About

21Geo — you will increasingly see this work under its newer name, Roll — is the invention of Tom Dobroth. What began as an investigation into low-loss transmission became something broader: the rolling interface, a machine element that delivers a specified motion through pure rolling contact. The same mechanism now underlies a family of work — speed reducers first, with rolling-contact bearings and further configurations in development.

Where things stand: two US patents granted — rolling-contact bearings (US 11,692,613) and the rotary speed reducer (US 12,398,784) — with one application pending. A 3D-printed reducer assembles and turns under hand input, demonstrating the kinematics; instrumented efficiency and wear testing is the company's next phase. We are seeking partners with the test capability to measure the reducer against a geared reduction of equal ratio — and that is the collaboration we most want to hear about.

Tom holds bachelor's and master's degrees in mechanical engineering from MIT. His master's work estimated the shapes of free-surface flows — computing curves nature insists on; today he estimates raceway shapes that deliver pure rolling — computing curves a motion insists on. Between the two, he has worked across Silicon Valley in engineering, project and product management, and sales, on both sides of the table where technology meets its market.

Away from machinery, Tom is a lifelong competitive sailor — a winner of many regattas and season championships, happiest racing San Francisco Bay in a stiff breeze, and an unrepentant charterer of sailboats in warm places.