Designed and developed during the 1950s by Mr. Sakai, owner of the Japanese Sakai Special Camera Mfg. Co. Ltd., the original Toyo was not intended  as a commercial proposition, but to help with production of his large-format box cameras. However, so successful did the lathe prove (and, with so few machine tools of the type available in Japan at the time) it found a ready home market followed by strong overseas sales - where the competitive price undercut machines of similar quality from Germany (for example, Lorch and Boley Leinen)  and America (Levin and Derbyshire).
Of delightfully simple construction, yet cleverly-engineered, the precision ML1 was 590 mm long, 260 mm wide, 175 mm high and weighed around 15 kg. With a 50 mm centre height and a capacity between centres of 250 mm the lathe was ideal for watch, clock and instrument work and was unusual for its time in having (like the late-model Boley F1 lathes of a similar size) a tightly integrated drive system. Whilst the Boley was based on established watchmaker's design, and fitted with specialist equipment for turning and boring pivots, Toyo used a drive system very similar to that on the 1954 Emco "Unimat" with a rear-mounted 100/240V 50/60 HZ 145W motor (with neat, built-in switch gear) set to drive the spindle directly or via a speed-reducing intermediate pulley. The result was a range consisting of a single slow speed of 250 r.p.m. and three high of 1000, 2000 and 3000 r.p.m.. Running on precision ball races the hardened and ground spindle was bored through to clear 12 mm and carried an unusual  size of Morse taper in the nose - a 1.5. The spindle end was formed not with a thread, but a blank end, tapped to take chucks and other fittings secured by bolts passing through their bodies. This arrangement provided perfect precision and security when run in reverse, but meant a time-consuming job to change fittings. For holding collets a simple type of compression collet holder was offered (with a screw-on nose) that took standard dead-length collets in metric-only sizes with bores of : 2, 2.5, 3, 4, 5, 6, 8 and 10 mm.
Most interesting was the arrangement of the bed and carriage assembly: the bed, carried on a cast-iron under-plate, was formed with "vertical" square-section ways on both the front and rear faces and supported a carriage with an apron both at the front and rear - a design that was, for its size, unique. As confirmation of the suitability of this arrangement the superb, hand-built Rolls-Royce precision lathe of 1948 used an almost identical arrangement. Because the headstock could be rotated on the bed, only a two T-slot cross slide was fitted - there being, at first, no offer of a top slide unit. However, with the advent of the ML210 the slide from this was offered as an option under Part Number 3017. Although the cross slide travel, at 65 mm, was very reasonable, the makers neglected use the old trick of increasing this (and thus making it more useful when a milling slide was fitted) by the simple expedient of using a cantilevered feed-screw support bracket instead of the simple flat-plate type fitted.
Unlike most contemporary precision lathes of its size and type (which tended to use just a simple, bolt-on compound slide assembly) the ML1 was able to drive its saddle along the bed. Not only could this be done with a graduated handwheel at the tailstock end of the bed (the travel was 250 mm) but also under power, through a train of gears connected to a leadscrew that ran down the centre line of the bed. However, in this respect it was not alone, the tiny American ManSon hobby lathe of the 1940s managed the same feat on an even smaller scale. With the leadscrew passing down the centre of the bed the carriage attachment point was arranged to be directly under the toolpost, so ensuring as near a straight-line pull as possible - rather in the manner of, amongst others, the toolroom-class Boley L Series lathes
Available as an optional-extra, the changewheel set was mounted inside an enclosure carried by the outer face of the leadscrew's dog-clutch assembly. Although the gear were able to generate a useful range of pitches - 0.25, 0.3, 0.35, 0.4, 0.5, 0.6, 0.7, 0.75, 0,8, 0.9, 1.0, 1.25 and 1.5 mm - the relatively high bottom speed of 250 r.p.m. would have made screwcutting rather an awkward proposition. However, in mitigation, it must be said that the surface finish of the very small diameter threads likely to be generated would have benefited from such revolutions. The gears could also be arranged in various compound settings to give different rates of fine sliding feed and their housing ensured that no lubricant was splashed onto the drive belts or contaminating the operator's hands as he changed speeds.
Of conventional design - but with guidance ways at both front and rear - the No. 1 Morse taper tailstock had a 38-mm travel barrel with its handwheel engraved (or most likely rolled) with a micrometer scale.
Over a long production run only minor changes were made to the ML1, one of which was the use of parallel instead of taper-face micrometer dials and the application to them of a chrome rather than natural finish. Another version of the ML1 was also made, the ML2. Fitted with a 250 mm diameter faceplate, and having three speeds of 100, 300 and 500 r.p.m., this was intended for large-diameter facing work but sales must have been few and the model is rare - most clock, watch and instrument makers already having larger lathes in their workshop.
Despite being a genuine precision lathe, with a number of advanced and ingenious features, models of all years  were finished in an unfortunate choice of paint - a cheap-looking green "Hammerite" - that would have been more at home coating one of the early, casually-assembled and badly-made Taiwanese lathes made for the amateur market in the early 1970s.
A friend of the writer's bought a new ML1 in the early 1970s and, after changing the micrometer dials for a set of larger, finely-engraved and chemically blackened units, spent many years turning out tiny experimental jobs under sub-contract for Rolls Royce..