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Manufactured in Denmark during the 1940s and 1950s, Hero milling machines were little known outside their native country. Several versions were offered, of which just two horizontal types appear to have been exported to the United Kingdom: the 4U Universal with a swing table and the 4P Plain. Tested on completion to Schlesinger standards, both were of identical construction - apart from the swing table of course - with the main column and foot formed as one section in cast iron with, machined into the front, an unusually wide V-edged way to carry the robustly built knee. Power came from a rear-mounted, 2-speed, 2/2.5 h.p. 1400/ 1700 r.p.m motor driving by V-belt running over 2-step pulleys to an intermediate shaft and from there by a flat leather belt a 3-step cone pulley on the spindle - the arrangement giving 12 speeds from 53 to 1250 r.p.m. The six faster speeds were direct by belt and the slower 6 through a lathe-like backgear assembly with helical teeth held on shafts running in ball races - a single lever on the right-hand face being used to select the desired drive. The system, according to one satisfied user, gave an impressively smooth and quiet drive.
Made from case-hardened, nickel-chrome steel, the main spindle had a No. 3 Morse taper socket in its nose as well as an external taper that allowed for the fitting of cutter heads to an unspecified DIN standard. The front bearing consisted of two SKF taper rollers (that also took end thrust) with a simple cylindrical SKF at the rear. Supplied as part of the standard equipment was either a 1-inch or 22 mm diameter cutter arbor in a tempered nickel-chrome steel with case-hardened and ground collars - however, as an option, full-length or stub arbors in other diameters, Imperial or metric, could be provided. Betraying its age - possibly this was a pre-WW2 design - the overarm was a round bar clamped in place by two bolts closing down slots in the casting.
Fitted with three 14 mm T-slots on a spacing of 62 mm, the 750 x 230 mm (29.5" x 9") table ran on hand-scraped, V-edged ways equipped with tapered gib strips and had 19.6875" (500 mm) of longitudinal travel using hand feed and 19.3125" (490 mm) under power. Cross travel (by hand only) was 175 mm (6.9") and vertically 365 mm (14.4"). Table feed screws were of Acme form and turned by "balanced" handwheels - these being fitted to both ends of the longitudinal feed screw. Where the screws passed through their substantial end plates SKF thrust bearings were fitted to improve the operator's "feel". Crisply engraved and fitted with a ring of knurling for oily hands to grip, the micrometer dials (engraved in intervals of 0.001" or 0.1 mm) were relatively small (though in line with contemporary practice), with the one at the left-hand end of the table being much reduced in diameter compared with that on the right.
Six rates of power feed were provided, from 0.66 to 8 inches (13 to 160 mm) per minute with micrometer-dial equipped trip dogs provided for knock-off in each direction, Both the hand-driven vertical and traverse feeds also had travel-limit stops, fitted with the same type of adjustable contact screw.
Drive to the table came from a 2-lever gearbox bolted to the left-hand face of the main column; the box did not have its own motor but, like the majority of similar machines from the English maker Tom Senior, was connected to the main spindle drive by a V-belt and transmitted power to the table through the usual sort of universally-jointed, sliding carden shaft to a worm box beneath the feed screw.
While the table and knee used ways with the expected V-edged faces, the saddle ran on ones formed with surfaces set at right angles to each other, the span being generously wide and the design being similar to that employed on other high-quality machines such as the Hayes Diemaster (though that had a V-way on the outside) the makers claiming that the design reduced the tendency of the saddle to tilt under extreme loads. Gib strips on longitudinal and cross ways were of the taper type, that for the vertical a thick gib block adjusted by pusher screws.
Supplied with each new machine was a single cutter arbor, a motor pulley (but not the motor or its associated switchgear), a double-acting suds pump driven by belt from an extension to the main drive and complete with all fittings, a grease gun, a complete set of spanners, an instruction book and a test chart.
Amongst the expected range of extras offered were a simple non-quill-feed swivelling vertical head, Type VF4, with a No. 3 Morse taper nose and 12 speeds from 61 to 1450 r.p.m.; a slotting head, Type S80, with a maximum stroke of 3.125" (80 mm) and a 3/4" (20 mm) bore toolholder; a 4" (100 mm) high, 9.75" (250 mm) diameter rotary table, Type R250, with dividing plate; a swivel-base machine vice, Type SK120, with 4.75" (120 mm) wide jaws that admitted work 4" (100 mm) deep; a simple 24-hole indexing head for direct division, Type 4D125, mounted on an angle plate that allowed for either horizontally or vertical mounting; a universal dividing head, Type 4U125, with a set of 12 changewheels that made it possible to obtain all divisions up to 400 and spirals with pitches ranging from 0.02" to 80" (0.5 to 2000 mm) to be milled; a plain diving head with tailstock, Type 4P125, with a centre height of 4.875" (125 mm) and with 10.75" (275 mm) between centres and able to make all divisions up to 58 and more beyond that figure; a special index plate was also available that gave divisions of 2, 3, 4, 6, 8, 12 and 24 without use of the worm wheel..
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