email: tony@lathes.co.uk
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Sajo Milling Machines Models 53 & UF44
Sajo Model 54   Sajo VF54 Vertical   Sajo UF48, UF48P, PF49P

Sajo Manuals and catalogues available here


Sajo milling machines were manufactured by Sandéns Mekaniskaa Verkstad in Värnamo, Sweden. Sold during the 1950s, the Model 53 was built around a substantial column casting formed as one piece with a heavy foot that doubled as a coolant tank. Inside the foot, ribbing increased its rigidity and was utilised for settling traps. A door on the right-hand side of the column gave access to the electrical system (with a plug provided for a light unit) with, at the back of the column, a hinged door to cover the 3 h.p.motor and its three V-belts that drove direct to the speed-change gearbox. Mounted on an adjustable plate, the motor could be adjusted up and down by an external handwheel should the belt tension need altering.
The Sajo 53 was offered in both Plain Horizontal and "Universal" types, the latter having a table that could be swing on its vertical axis by up to 45° on each side of central. 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. Electrical control of the miller's spindle drive was by a triple-function lever - mounted on the left of the column and adjustable for position - that gave a start, stop and brake function, the latter by applying gentle pressure in the stop position.
Fitted with a No. 50 INT nose that was hardened inside and out, the spindle was machined from a chrome-nickel steel forging and ran, of course, in a high-class grade of Swedish-made SKF bearings. At the spindle nose a staggered, double-row cylindrical roller was used to take radial loads with two ball thrust bearings immediately behind it to absorb axial thrust. At the other end of the spindle, a single cylindrical bearing was used. 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 by a pumped supply of oil.
One inch (25 mm) in diameter, the cutter-holding arbor was a precision ground forging of nickel-chrome steel and carried a set of lapped spacers; it was supported at its outer end in a single drop arm fitted with an adjustable bronze bush. The overarm was of the dovetail type, taller in the centre than at the ends, and was cored from one end only to provide an unbroken and hence twist-resistant tubular section; its slides were precision ground to fit into the hand-scraped slides on top of the main column turret. It is believed that later versions of the miller had an overarm that was almost the same depth front to back.
Heavily built, the table knee and saddle assembly had long, hand-scraped ways with tapered gib strips to take up play. 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.

1050 mm long and 235 mm wide, the table carried three 18 mm T-slots spaced 57 mm apart and all-around coolant channels. Fitted with a large, satin-chrome plated micrometer dial, the table's large-diameter longitudinal feed screw ran through an adjustable two-part, bronze nut the setting of which was controlled by a screw on the face of the saddle. The aim of this provision was to make available an immediate elimination of backlash - and so help with climb milling. Just one handwheel was fitted to the screw, at its left-hand end. Travel longitudinally under power was 700 mm on the Universal model and 625 mm on the Plain. Power cross feed on both types was 190 mm, though could be increased to 210 mm using hand control. Vertical travel under power was 440 mm - and by hand 450 mm. Although advertised as having power feeds in all directions, a cheaper model was offered with power longitudinal feed only, this having the advantage of increasing the clearance from the top of the table to the centre line of the spindle from 450 to 480 mm. Twelve rates of table and knee feed were available, these ranging from 15 to 530 mm per minute longitudinally and in traverse and at half that rate vertically. Final drive to the table's feed screw was by a worm gear with a hardened and ground steel screw and a centrifugally cast phosphor bronze worm wheel. As on all drives of this type, the drop-out worm allow the disengagement of feeds no matter how heavy the cut applied.  On the Plain model only, rapids were fitted to the tables longitudinal feed .
Built into the right-hand side of the column, the feeds' gearbox was driven by an oil-immersed chain from the main spindle and transmitted its drive through two universally-joined and splined shafts to the table and knee. Gears inside the box were all machined from hardened chrome-nickel steel hand had been run in for quiet operation. Shafts ran in anti-friction SKF bearings with a clutch provided to prevent damage from overloading. Lubrication was by an oil bath fitted, like the oil bath inside the apron, with a sight-glass level indicator and the table and knee ways fed from an oil gun.
Coolant equipment was part of the standard specification, the geared pump being driven by a V-belt from the main motor.
A range of accessories was available including a changewheel-driven dividing attachment for the Universal Model, rotary tables, a slotting attachment, machine vices and two vertical heads - one a swivelling type mounted on the horizontal spindle flange, the other carried on a horizontal shaft support by the drop bracket.
Standing 1620 mm high, 1540 mm across the full extent of the table and its handwheel and 1227 mm from front to back, the Sajo Model 53 weighed approximately 1260 kg.



Teknisk beskrivning och specifikation på svenska nedan
A simpler machine than the  Model 53, the Type UF-44 had a table of almost exactly the same size but with greater travels. Measuring 1050 x 236 mm, the table had three 18 mm T-slots spaced 58 apart and had, inboard of the surrounding coolant trough, a clamping area of 860 x 175 mm. Longitudinal travel using power feed was 750 mm, in traverse by hand of 210 mm and vertically, also by hand only, of 490 mm. Twelve rates of power longitudinal power were provided ranging from 0.06 mm to 1.99 mm/min. As the table power feed gearbox was driven by a belt from the main spindle, the number of spindle speeds was also twelve, these being 36, 56, 86, 100, 155, 228, 245, 350, 535, 625, 960 and 1540 r.p.m. Fitted with a No. 4 Morse taper nose, the spindle ran in SKF anti-friction bearings.




Sajo Manuals and catalogues available here

Sajo Model 54   Sajo VF54 Vertical   Sajo UF48, UF48P, PF49P

email: tony@lathes.co.uk
Home   Machine Tool Archive   Machine-tools Sale & Wanted
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Sajo Milling Machines Models 53 & UF44
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