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Churchill-Redman "Cub" Mk. 3 as supplied during the late 1940s and 1950s. The cam-action lever on the face of the apron engaged and disengaged the power feeds and was a considerable improvement on the slow-to operate screw-in-and-out knob used on earlier versions. Continued: Hand scraped until it was a perfect fit on the bed the separate headstock carried a 3/4" bore spindle supported in a pair of opposed Timken taper-roller bearings at the front and a roller bearing at the rear. The spindle nose appears to have been Churchill's own adaptation of the standard "Camlock" flange - but with 3/8" Allen screws instead of studs - and carried a No 3 Morse taper; Pratt Burnerd apparently retain a pattern of the Churchill mount and are able to supply new chucks with the proper fitting built in. All the gears had shaved teeth and were hobbed from nickel-chrome, heated-treated steel with the speed changes made by a single rotary control conveniently sited on the front face of the headstock. The other headstock shafts (as they had on the Mk. 1 and Mk. 2) revolved in ball races. The standard drive system consisted of an under-slung 2-speed, 3-phase motor mounted on an adjustable plate (to allow for belt tensioning) that ran at 960 and 1400 rpm and drove to the geared-headstock input pulley by two M-section V belts to give 12 spindle speeds in a range that, whilst it varied over the years, was typically 45 to 900 rpm on very early machines with some (probably those ordered for use in training establishments) with a much lower top speed of 400 rpm. Later machines were given a somewhat improved range (although the top speed was still a little slow) of: low-range 32, 60, 112, 190, 356 and 665 rpm and high-range 48, 90, 168, 285, 534 and 1000 rpm. In today's faster world, if the owner's work demands a higher top speed then it is unlikely that the roller-bearing headstock would protest (although the motor might) if the top speed were lifted to some 1500 rpm or so by using a larger pulley on the motor shaft. Not all machines however were fitted with the two-speed motor as both single-speed AC and DC units were available as options, the former likely to have been specified when used in a training role. When fitted with a single-speed motor 6 speeds were available with a choice of two ranges, either 48 to 1000 rpm or 32 to 665 rpm. The headstock input pulley incorporated a multi-plate disc clutch the design of which was improved in 1948 from machine number 16048 Ground-finished from a substantial and heavily cross-braced casting the massive bed carried double-Vee slideways, one for the saddle and one for the tailstock, and was fastened to its cabinet by four 3/8 Whitworth setscrews - but not shimmed or levelled in any way; a simple plain cardboard gasket was used to seal against coolant leaks into the cabinet whilst the detachable gap bridge was secured by four Allen screws. The compound slide rest was fitted with proper taper-gib strips and large, zeroing micrometer dials. The top slide could be swivelled through 360 degrees and a steel 4-way tool post was mounted as standard. The apron was of double-walled construction with an oil bath in the base with all the shafts, supported at each end, running in easily-replaced bronze bushes. Whilst the sliding and surfacing feeds were still selected by the same lever arrangement from the Mk. 2 (that was flicked left and right from its central, neutral position) they were now engaged and disengaged by a quick-action toggle lever whose action allowed the drive to be instantly released - a considerable improvement over previous slow-to-operate wind-in-and-out knob. The power feeds were also arranged to work through a spring-loaded safety clutch built into the drive shaft just before it entered the feed box; as before a thread-dial indicator was fitted as standard. Screwcutting was taken care of by a 4 t.p.i. 7/8" in diameter leadscrew driven from an enclosed, splash-lubricated gearbox operated by two dials and capable of generating 30 pitches from 10 to 76 t.p.i. and 30 sliding feeds from 0.001" to 0.0076" per revolution of the spindle. Whilst the sales literature claimed that additional changewheels of 30t, 60t, 60t, 110t and 120t were provided with each machine to extend the threading range from 2.5 to 75 t.p.i. (and the feeds from 0.001" to 0.030") an examination of machines in use appear to indicate that the original gear train (for a gearbox-equipped lathe) used a 30t drive gear, 110t idle gear and a 120t gear on the gearbox input shaft. Stored outboard of the idler gear and gearbox input shaft were gears of 45t and 50t - but with no sign of the 60t gear. At extra cost an additional nine (unspecified) changewheels were available to generate metric pitches from 0.20 to 8.0 mm pitch. The surfacing feeds were set at the usefully fine rate of one-fifth those of the sliding. Although the structure of the tailstock was entirely ordinary, the method employed to lock it to the bed was not: a handle (conveniently positioned at the top of the casting) was rotated in a horizontal plane and, through a captive nut, drove a system of levers that pivoted inside the tailstock body and drew up a locking plate firmly against the underside of the ways. Conventional parts of the tailstock included the set-over base, locked with two screws and the No. 3 Morse-taper barrel, fed by a screw and handwheel, with a travel of 3 inches, and self-eject for the centre. Coolant was distributed from a gear pump attached to the rear of the bed below the headstock and driven by a V-belt from the rear of the headstock spindle. Cutting fluid was taken from a small tank in the cabinet and fed along a pipe inside the bed to an outlet union part way along it. One interesting addition to the usual accessories (a taper-turning unit, large faceplates, collets and fixed and travelling steadies) was a 6-station self-indexing capstan slide attachment (with 6 inches of tool travel) that fitted in place of the tailstock yet left the standard carriage undisturbed. Once very popular this fitting allowed a small machine shop to gear up for short productions runs without having to find the space and money for a (at the time hard-to-find) small capstan lathe. Unusually, instead of being just bolted to the bed - as were the vast majority of similar capstan heads offered by competing companies - this was a fully powered version, driven from the feed shaft, that turned the lathe into a unit capable of serious work. Charles Churchill and Churchill Redman made (and also marketed in collaboration with other manufacturers) a wide variety of other machine tools including toolroom, automatic, heavy-duty, centre, hydraulic-profiling, surfacing and boring lathes; shaping machines, Churchill-Cleveland hobbing machines and Churchill-Red Ring gear shavers. If any reader can provide photographs, advertising catalogues or other literature and information relating to the very early models of the Cub, the author would be pleased to hear from you..
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