#gear

Hammock-hang maths as an API, computed locally and deterministically — the suspension-force, ridgeline and strap-height numbers a camper or hammock hanger sets up by. It all comes back to the 30-degree rule. The force endpoint shows why: the tension in each suspension line is the occupant weight ÷ (2 × sin of the hang angle), so at a 30° hang each strap carries about one body weight, but flatten the hang to 15° and it jumps to roughly 1.9 times — which is what over-stresses straps, trees and your back when people pull a hammock drum-tight. The ridgeline endpoint sizes a structural ridgeline at about 83 % of the hammock length, the fixed line that reproduces that ~30° lay and the right sag on any pair of trees. The strapheight endpoint estimates how high to attach the straps from the distance between the trees and the seat height you want, since trees farther apart need higher anchor points to hold the angle. Everything is computed locally and deterministically, so it is instant and private. Ideal for camping, backpacking, outdoor-gear and hammock app developers, hang-calculator and trip-planning tools, and adventure software. Pure local computation — no key, no third-party service, instant. Weight and lengths in your own unit. Live, nothing stored. 3 compute endpoints.

api.oanor.com/hammock-api

Spur-gear geometry as an API, computed locally and deterministically for standard full-depth involute teeth. The geometry endpoint takes a module and a number of teeth (and an optional pressure angle, default 20°) and returns the complete tooth geometry: the pitch diameter (module × teeth), the base, tip (outside) and root diameters, the addendum, dedendum, whole and working depth, the circular and base pitch, the diametral pitch and the tooth thickness — all in millimetres. The module can be given directly or derived from a diametral pitch or a circular pitch. The pair endpoint meshes two gears of the same module and returns each gear's pitch and tip diameter, the centre distance (module × (z1 + z2) ÷ 2) and the gear ratio. The module endpoint converts freely between module, diametral pitch and circular pitch, or derives the module from a pitch diameter and tooth count. Everything is computed locally and deterministically, so it is instant and private. Ideal for machine-design and CAD tools, gear and gearbox calculators, maker, robotics and 3D-printing projects, and mechanical-engineering apps. Pure local computation — no key, no third-party service, instant. Live, nothing stored. 3 endpoints. This is spur-gear geometry; for bicycle gear ratios and development use a bike-gear API and for belt-and-pulley drives use a belt-drive API.

api.oanor.com/spurgear-api