Churchill-Redman CUB Lathe
Cub Capstan Model & Capacity Chart Mk. 1 & Mk. 2 Cub
Mk. 2 Cub Headstock Mk. 2 Carriage & Changewheels
An Operator's Handbook with Spares List (as detailed sectional drawings) is available for the later versions of this lathe.
SOUGHT by the writer: sale or loan of literature for the Mk. 1 & Mk. 2 Churchill Cub
Built in England by Churchill Redman Ltd. in both Halifax (Yorkshire) and Scotswood (Tyne and Wear), the 6" x 20" (later 6.5" x 24") gap-bed Cub lathe was built (as far as evidence from date-coded catalogues and older emloyess reveals) from 1933 until the early 1960s. The Scotswood plant made a number of different centre lathes, some of which were destined for Indian Railways and purchased through the Crown Agents. Evidence of how relatively slow Cub production must have been during the 1950s comes from the fact that a single foreman Jim Kennedy, who had originally worked on the lathe in the Halifax plant, was solely responsible for assembly.
In August 1957 the name of the Company changed to "Churchill-Gear Machines Ltd." and a move was made to a new factory across the river at Blaydon-on-Tyne. Even though the title had been changed the firm continued trading under its original name and the factory signs in Halifax were not altered. Unfortunately this promising development was followed by a large-scale redundancy in early 1958 and this, together with increasingly stiff competition from Colchester and their mass-produced Student and Master models, would have signalled the end of the Cub's life. By 1960, in a desperate effort to cut production costs , the works apprentices were drafted in to build the lathe. Quite how the company evaded the wrath of the unions is unknown but, apart from final painting, the lads did all the work themselves including machining the parts. The young men were quite aware that the Company did not make any mention of this in their publicity literature - and were somewhat aggrieved (having accepted the responsibility for the job) when the universally disliked works manager was seen posing proudly by a finished machine for a publicity photograph.
Although both the registration of the original design, and patents, were applied for in the early 1930s it was not until February 3rd., 1948 (and the introduction of an almost entirely different model) that anything seems to have come of this with two Design Numbers (843,456 and 844,892) together with a Patent (597764), being granted - the latter concerning an ingenious method of selecting spindle speeds. Being compact, but having a generous capacity for its size, the lathe quickly became popular with training establishments, commercial engineering companies and the Armed Services with many examples supplied to the Royal Navy for use in submarines during WW2. As a consequence of its widespread adoption by official bodies many, still in lightly-used condition, eventually found their way onto the surplus market and are still in use today.
Four versions were produced that we shall call the Mk. 1, Mk.1a, Mk. 2 and Mk. 3: these are all very easily distinguished one from the other: the Mark 1 can be recognised by its one-piece bed and headstock with the latter of square appearance and all the control levers for speeds, threads and the selection of power feeds being straight tapered arms with acorn-shaped ends: the Mk. 1a appears to have been mechanically identical but fitted with distinctive "bent" control levers; the Mk. 2, a machine with a more rounded styling, had bolt-on headstock and was fitted with neat (if rather large and smooth-faced) full-circle "hexagonal" controls (that replaced all the levers); the Mk. 3 employed just two headstock-mounted rotary controls and three octagonal knobs on the gearbox.
On its introduction the Cub's closest direct competitors were probably the geared-head 41/2-inch Denham Junior and (rather old-fashioned) 5-inch flat-belt drive Colchester Bantam. It managed to outclass both of them by offering a centre height of 6-inches, 24 or 36 inches between centres, the ability to swing a piece of material 16 inches in diameter by 4-inches thick in the gap and a useful speed range (powered by a 3/4 h.p. 1500 r.p.m motor bolted to the back of the bed) of: 25, 44.5, 81, 142, 250 and 457 r.p.m. As an alternative, and achieved by a more powerful motor and a change of pulleys, the speeds could be arranged to run from 50 to a more useful top peed of 900 r.p.m. Drive to the all-geared headstock was by twin (and then still novel) V-belts - thought at the time these were commonly referred to as "tex ropes" - with speed changes by the juxtaposition of two levers on the front face of the headstock. Much play was made by Churchill of the lathe's material specifications and heavy build, the inverted V-way bed and headstock were cast as one and, although strictly speaking the bed was not hardened, the cast iron (with the advertising puff of being described as "semi-steel") was to Brinell 200. While the two headstock layshafts with their nickel-chrome, 65-ton tensile steel gears rotated on ball races the 9/16" bore main spindle was fitted with Timken taper roller bearings set up to absorb both radial and thrust loads. The gears ran in a simple splash oil bath (with a rather venerable vertical glass oil-level indicator on the front of the headstock) with the headstock cover, and guards over the changewheels and motor-to headstock drive belt, in cast aluminium. Before dispatch from the works each Cub was run-in and the spindle bearings adjusted to eliminate the need for adjustment for: "a number of years".
Drive to the (oil-bath) three-speed screwcutting and feeds gearbox was by a train of conventional changewheels; however, instead of the expected externally-mounted tumbler to reverse the leadscrew and feed shaft an internal gear mechanism was neatly built (like a larger lathe) into the headstock where the fast-running gears benefited from a constant supply of lubricant. The leadscrew was used only for screwcutting (a lever was provided to disengage it from the feedbox) with the sliding and surfacing feeds being driven by a separate power shaft; the double-walled, oil-bath apron mounted a central push-pull button to select the feed (along the bed or across) and a screw-in handwheel to engage the drive through a cone-type friction clutch. On the Mk. 2 lathe the selector lever was changed to a flick-left-and-right type, but the cone clutch remained. The right-hand face of the apron was fitted as standard with a thread-dial indicator but, instead of a sight-glass that showed the state of the oil level at a glance, a simple flip-top oil cup was supplied that required the operator to open, check and top up as necessary.
Fitted with taper gib strips the compound slide rest was equipped with decent "balanced" handwheels and what were, for the time, good-sized micrometer dials. Unfortunately the cross slide was of the short type, but at least with a stout, cast-iron cover at the back to protect the end of the feed-screw from the wearing effects of swarf and dirt.
Early versions of the lathe have been found mounted on a pair of heavy-gauge, pressed-steel, all-welded legs complete with a chip tray while later variants were also available on "semi-cabinets" with a welded sheet-steel box structure at the headstock end of the bed and a simple leg, in cast iron or pressed steel, at the other.
Although a sound lathe, by the end of World War Two the Cub was looking decidedly old-fashioned and, to address the situation, Churchill embarked on a complete redesign. The resulting Mk. 3 was not only more modern and powerful-looking but also incorporated numerous mechanical improvements that allowed the lathe nearly another 20 years of life. The new model was not only well engineered but of especially heavy construction, weighing some 1232 lbs (559 kg) - as much as a Colchester Student - yet it was very compact and needed a floor space of only 5 by 2 feet. By the standards of the 1940s it had an excellent basic specification and was delivered mounted on a neat, all-welded cabinet base. The stand housed the motor, its control gear and had built-in coolant equipment; the centre portion contained the electrical switchgear (and sometimes a drawer) while the right-hand side had two drawers (one of which could be locked to hold the operator's personal belongings) and a cupboard. The headstock, designed to absorb the rigors of industrial use, had an oil-splash lubricated, all-geared taper-roller bearing spindle controlled by a combined spindle clutch and brake. Sliding and surfacing feeds were driven by a separate 5/8" diameter feed shaft working through an oil-bath apron. A removable gap in the bed allowed material 17.5 inches in diameter and 4.375 inches thick to be turned while a sealed, oil-immersed screw-cutting gearbox was fitted as standard. By the late 1940s versions were being offered with the option of a more modern-looking, neatly-constructed fabricated-steel cabinet stand with the left-hand side containing the motor. The original finish - at least of the later models - appears to have been a rather dark shade of the standard "British machine-tool grey".
The same reasons that made the lathe appeal to sub-mariners should also attract the home-user today: a rugged build, generous centre height with an enormous capacity in the gap, a reasonable between-centres distance, versatile performance, compact dimensions, a capacity to endure serious rates of metal removal - and all at a price well below that asked for other modern machines of a similar size (if better specification) - the Colchester Bantam and Harrison M250, for example. Of particular interest to the amateur, who may have to transport his own machine and then install it in an inconveniently-sited workshop, is the ease with which all but the Mk. 1 Cub can be dismantled into its component parts; competent mechanics have been known to remove the tailstock, carriage, gearbox and headstock in about 15 minutes leaving a naked bed attached to a now easily-moved cabinet; the same job on Bantam or M250 will take the best part of an entire morning.