Atlas 12-inch Wood-turning Lathes
Models 7121 and 7122
A data pack is available for this lathe consisting of the maker's Instruction and Parts Sheets and a copy of the detailed and well-illustrated 8-page Sales & Specification Catalogue E-mail for details.
Although Atlas constructed various sizes of wood-turning lathe for marketing by Sear, Roebuck as "Craftsman" products, their own range of such machines, from the early 1930s to the late 1950s, was much more limited. By 1941, and the advent of WW", wood lathes had even been displaced entirely from the Company's main catalog, and did not reappear again until 1948 when, in a dedicated Wood Lathe Sales Brochure, the new 12" x 36" Model 7121 (later the 7122) was introduced.
Heavily built (115 lb.), the lathe had all its main casting in iron to gain the mass which is so helpful in successful wood turning. The ground-finish, No. 2 Morse taper, 9/16"-bore headstock spindle ran on sealed, factory-preloaded and shimmed deep-grooved SKF ball bearings with, at first on the Model 7121, 1" x 8 t.p.i thread at both its ends (left-handed of course on the outboard, "bowl-turning" side) and later (on the Model 7121) a 1" x 10 t.p.i. The spindle carried a 4-step V pulley which, like the 10" Atlas metal lathe, had a ring of 60 indexing holes on the face of its largest pulley. The belt run over the pulley was guarded by a neat, swing-open cast-iron cover hinged from lugs cast into the rear section of the headstock. Faceplates were charged extra with several available including 9-inch and 5.25-inch combination types with radial slots (to hold and drive metal) and drilled holes for wood threaded to fit either inboard or outboard spindle; a plain 3.5-inch unit with just drilled holes for the inboard spindle and a 6-inch combination type for just the 1" x 8 t.p.i. Spindle.
Normally, for wood turning, a standard American-style 60 Hz, 1725 r.p.m. 1/2 hp (or optionally 1/3 hp) 1-phase (or 3-phase) electric motor was mounted behind the lathe and fastened directly to the bench. Considering how well specified Atlas metal lathes were (and how complete and well-integrated their drive systems), it is odd that the wood lathe was not even offered with a simple, adjustable motor-mounting plate - which would at least have allowed the belt to be slackened before changing speeds. A fixed-position "jackshaft" (countershaft) was, however, on the options' list and this retained the original direct-drive speeds of 635, 1230, 2430 and 4680 rpm while providing an additional, slower range, more suited to the turning of large-diameter bowls (and light-duty metal and plastic machining) of 197, 372, 710 and 1343 rpm. For assistance with bowl turning Atlas offered a rather unusual (for a small lathe) floor-standing rest and it is difficult to say why the flat end of the bed, which would seem to have offered an easy opportunity to design a simple and rugged bolt-on bowl-turning attachment, was not used as a mounting point. Such an accessory, as used on many other makes of lathe, would have had a much-superior range of adjustments - and been a great deal safer.
Mounted on a swivelling base and fitted with convenient, permanently-mounted handles, the standard tool holder had a T-piece a usefully long 12-inch T-rest with the option of three others: No. 5618 a right-angle for turning and facing at one setting and two shorter straight rests: No. 0-334 at 4-inches and No. 9-33 at 8-inches. While the tailstock was locked to the bed by a fixed, cam-action lever, the ruler-graduated, 21/8"-travel No. 2 Morse taper tailstock spindle was locked by a crude, direct acting bolt. Although the spindle was provided with self-eject for its centre, this meant that it could not be hollow - and so used as a handy guide for long-hole boring.