Mk. 1 Viceroy T.D.S .1/1-G.B. lathe of the early 1950s fitted with a full screwcutting gearbox and a separate power-shaft for sliding and surfacing feeds. This lathe, with its safely enclosed drives and full guarding, was designed for the educational and training market

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. In addition Denford sold a wide range of equipment designed for schools and colleges including the Sharpedge T.D.S. 12/16 and T.D.S. 12/10 edge-tool sharpening machines; T.D.S. 8 and T.D.S. 9 and T.D.S. 10 double-ended grinders and polishers; T.D.S. 25 Models D and B disc and belt-sanding machines; bench and pillar drills listed as the Types T.D.S.22, T.D.S. 22-BG, T.D.S. 23 and T.D.S. 23-BG (the BG types being backgeared with a useful range of slow speeds); the drill-sharpening machine Type T.D.S.29; a metal shaper (originally the "Royal"); two milling machines, a vertical and horizontal made for them by the A.E.W. Company in Norfolk; T.D.S. 17 and T.D.S. 20 brazing hearths and T.D.S. 14 and T.D.S 15 gas/air forging hearths, potters wheels and mechanical donkey saws by Wellsaw.
Wood lathes were offered in both between-centres and bowl-turning types being, in some cases, 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. Later models included the more advanced Synchro, 280 & Enterprise and the rather confusingly named T.D.S.-1.L.S., T.D.S.5.G.B., T.D.S.3.M.W. Educator & Types 240 and 250. 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" (600 mm or 1000 mm) between centres, the latter carrying the letter "L" as a suffix to its model number (or labelled as the Type 2/1) 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) these were very strongly-built, compact lathes designed, with great success, to appeal to the educational market as it existed in the 1950s and 60s. 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 deeper 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 lubricated 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 Boxford); a rigid, doubled-walled apron (with an oil sump on the power cross-feed model) and, as a useful finishing touch, a tailstock barrel with a No. 3 Morse taper socket. 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; unfortunately, this arrangement made the lathe rather noisier than it should have been - and providing yet one more thing to wear out or go wrong.
Extending across a range consisting of thoroughly well-specified metal lathes, simple wood-turning and combination wood-turning and inexpensive plain-turning metal lathes, the company generally used common castings for the 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 later T.D.S.-5.B.G. were both entry-level models with the No. 4 having just belt drive and the B.G. with the addition of backgear. Lathes restricted to screwcutting by changewheels were listed variously as the T.D.S. 1/1 G.B. for inch screwcutting and T.D.S. 1/2 P.C.S. when built to an all metric specification (both these types were also equipped with power sliding and surfacing driven by a separate power shaft below and parallel to the leadscrew. Top-of-the-range models, the T.D.S.-1/1-G.B and T.D.S. 2/2-G.B. were fitted, in addition, with a full screwcutting and feeds gearbox. Some lesser models were also, of course, sold without the power cross-feed mechanism and so lacked the power shaft. An important part of the gearbox screwcutting arrangements, and vital to extend the threading range, was a set of extra changewheels, stored 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.
Changewheels on Viceroy lathes are rather confusing: it appears that all non-gearbox models had changewheels of 18 D.P. (diametrical pitch) while gearbox lathes used 16 D.P. The transposing gear to cut inch pitches on a metric machine (by far the great majority of Viceroy lathes were metric) was a joined pair of 127/135t gears with a 9/16" bore; a 54t stud gear (the output gear from the tumble-reverse), a 48t gear with a 9/16" bore to mount on the gearbox input shaft and, to cut a wider range of inch pitches between 4 and 28 t.p.i., a 52t gear. All this data - and much more including charts to shows the various lever positions on a metric box when generating inch pictures - is contained in the comprehensive manual available here. As on many lathes, the tumble-reverse gears, at 20 D.P. were of a finer pitch than the changewheels.
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 T.D.S.2/1 G.B. (and in conjunction with its single-lever-engaged backgear) eight spindle speeds 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 basics of turning, the bottom speed of  60 rpm was rather 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 Mk. 2 machines 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 robust 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. The heavy-duty tailstock is undoubtedly one of the most useful features of these lathes.
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 a 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 and screwcutting 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 cost-cutting, plastic-coated metal handles, secured by cheap spring-dowel pins was not so praiseworthy. Finally, a few years later, the very last Mk. 3 versions were to be announced, the 280 and "Synchro" models. These were an almost complete redesign with a more complete specification; each version was fitted with a manual or electrically-operated variable-speed drive of the mechanical "Ainsworth" type that used pairs of opening and closing pulleys.
Accessories for Denford Viceroy metal-turning lathes consisted of the usual 3 and 4-jaw chucks, draw-in collets sets, a spindle-nose direct-fit collet set, a toolpost grinder with an internal attachment, turning, boring and knurling tools, a 4-way toolpost, a "Kingston" quick-change toolpost by Aloris, an American-type "lantern" toolpost, a rear toolpost for parting off, English to metric transposing changewheels and the necessary mounting quadrant, thread-dial indicators, tailstock rotating centres and tailstock chucks, a tailstock-mounted 6-station turret head by Martindale, a micro-adjustable offset tailstock rotating centre by T.Bowers  & Co. (toolmakers) Ltd. for the turning of tapers, drill bit sets, Slocombe drill centre sets, drive dogs (carriers) and a selection of tool-bit holders branded "Andycraft". A useful 4-speed powered vertical milling by Emco could also be fitted, along with a rotary table and a square-form milling table with five T-slots - three in one direction and two in the other. Another useful accessory was a special Denford-designed combined taper-turning and copying attachment, this was an all-mechanical device, with the makers claiming that "...it does not have the usual working parts found in conventional taper attachments and is thus easier to set and has less frictional losses."
Viceroy machine tools were rarely advertised in other than the educational press and are still little known and appreciated even in their country of origin; consequently, the market undervalues them and, if you want a neat, strong, very compact lathe with a generous capacity at a bargain price - a Denford Viceroy might, indeed, 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

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 it 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.

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.

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.

Tumble-reverse mechanism with the usual Denford safety feature of a release pin that could only be reached when the changewheel cover, with a microswitch-operated electrical stop, was opened

An unusual version of the Mk.1 T.D.S. 1/1-G.B. with a different apron, delivered new to Shoreditch College, (now Brunel University). The front of the apron is made as a flat rectangle with a raised boss in the centre to hold a rotating handle to select the power sliding and surfacing feeds. The mechanism for the latter must have been the same as for the Mk.2 lathes.