arcspan.Measure the chord straight.
The chord connects the endpoints directly. A tape following the curved edge measures arc length instead, which is a different input.
Circular arc from chord and rise
Two measurements.
A curve to trace.
Turn a straight chord and its perpendicular midpoint rise into a minor circular arc. See the radius and length, mark chord stations, then save a calibrated centreline SVG or coordinate CSV.
Lay out your circular arc
CHORD · MIDPOINT RISE · MINOR ARC UP TO A SEMICIRCLE
02 / Your ideal centreline
· curved or straight length
- Circle radius
- Circle centre from chord
- Central angle
- Chord-station spacing
Fit-to-screen preview · not print scale
The saved SVG uses physical millimetres and includes a 50 mm calibration line. Print at actual size, measure the line, and test your layout. No automatic sheet tiling is included.
| Station | x mm | y mm |
|---|
Dimensions and station coordinates display up to 6 decimal places. This is ideal floating-point geometry, without material thickness or kerf.
One ideal minor circular centreline, including the semicircle and straight-line limit. This does not fit ellipses or irregular curves, calculate structural spans or loads, determine bending feasibility, or add material thickness, kerf or cutting offsets. Input decimals allow up to 6 places. SVG curves use a bounded polyline approximation; measurement, printer and cutter accuracy remain outside the model.
Take rise at the midpoint.
Use the perpendicular distance from the midpoint of the chord to the arc. Off-centre measurements do not describe this symmetric model.
Keep the reference line.
The station table uses the left chord end as x = 0 and the chord as y = 0. SVG millimetre scale and its printed calibration line make that reference traceable.