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Sold during from the late 1950s onwards, the Sajo VF vertical milling machine appears to have been built as a single model and manufactured until the early 1970s. For economy of manufacture, it used the same table, saddle and knee assembly as the Mk. 2 Model 54 Plain Horizontal (but with a slight change to the rates of power feeds) and with the main column formed as a vertical machine.
Heavily built, the main column casting was formed as one piece with a heavy foot that doubled as a coolant tank. Inside the foot, ribbing increased its rigidity and was utilised as swarf settling traps. A door on the right-hand side of the column gave access to the electrical system (with a plug provided for an extra-cost light unit) with, at the back of the column, a hinged door to cover the 7.5 h.p. or optional 5 h.p. motor, both of which drove, using six V-belts, direct to the spindle speed-change gearbox. With the motor mounted on an adjustable plate, to adjust the belt tension, an external handwheel was provided at the bottom of the column's left-hand face.
Following the example of Cincinnati mailers dating from the late 1930s, control of spindle speeds was by a large dial set on the left-hand face of the column; one movement of the crank handle fitted to the dial selected the next higher or lower spindle speed - of which sixteen reversible ones were available that spanned either 39 to 1500 r.p.m. or, optionally, 31 to 1200 r.p.m. - all identical to those used on the Horizontal models. Electrical control of the miller's spindle drive was by a triple-function lever - mounted on the left towards the top of the column - that gave a start, stop and brake function, the latter by applying gentle pressure in the stop position.
Able to be swivelled 45° each side of vertical, the vertical head held a spindle identical in its construction to that of the horizontal model; it held in a handwheel-controlled quill with a travel of 80 mm and had a No. 50 INT nose that was hardened inside and out. Machined from a chrome-nickel steel forging it ran, of course, in a high-class grade of Swedish-made SKF bearings with, at the nose, a staggered, double-row cylindrical roller was to take radial loads, two ball thrust bearings immediately behind it to absorb axial thrust and, at the top a single cylindrical bearing. Fitted with provision for adjustment, the bearings were all of the "SP" -special precision - type. Inside the main column, the speed-change gears were all in the very best grade of "Bofors" alloy steels and hardened and ground (or shaved) for their particular function. All the gear-carrying shafts ran in SKF anti-friction bearings with lubrication a pressure pump.
Heavily built as a box-section casting, the knee was internally ribbed for extra strength and housed, flanged mounted to the left-hand face, a 1.5 h.p. table-feed motor, Built into the knee was a feed-rate-change gearbox with lubrication by splash from a sump. Long, hand-scraped ways were used with tapered gib strips to take up play and, to protect against the ingress of swarf and dirt, the top of the knee was fitted with telescopic metal plates - and the knee and column bearing surfaces covered by fabric aprons.
1320 mm long by 280 mm wide, the table carried three 18 mm T-slots spaced 70 mm apart and all-around coolant troughs. Fitted with a single handwheel at its left-hand end - and a large-diameter, satin-chrome plated micrometer dial - the table's longitudinal feed screw ran through a two-part, bronze nut that was adjustable from a screw on the face of the saddle. This provision aimed to make available an immediate elimination of backlash - and so help with climb milling. Under power, travel longitudinally was 850 mm, in traverse 300 mm and vertically 455 mm. Twelve rates of table and knee feed were available for each of the three directions, these ranging from 15 to 530 mm per minute longitudinally and in traverse and at half that rate vertically - the rate required being selected by a capstan handwheel on the frnt of the knee. Each feed was operated by a separate lever, the direction of travel being the same as that of the lever. Rapid feeds were available in all three directions, at 3000 mm per minute longitudinally and in traverse and at half that rate vertically, the usual type of control for this being provided by a long, spring-loaded lever pivoting from the right-hand side of the knee that, when released, stopped the travel.
Lubrication of the table ways and drive mechanism was by a one-shot system, the plunger for which was placed clearly in view on the front of the saddle. Coolant equipment was part of the standard specification, the geared pump being driven by a V-belt from the main motor.
Standing 1982 mm high, 1771 mm across the full extent of the table and its handwheel and 1606 mm from front to back, the Sajo Model VF54 weighed approximately 2100 kg.
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