Rebuilding the Original Odhner Model 127 Pinwheel Calculator
John Wolff's Web Museum offers a detailed step-by-step guide to completely disassembling and reassembling the Original-Odhner Model 127 mechanical calculator. The Odhner 127 is a relatively simple machine, ideal for learning the principles of all pinwheel calculators. The notes, refined over many rebuilds, cover disassembly, cleaning, and reassembly, with practical tips and warnings. They are meant to be used alongside a technical description of the pinwheel mechanism and general overhaul notes.
The Odhner 127 is a relatively simple and straightforward machine, and is an ideal place to learn the principles on which all pinwheel calculators are based.