Given a number of confusing model numbers, Denford's range of less-expensive lathes intended for the education market was based upon a single 5" x 24" or 40" machine very similar to the original TDS 1/1 - but usually without the power shaft for sliding and surfacing feeds, and often without backgear and screwcutting. Like all Viceroy lathe, spindles ran in taper-roller bearings with the nose carrying a 1.5" x 8 t.p.i. thread; when fitted with a bowl turning attachment, the left-hand (outboard) end of the spindle was threaded 1.5" x 9 t.p.i. left-hand - this specification applying to the TDS6 dedicated wood-turning lathe (and its various sub-models), the "Educator" and its replacements, the TDS3, TDS SM.W and Model 250..
Most frequently encountered model of the genre is likely to be the original "Educator", a dual-purpose wood and metal lathe that was produced in several forms with most supplied in a very basic, plain-turning specification (the code for these was T.D.S.4). However, others were more comprehensively equipped with backgear and screwcutting (usually coded T.D.S.1) - while others even appear to have been little more than price-reduced machines from the main range. Although some carried badges proclaiming Educator others did not - though the Model type can generally be found stamped (as part of the Serial Number) into the tailstock-end of the bed. All appear to have shared a common headstock assembly, some with 4 belt-driven speeds, others with 8 of 60, 85, 135, 200 in backgear and 410, 570, 930 and 1350 in direct belt drive. Early models had motors listed as being either 0.5 or 0.75 h.p. though later versions were all catalogued with a 0.75 h.p. (3-phase or single phase) with 1.5 h.p. as an extra-cost option. In addition, a number have been found with a slightly different range of 75 to 1300 r.p.m., probably a result of using up unwanted parts from the spares department. A push-button starter and Dewhurst reversing switch, both built in flush to the front face of the stand, were part of the ordinary electrical equipment. The late (and seldom-seen) T.D.S.1.L.S., Type 250 and Mk.2 T.D.S. 3M.W lathes were the most highly-specified versions with backgear and screwcutting, though these often lacked the large bowl-turning unit seen on many of the other models. A few were fitted with a most odd arrangement for the carriage drive that used either a belt or chain - the latter a method resurrected from the Victorian era and as seen, for example on the American Shepard lathe - though it did occasionally surface in the 20th century with examples including some cheaper models of Czechoslovakian Volman lathes and also the British Jen-son - though the latter was really rather different in design and function. The drive on some versions of the "Educator" range incorporated a dog clutch on the leadscrew, allowing it to be quickly flicked in and out of engagement by a lever positioned in the lower right-hand corner of the headstock's front face. The T.D.S.5.B.G. was backgeared but with the power feed removed and the T.D.S.3.M.W. a special plain-turning metal lathe fitted with an outboard bowl-turning rest adapted from the T.D.S.6.W.L. dedicated wood lathe. This lathe was also sold, in late form, badged as the Model 250, though so far no examples have been found with screwcutting - a shame, as such a machine, being able to manage a wide variety of tasks in one compact and reasonable-priced package would, if offered on the model-engineering, home or small repair-workshop market, have sold rather well. T.G.S.5 GB photo Essay
If you have one of the more unusual combined wood and metal lathes - especially if fitted with the chain or belt drive - the writer would appreciate photographs to include in the Archive..