Continued:
Widely used by the Denford's Small Tools Department, "Viceroy" was a marketing name that, by the end of the 1950s, was being attached to a number of different metal and wood turning lathes, edge-tool sharpening equipment, double-ended grinders and polishers, disc and belt-sanding machines, bench and pillar drills, drill sharpening machines, a metal shaper (originally the "Royal"), as well as two milling machines made for them by the A.E.W. Company in Norfolk. Wood lathes were offered in both between-centres and bowl-turning types and, in some cases, were adaptations of lower-specification metal lathes - the T.D.S.1.L.S. lathe being an example when, fitted with wood-turning equipment (including a  very heavily-built out-board bowl-turning attachment) it became part of the "Educator" range as the Model T.D.S.3.M.W. and advertised as a combined metal and wood lathe.
All the metal lathes were of 5-inch or (later) 5.5-inch  centre height and, without exception, carried on neat underdrive stands. Only two bed lengths were offered, giving either 24" or 40" between centres, the latter carrying the letter "L" as a suffix to its model number and being very rare.  Although hardly things of beauty  (and with some strange constructional details including being held together with a mixture of BSW, BSF, UNC and BA fasteners) they were very strongly-built, compact lathes designed, with great success, to appeal to the educational market as it existed in the 1950s and 1960. Although modelled closely on the general layout of a Boxford (with which it is sometimes confused) the Viceroy featured several significant improvements: a compact and safe underdrive stand, a more massive bed, 6.5 inches wide with larger V-ways and integral feet; a separate power-shaft for sliding and surfacing speeds with the leadscrew used for screwcutting only; a totally enclosed oil-bath screwcutting gearbox (which could be operated with the lathe running); single-lever engagement of backgear and a useful spindle lock for removing chucks (both features eventually to be fitted to the Mk. 2 Underdrive Boxfords); a rigid, doubled-walled apron (with an oil sump on the power cross-feed model) and, as a useful finishing touch, a tailstock barrel carrying a No. 3 Morse taper. The headstock spindle, like that on the Boxford, ran in taper roller bearings and had the same 1.5" x 8 t.p.i threaded nose but with a fractionally larger bore of 13/16". The headstock was unusual in that (on backgeared versions) the final drive was not direct by belt but geared down slightly by passing through a supplementary gear arrangement in the headstock, making the lathe rather noisier than it should have been - and providing yet one more thing to wear out or go wrong.
From thoroughly well-specified metal lathes to both simple wood-turning and combination wood-turning and inexpensive plain-turning metal lathes the company generally used the same basic casting for bed, tailstock and elements of both headstock and carriage - thus saving both a great deal of money and simplifying the provision of spares. Although the lathes altered in detail over the years from any one era the aim was always  to make the design as modular and interchangeable as possible. The T.D.S.-4 and T.D.S.-5.B.G. were both entry-level models with the No. 4 having just belt drive and the No. 5B.G. the addition of  backgear. The T.D.S.-1 had screwcutting by changewheels and hand-powered cross feed while the top-of-the-range T.D.S.-1/1-G.B. was fitted with a screwcutting gearbox and a separate power shaft to provide sliding and surfacing feeds. An important part of the gearbox screwcutting arrangements, and vital to extend the threading range, was a set of extra 14DP changewheels, mounted on a stud behind the gear-train quadrant, and stamped: A = 16t, B = 18t, C = 22t, D = 24t, E = 26t, F = 27t and G = 35t.
All models were mounted on underdrive cabinet stands that took up a minimum amount of room - just 17" or 18" deep front to back and around 54" long in standard bed-length form. A  0.75 h.p. 3-phase motor was standard, with the option of 1.5 h.p. when used industrially rather than educationally with, in the case of T.D.S.-1/1-G.B (and in conjunction with its single-lever-engaged backgear) eight spindle speeds from of: 75, 110, 175, 250, 400, 570, 900 and 1300 rpm to 1400 r.p.m. On  Mk. 2  models the speeds became: 60, 85, 135, 200, 410, 570, 930 and 1350 rpm. Surprisingly, for a lathe intended to teach the basic of turning, the bottom speeds of  60 rpm was still too fast for screwcutting and, if this had been reduced to below 40 r.p.m., it would have made the machine much more suitable for its intended customers. In conjunction with an 8 t.p.i. leadscrew the screwcutting gearbox provided 48 threads from 4 to 224 t.p.i and 26 power feeds, the longitudinal rate varying from 0.0014" to 0.0118" and the cross from 0.0005" to 0.0046". On the Mk. 2 these rates were changed to become: sliding feeds 0.0014" to 0.08" and surfacing 0.0005" to 0.3".
Robustly constructed, with the usual set-over facility for turning shallow tapers, all tailstocks used a No. 3 Morse taper (the competing Boxford was always limited to a No. 2) with around 3" of travel and, unusually for a lathe of this size, a spindle bored through 13/16" that passed clear through the casting and handwheel.
With the carriage and tailstock reflecting the "round" lines common in the 1930s and 1940s - but headstock and screwcutting gearbox with a distinctly more modern angular look - the original style of the Viceroy was interesting  However, by the 1960s, the range had distinctly old-fashioned air about it and, to keep it looking fresh, Denford introduced a Mk. 2 version. Although some mechanical changes were made (and the speed ranges altered)  it seems that the real extent of the re-design was to dust off the original blueprints, replace every curved line with a straight one and make new patterns. However, an easier-to-use improved oil-bath power-feed apron incorporating an adjustable automatic knock-off was introduced - though the widespread use of plastic-coated metal handles secured by just spring-dowel pins was not so praiseworthy. In later years various models of these newer machines became available, from plain-turning to more highly-developed and generously-specified 280 and "Synchro" models fitted with manual or electrically-operated variable-speed drive.
Viceroy machine tools were rarely advertised in other than the educational press and are still little known, even in their country of origin; consequently, the market under-values them and, if you want a neat, strong, very compact lathe with a generous capacity at a bargain price - a Denford Viceroy may be the machine to look for ..

Mk. 2 Viceroy T.D.S.1/1   5.5" x 24" This distinctive machine was Viceroy's final conventional lathe which, although styled in an up-to-date fashion (and of an improved detailed specification including an automatic knock-off for the carriage sliding feed), closely followed the mechanical details of previous designs with many parts being interchangeable. Various specifications were available, from plain-turning to highly-specified 280 and "Synchro" models fitted with manual or electrically-operated variable-speed drive.

A rear view of the headstock showing the "single-lever" backgear mechanism, the drive out to the changewheels and the micro-switch (top) that stopped the lathe if the changewheel cover was opened - though most schools took the additional precaution of bolting them closed - just in case).
A tip if you ever change the link drive belt: before fitting thoroughly clean out the tunnel though which it runs and, even then, to stop contamination by grease, wrap the new belt in tape which can be removed once in place. Don't remove the old belt first - join the new one to it and pull through.

Plain apron as fitted to the Mk. 1 Viceroy T.D.S.4.B.G. and T.DS.4 plain-turning training lathes .

Mk. 2 Viceroy T.D.S. lathe showing the neat storage for the extra changewheels, an important part of the gearbox screwcutting arrangements, and vital to extend the threading range. The 14DP gears were stamped: A = 16t, B = 18t, C = 22t, D = 24t, E = 26t, F = 27t and G = 35t.
In the middle of the gear train can be seen the sliding gear that was used to change between threads and fine feeds and, at 11 o'clock, the spindle locking mechanism. Note the cut-off tumble-reverse lever with its spring indent working against the outside face of the headstock - it was thus locked away safely inside the changewheel guard, away from curious fingers.

The main motor drove a small suds pump in the back of the cabinet and up to an intermediate countershaft held in an ingeniously-simple yet adjustable housing. The final drive was by link belting.