woodworking angles and fractions Woodworkingpolygon and compound mitres for frames and splayed boxes use the same geometry as rings and staves
- Board feet and lumber Woodworkingprice the strips and board feet from the cut list
- Wood species Woodworkingchoose contrasting woods that turn well
How to use it
Calculations for the lathe, in inches (with fractions) or millimetres — the units are shared with the other woodworking tools.
How to use it
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Segmented. Describe the vessel by its outside diameter at heights from the base (a vase to start with), or drag the dots on the side view to reshape it. Set the finished wall thickness, the ring height (the thickness of the boards you will cut segments from), an optional solid base disc, and a turning allowance left on each face. The tool slices the profile into rings: each ring is sized to the widest outside and the narrowest inside within its height, plus the allowance, so the finished shape lies inside the glued-up blank. For each ring you get the number of segments, the mitre angle (180° ÷ N from square, on each end), the outside and inside lengths of the trapezoid, its width, and the length of strip to cut them from including the saw kerf. Rings near the bottom that are almost solid become discs.
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Feature rings. Pick a ring number and give it its own segment count and a pattern: a contrast band in wood B, alternating A and B, every third segment in B, or veneer spacers in every joint (the segments shorten by the spacer thickness). Stagger joints turns each ring half a segment from the one below, for the brick pattern; the side view shows the joints as they will appear, and the ring plans show each ring from above with the finished inside and outside circles.
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Cut list. Every ring by wood, with base and disc sizes and spacer veneers, totals per wood in strip length and board feet. Print cut list opens a printable page with the drawing; CSV downloads it for a spreadsheet.
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Lathe speed. The common rule: diameter in inches × rpm between about 6000 (start, out of round) and 9000 (balanced, finishing), capped at your lathe’s maximum and at 4000 rpm, with surface speed and a table by diameter.
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Staves. For a coopered canister or bucket: number of staves, finished diameters at the bottom and top, height and wall. A straight vessel needs an edge bevel of 180° ÷ n; a tapered one needs a slightly different bevel, which the tool finds from the 3-D geometry, along with the stave widths, thickness, length and the taper to cut on each edge.
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Blanks from a log. Log diameter and length, the strip removed through the pith, bark and end checks: how many side-grain bowl blanks of what size and thickness come from the two halves, and how many spindle squares fit around the pith, drawn end-on and from above.
How it works
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Segment geometry: for N segments the outside edge sits at the ring’s outer radius R, so it is 2·R·tan(180°/N) long; the inside corners touch the inner radius r, so the inside edge’s apothem is r·cos(180°/N). Width = R − r·cos(180°/N). The tests check a 12-segment ring of 100 mm outer and 80 mm inner radius (53.59 mm outside, 41.41 mm inside, 22.73 mm wide) and that the segments' angles add up to 360°.
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Strip length: N × (mid length + kerf ÷ cos(mitre)), one end triangle, plus a handling allowance.
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A sloping wall is thicker measured across than square to its surface; the inside of each ring uses the horizontal thickness, wall × √(1 + slope²).
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Tapered staves: the bevel is the angle between a stave’s face and the radial plane through its edge, measured square to the edge. With vertical sides that is 180° ÷ n; the tests check that a four-sided frustum leaning 45° gives the same 30° as the compound-mitre formula for a splayed box.
Limits
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The profile is joined by straight lines between points; add points where the curve is tight.
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Ring sizes assume the blank is centred perfectly. Leave more allowance for a first project.
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Lathe speeds are a rule of thumb from turning clubs and lathe manuals, not a guarantee that a particular blank is safe at that speed. Cracked, unbalanced or glued-up blanks need less.
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Blank yield ignores defects, cracks and the taper of real logs.
Linking to an example
Share link copies a URL with your settings. Lengths in links are in millimetres; the profile is
height:diameter pairs separated by commas and feature rings ring:segments:pattern (pattern
plain, b, alt, k3 or spacer) — for example
?n=16&feat=3:32:alt.
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Profile, e.g. |
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Wall, ring height, base disc thickness, allowance per face (mm) |
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Segments per ring, feature rings, stagger |
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Saw kerf, spacer veneer thickness, extra strip length (mm) |
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Names of wood A and wood B |
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Lathe speed: blank diameter (mm), lathe maximum rpm |
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Staves: count, bottom and top diameters, height, wall (mm) |
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Log: diameter, length, pith strip, bark loss, end checks, bowl blank size, spindle square (mm) |
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Presets (?example=<name>):
example= |
Shows |
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