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Cataract machine tools had their origins in two companies: the Cataract Tool and Bicycle Company (named after the waterfalls visible from the factory grounds) and the Cataract Tool and Optical Company the latter being incorporated in Buffalo (New York). In order to acquire rights to the company's rifle scopes the enterprise was bought out in 1902 by the well-known gun and tool maker J.Stevens Arms & Tool Company, of Chicopee Falls, Massachusetts. Stevens, who employed the skills of former Cataract manager Mr. F. L. Smith, continued to market the scopes under their original name but (after an unknown lapse of time) passed the machine-tool side of the business on to Hardinge Brothers.
The addition of the Cataract range enabled Hardinge to expand considerably, though only into what must be regarded as a niche market for, apart from a precision backgeared and screwcutting toolroom lathe (made from approximately 1912 to 1925), a limited range of milling machines and their famous range of collets, Hardinge concentrated on very high quality watchmakers' and toolmakers' lathes. The latter were by far the most important and profitable machines and were beautifully constructed and finished: they were evolved steadily improved through three distinct models - all with the same bed and each being an improvement on its immediate predecessor - yet with the earlier version always remaining in the catalogue alongside the newer. Although the term "Bench Lathe" no longer implies a very-high quality, precision tool when these lathes were at the height of their popularity, before WW2, that was the expression often used to designate this class of machine.
The bed, supported on round feet that were to become a trade mark of the brand, was almost exactly similar in section to that used on many watchmaker's lathes with, at first, a largely round-section casting flattened on top and with bevelled edges to locate the headstock, compound slide and tailstock. Later models had a bed of modified section that was stiffened by the addition of a long rectangular section along the underside - a feature visible in the picture immediately below. A slot was cut vertically through the bed to allow the compound slide rest (or other components) to be repositioned and secured with the usual sort of capstan-handwheels bearing against a flat machined along the underside of the bed. Whilst the compound slide rest was held against the bottom of the bed the headstock, tailstock and various accessories were secured in place by a T slot cut into the top surface. A distinctive tool tray was used for many years on the earlier models and secured in front of the headstock by two screws.
The headstock casting was of the finest grade, seasoned and heat-treated alloy cast-iron hand scraped to fit the lathe bed; early machines followed the traditional design for this type of lathe with the smallest of the three headstock pulleys being positioned to the right, so allowing the all-important front headstock bearings to not only be made larger but also (because the smaller pulley left a greater clearance) surrounded by as great a mass of supporting material as possible - however, in the case of earlier Cataract models it is obvious that not full advantage was taken of this design point The headstock spindle, made from ball-bearing steel, was hardened and ground both internally and externally and ran in hardened plain bearings - this arrangement was the very best that the technology of the day could provide - and one that stood the test of time, with many lathes clocking up tens of thousands of hours of arduous service at high rpm without the spindle and bearings showing any signs of wear. The spindle nose carried a patented Hardinge quick-action taper fitting (that was to be used on all their lathes until modern times) although, if the customer preferred, an ordinary thread could be supplied instead. To assist with chuck and faceplate removal the outside flange of the largest belt pulley was provided with four holes that could be engaged by a substantial pin at the rear of the headstock; the same pulley face also carried a ring of 60 indexing holes.
Later lathes adopted an even more rigid headstock with the spindle running on specially-made, high-precision, pre-loaded ball-bearing races; the makers rightly claimed that with this improved arrangement not only could speeds be higher for a given size of motor, but under heavy cuts the spindle was less likely to deflect and loose its accuracy - and so critical jobs could be completed in less time. On still later machines the headstock was completely enclosed (a design that had been used for some years on larger Hardinge lathes) and the belt changed from a flat to a twin, or triple, V; whilst the V-belts were claimed to be an advantage in terms of grip under high loads, when the maintenance fitters arrived to fit new ones they would not have been best pleased when faced with an extensive amount of dismantling work - followed by even more careful reassembly and the checking of bearing clearances, pre-loads and belt run alignments.
The makers had an interesting point to make about the headstock ball bearings; they explained that the loads on a plain bearing were supported by a film of oil: "…. the success of which depends upon such variable factors as the film thickness, the temperature and difference in the grades of oil used. With a pre-loaded ball bearing the pressure between balls and races is such as to prevent formation of an oil film and the contact of load carrying members is positively metal-to-metal. In other words the load is carried on perfect spheres of hardened steel instead of globules of oil whose load-carrying ability varies with the operating temperature. Naturally, accuracy with speed and long life is attained." This is an interesting point - but, have you ever tried stripping the lubricant from inside a ball race out with degreaser, and then seeing how long it lasts under a heavy load ? It is hardly an experiment one needs to conduct .
A detailed picture of the headstock ball-bearings, and the method of adjusting them, can be found here..
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