"Vereinigte Drehbank Fabriken" (VDF) was a Post-WW2 organisation designed to assist the engineering and sales effort of a group of German machine-tool manufacturers including "Heidenreich & Harbeck, Hamburg", "Boehringer" and "Wohlenberg, Hannover". The organisation created a worldwide marketing operation with their office located in Frankfurt/Main - the exported lathes appearing to have been sold using either the maker's alone, or with just a VDF label - or, sometimes, with both a maker's and a VDF badge.
The first move of the "Association" was to create a unified design of lathe, designed Einheitsdrehbank, that was built in three sizes: the E3 by Heidenreich & Harbeck in Hamburg; the E5 by Gebrüder Wohlenberg in Göppingen and the E7 by H. Wohlenberg in Hannover. Once in production, the "E" lathes were followed by the V Series, these having their centre heights raised by between 52 and 53 mm, with, later, a further increase of 60 mm to make the Type E3H - this version being intended for larger but lighter jobs as the bulk of the lathe remained unchanged.
The lathes were not of the type with just increased centres heights, each was built as a specific model with its own bed headstock and other fittings appropriate to its expected tasks. Turning diameters over the bed were E3 480 mm (19 inches); V3 520 mm (20.5 inches); E5 580 mm (23 inches); V5 680 mm (26.5 inches).
Between centres capacities on the E3 and V5 ranged from 750 mm (29.5 inches) to 4000 mm (157 inches); on the E5 and V5 from 1000 mm (39.5 inches) to 6000 mm (236 inches) and on the V6 from 1000 mm (39.5") to 7000 mm (276 inches).
Even so, the lathes were advertised in English-language publicity literature as Standard Lathes -  though this might have been a 'mistranslation' for, in comparison with an equivalent-sized-products from such as Harrison or Colchester they were anything but "standard", being quite firmly in the superior Dean, Smith & Grange class. Built from the late 1940s onwards, the lathes were first produced as relatively simple, lower-cost machines but, as the German economy gathered pace, became better finished and upgraded in specification Changes included the fitting of screwcutting and feeds gearboxes of a type similar to those already in use on the Company's S-Type lathes, these being completely enclosed and with a wider range of pitches and feed than previously.
The lathes could also be supplied as an automatic copying lathe, the UNICOP, with electronic-hydraulic control or equipped with hydraulic copying attachments for simple repetitive production work.
Like most contemporary lathes from all makers, their mass was far in excess of those built but fifteen years precisely, the aim being to allow the use of carbide-tipped tools and much more rapid metal-removal ability with deeper cuts at faster speeds the aim.
Like most contemporary lathes from all makers, their mass was far in excess of those built but fifteen years precisely, the aim being to allow the use of carbide-tipped tools with both deeper cuts at faster rates of feed.
Of the V and flat-way type (with a detachable gap piece at extra cost), the beds of the E3 and V3 were mm wide; those of the E5 and V5 500 mm and that of the V6 560 mm. All could be induction hardened at extra cost and came, as standard, fitted with guards provided at both ends of the carriage to protect the ways. To guard against chips and swarf, the carriage rack, leadscrew, feed shaft and clutch-control shaft were all located beneath the front V-way of the bed.
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Drive came from either a dynamically-balanced motor flange-mounted against the left-hand side of the headstock, or a standard motor mounted low down at the back of the headstock-end support leg - the maker claiming that the former was the more popular choice (and obviously cheaper to build). The leg-mount motor drove upwards to the input pulley by multiple V-belts and was carried on a T-slotted plate that allowed the belt tension to be adjusted. Both motors ran constantly in the same direction the drive into the headstock being by a forward-reverse multi-disc clutch that allowed easy starting stopping and reversal of the spindle (though be warned, like all such installations, putting the clutch into reverse while going forwards with a heavy job in place resulted in the eventual and expensive need to fit new reverse plates….). Rapid power feed along the bed - handy on the longer machines - was, when selected, also controlled by the clutch.
According to a customer's particular requirements, E3 and V3 lathes could be had  with motors of 7.5 to 10 h.p.; the E5 and V5 with from 10 to 15 h.p. and the V6 with 10 to 19 h.p. Engagement of the drive was by the "third-rod" system with two levers fitted to control start, reverse and stop, one pivoting from the right-hand face of the apron, the other to the right-hand side of the screwcutting gearbox. Both levers were of the "safety" type, having to be pulled out before they could be moved and obviating the change of accidental engagement.
Lubricated by a built-in oil pump with a plate-type filter, the inside of the headstock held shafts all of which ran on anti-friction bearings and gears of hardened and ground steel. The dynamically-balanced main spindle gear was of helical form and held on a tapered section of the spindle close behind the front bearings. Double-row cylindrical bearing supported the spindle's radial loads with end thrust absorbed by deep-groove ball races. As an option, for toolroom use, the front bearing could be of the plain type, this being adjustable by a spanner with an engraved scale to aid careful setting
. Headstock spindles varied according to the model, the E3 and V3 having one with a bore of 62 mm (27/16 inches); the E5 and V5 80 mm (31/8 inches) and the V6 90 mm (31/2 inches).
All models had eighteen spindle speeds arranged in the usual geometric progression, the E3, V3, E5 and V5 having a standard set from 11.2 to 560 r.p.m. and the V6 from 7.6 to 375 r.p.m. Several alternative ranges were available, the fastest of these going from 35.5 to 1800 r.p.m. on the E3 and V3; from 18 to 900 r.p.m. on the E5 and V5 and from 11.2 to 560 r.p.m on the V6. The speed required for a job could be determined from a plate fitted to the headstock that listed, as a guide, the diameter of the works and the suggested setting of the two-lever control. As an option, the lathes could be fitted with a Kienzle speed and feed pre-selector, this being designed to reduce slack time but bringing, as a cost, an element of long-term reliability.
Spindle noses were initially a VDF standard to DIN800, this being superseded by the more popular DIN 55022, this having a short taper for improved alignment and a quick-action bayonet lock that allowed must faster and easier changing of fittings.
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All models were equipped with the same design of sophisticated, dual English-metric screwcutting and feeds gearbox, the change from one range to the other being by a single knob. The box also held the gears necessary to reverse the direction of the leadscrew and to change the drive between leadscrew and power-feed shaft. Pitches and feeds were selected by a dial and engaged by a single lever, this arrangement allowing the box to be sealed and lubricated by a pump with oil delivered through pipes.
Module and diametric threads could also be cut, these being obtained by the simple transposing of the mounted changewheels. Pitches not listed on the gearbox plate could be obtained, in the usual way, with additional changewheels - the arrangement of this method being described as "coupling the leadscrew directly to the changewheels", a reference to setting the gearbox lever so as to have a straight-through feed.
For cutting fine pitches, a set of 2 ; 5 ratio gears within the headstock allowed threads with a minimum lead of 0.4 mm to be generated. To protect the drive against damage, a simple shear pin was incorporated in the drive.
Driving through a standard-fit, 12 mm pitch leadscrew - a 0.5-inch pitch was available as an option, as were high-accuracy versions - the screwcutting gearbox (on all models) was able to generate 81 inch pitches from 1/8" to 70 t.p.i.; 67 metric with a lead in mm from 0.4 to 224; 61 module threads from 0.1 to 56 and 81 diametric threads from 1/2 to 280.
Although the screwcutting range was identical across all models, as their work capacity varied, the 32 rates of sliding and surfacing feed were set appropriately, these being (per revolution of the spindle):
E3 and V3: sliding at 0.056 to 2mm (0.0022 to 0.08") and surfacing from 0.025 to 0.9mm (0.001 to 0.035")
E5 and V5: sliding at 0.071 to 2.5mm (0.0028 to 0.1") and surfacing from 0.04 to 1.4 (0.0016 to 0.055").
V6: sliding at 0.15 to 2.65mm (0.006 to 0.1) and surfacing from 0.03 to 0.95mm (0.001 to 0.037").
Doubled-walled of course with all shafts supported at each end, the apron was lubricated by a pressure pump with oil also directed to the bedways and leadscrew clasp nuts; an oil sight-glass was fitted the apron's front face. Engagement of sliding and surfacing feeds was by a single lever working through a drop worm, this mechanism allowing both an instant engage but, more importantly, instant disengage even under the heaviest of cuts. In addition, the apron held mechanisms by which means the cut could be reversed and also a useful automatic disengagement for the longitudinal feed activated by bed-mounted stops. The latter system, besides providing safety against inadvertent damage, meant that an operator, when turning a long job, could safely immerse himself in a copy of a football, motorcycle or girly magazine - surreptitiously held inside an engineering drawing…
Oddly, the 5-spoke carriage handwheel was not fitted with a micrometer dial - though one could be ordered at extra cost - and the rim was smooth, not an ideal finish on a large lathe were oil-hands might need to reach out and grip the rim to apply a little extra cut.
Cross and top slides were of ample proportions and fitted with taper gib strips and crisply-engraved micrometer dials, that on the cross-slide being usefully large in diameter. While, as part of the standard equipment, a short, plain cross-slide with a swarf guard at the rear and just a single clamp-tpe toolpost were specified, the makers offered a very wide range of options, including 4 and 6-way, quick-change and rear toolposts on a raiser bock held ; a cross-slide of extended length that carried a top-slide with two tool holders; twin cross-slides each with their own top slide; twin cross-slides each with their own power-feed top-slide - though the twin cross-slide arrangement meant that neither taper turning nor hydraulic copying could be fitted and was not available on the E3. It was also possible (sensibly only on longer-bed versions) to order a second complete carriage assembly, complete with any of the previously-mentioned optional extras.
Supplied with each new E and V lathes was a chip tray, driving plate for between-centres work, fixed steady, travelling steady. Morse centres, bed-mounted carriage stop, cross-feed stop, spindle-speed table, spanners and operating instructions.
In addition to special machines built to a customer's specific orders, the factory listed a wide range of optional extras, these including a hardened bed, bed gap piece, spindle-nose bayonet fittings to DIN 55022 and standard American-type Camlock, an increased spindle-speed range, coolant equipment with electric pump, 4-way, 6-way and quick-set toolposts, taper turning, hydraulic copying attachment, power-feed to the top slide for short taper turning, extended cross slides, twin cross slides, twin cross slides with power to the top slides, a complete second carriage assembly, taper-turning attachment with micro setting by a very fine-pitch screw,  a combined taper-turning and copying attachment on an extended cross slide, a power-boring tailstock (not on the E5 and V6) this presumably being connected to the carriage, faceplates with and without T-slots in cast-iron or steel, various 3 and 4-jaw chucks in cast-iron or steel and of standard or high accuracy, chucks with electric or pneumatic opening and closing, collet chucks, a micrometer dial with a vernier for length-travel indication on the carriage handwheel, a thread-dial indicators for inch and metric screwcutting, Ammeter, Kienzle speed and feed indicator, light unit and "special accuracy" lathes for toolroom work, but only in straight-bed versions and with up to a capacity of 59 inches between centres..

Lubricated by a built-in oil pump with a plate-type filter, the inside of the headstock held shafts all of which ran on anti-friction bearings and gears of hardened and ground steel. The dynamically-balanced main spindle gear was of helical form and held on a tapered section of the spindle close behind the front bearings