Manufactured by David W. Onan of Minneapolis, Minnesota U.S.A. and carrying a patent date of Sept. 17, 1916, the 3.5" centre height by 15" between centres Onan is now a very rare machine. Obviously intended for light-duty metal and wood turning, its construction was a fine example of how to build a basic but sturdy lathe at little cost: the bed bars were lengths of what must have seen standard, commercially available square-section steel bar socketed into robust cast-iron housings at the headstock and tailstock ends
Fitted with a screw-driven cross slide, the longitudinal feed was obtained by sliding the whole carriage along the bend under the control of a large lever that carried, cast into it, the David Onan name, a 1916 patent date and the words "spring spreader". The position of the lever's pivot mechanism (a rather flimsy-looking clamp around the bed) could be adjusted to suit the position of the work in hand, the assembly being locked by a simple wing nut.
Running in plain bronze bearings, the headstock spindle was lubricated though a reservoir covered by a bronze or brass plate - the terse instruction Oil Here being engraved into its surface. The drive system was of the simplest kind possible, an overhung pulley designed to take a round leather "gut" rope. However, some versions of the Onan have been found with a rather unusual fitting - a simple if not crude friction-drive arrangement with a large bronze operating lever arranged to straddle a ball-race collar that bore against hub of the drive pulley. The collar was formed with a groove around its periphery into which two tangs on the operating arm fitted. The outside of the pulley pushed against a bronze washer that was anchored to the drive shaft (with a single set screw) - the effect being to create the same sort of action as found in the pressure-plate assembly of an automobile clutch.
Of the simplest possible kind, holding a sliding spindle secured by split clamp, the tailstock could not be used for drilling and merely provided a support for the end of long work.
Some examples of the Onan have been found with both bed rails set edges upwards and others arranged so that one edge was up and the other to give a flat, horizontal surface - though both carried the same brand of 3-jaw chuck as the others (by Leavitt ) the same brass tag over the spindle oil point, identical carriage fittings and the same feed lever.
If you have an Onan, or any information about the maker, the writer would be interested to hear from you.