Backgear Type 3 - full-width clamp-on with tennoned bearing housing
An early Round Bed fitted with another type of backgear conversion, this time held on with two bed clamps with each carrying a separate bolt-on and tennoned bearing housing. Being made during the 1930s, this conversion took advantage of a Z-section 3-step V-belt drive - unfortunately, the clamp in front of the headstock meant that only a smaller face plate than standard could be fitted. Never seen before, this lathe has a quite different design of tailstock that allowed a little more capacity between centres.

Backgear Type 3  - this version has each backgear bearing housing formed as a separate casting bolted and tennoned to its the bed-clamp section

Backgear Type 4
Similar to the Type 1 but with the spindle-shaft section formed as press fit in upper section of the clamp-on housing rather than a bolt-through unit.

Type 5 backgear
Similar to the other third-party offerings this was a more economical unit and carried on a bed-mount held in place by a crude through bolt. It was fitted with a through shaft that held a small gear on its outer end and a larger one on the inner - the latter engaging with a small gear on the spindle positioned between the pulley and left-hand bearing and the small gear with a standard changewheel mounted on the end of the headstock spindle..

The Walram in use to provide a left-hand threading drive to the leadscrew. It could also be assembled to give an ultra-fine carriage feed by means of an additional compound reduction where two gears--one large and one small--are pinned together on a common shaft. Normally the Round bed would have been limited to two such assemblies but with the Walram in place three could be fitted

The Walram arranged to drive the headstock spindle through gearing - though as arranged in the picture the final speed would have been little different to a direct drive. To obtain a reduced speed a compound train would have been needed i.e. a small gear would have been fitted to the top shaft driving a large gear beneath to which would have been pinned a second gear driving to a large gear on the end of the spindle

Round Bed with backgear as found in Australia

Yet another different backgear attachment for a Round Bed Drummond, this one listed as the Type 6 and probably offered in the mid to late 1930s. The assembly is all cast iron, including the V-belt headstock pulley, and was originally secured in place by bed clamp to the right of the headstock. Like the type 6 shown above, this reduced room beneath the spindle nose and meant that only a smaller than standard faceplate could be used. To solve this problem, the new owner has modified the clamp to fit to the left of the headstock.
The previous owner, presumably when he fitted the backgear, had bored out the front bearing from 1" to 11/4" diameter, so the opportunity was taken to fit a new spindle with a Myford Series 7 spindle nose,  threaded 11/8" x 12 t.p.i., bored through 5/8" and fitted with a No. 2 Morse taper. An ML7 tailstock barrel has also been fitted - reported as being an easy swap - this giving a usefully both longer travel and, again, a No.2 Morse taper. Graduations have been engraved on the leadscrew and cross slide handwheels and the leadscrew fitted with needle-roller thrust bearings. Surprisingly, a tumble-reverse mechanism, one intended for the Drummond M-Type was a straight fit and makes the lathe so much easier to use. Despite the alterations, the lathe still retains all the vintage appearance and charm of a standard Drummond Round Bed.