A design dating from the mid 1930, the 102 mm x 450 mm (4" x 17.75") Schaublin 102-VM lathe is the most frequently encountered of the company's smaller screwcutting models. Of ingenious (if complex) execution, it was built from high-quality materials and became a worldwide favourite in toolrooms and precision workshops. Today, although the original 102-VM lacks the extra capacity and the user-friendly features found in precision lathes of later design (such as the Monarch 10EE and especially the Hardinge HLV), it remains very sought-after, always commands a high price and, if looked after, can be regarded as a sound investment. An unusually wide range of (expensive) accessories was available that allowed the lathe to perform numerous precision machining, milling and grinding operations.
As standard, the original 102-VM lathe was fitted to a compact but massively heavy (274 kg/604 lb) cast-iron one-piece stand and chip tray with either one or two centrally positioned lockable storage drawers. Available in several configurations to suit toolroom or production work, it was normally supplied with the motor mounted on a hinged bracket that could be lifted by a foot pedal to ease speed changes together with a quick-action belt shifter (part No. 102 VM-80.200) and a strange (but effective) knee-operated start, stop and reversing switch (No. 102-80.300). Operation of the speed-change mechanism took a little practice to master - the technique being to use both it and the motor-lift pedal simultaneously.
With large, integral feet at each end the bed was similar to that used on the plain-turning 102 lathes but with carriage ways formed as extensions to the bed's front and back walls (covered with screw-on sheet metal covers) - the front of V-form and the rear rectangular. As a full-length central T-slot ran down the middle - and traditional bevelled sides were employed - the bed could also mount many of the plain lathe's accessories.
Available with a choice of headstock spindles, the one fitted as standard (Part No. 102 VM-27) had a 20-mm bore and a maximum collet through capacity of 14.5 mm. The Type W20 collets used were 19.7 mm in diameter, 73 mm long and with an unusual buttress-form thread of 0.780" x 1.666 mm pitch - a type also found on some Jones and Shipman grinding machines. A word of warning - confusion can arise because not all collets marked W20 are identical - some were made especially for Swiss Mikron lathes and these are 19.75 mm in diameter, 80 mm long and with either a 2.0 mm or 1.25 mm pitch thread. As an alternative, but at extra cost, a spindle was available with a 25-mm bore and its collet capacity increased to a more useful 19 mm (W25-type). For collet closing all spindles could be fitted with either the standard draw-in screw tube or a number of different quick-action lever closers, though use of the latter precluded the fitting of a bolt-on headstock dividing attachment. Although a screw-thread nose was standard on both sizes of spindle, the customer could choose (but on the smaller-bore spindle only) a rarely-found "miniature" version of the popular "D" camlock, a size D1-2" - this fitting being used on many examples exported to the United States. The screw-type spindle noses were M37.6 x 3 mm pitch with the early type just screwing on but later examples being fitted with a clamping ring, locked by a hexagon-socket head screw, to prevent nose fittings from unwinding when the lathe was run in reverse. At the front the spindle ran in a precision, double-row cylindrical-roller bearing and at the rear in a pair of selected precision ball races. Although Schaublin must have been satisfied that the standard headstock assembly would perform more than adequately they did offer, at extra cost, a set of "ultra-precision" bearings. However, although all examples seen by the writer have been equipped with anti-friction bearings, it is believed that early versions of the 102-VM, constructed before the 1940s, had a different arrangement and one similar to that used on the less highly stressed 102 plain lathes. If so, the spindle would have run in a pair of parallel-bore bronze bearings tapered and slotted on their outside and with a thread on the end - a similar arrangement being used on a variety of contemporary small lathes including Mikron (and quite ordinary Drummond B and M-Types of English manufacture). Slotted nuts on the threads, turned by a thin C-spanner, drew the bearings into tapered seats and compressed them slightly, so setting the running clearance. Longitudinal thrust was taken by a ball race just behind the spindle nose. It is essential to use only the highest-quality oils in a Schaublin headstock and, although it is sometimes difficult to arrive at a modern equivalent to the older types specified in the handbooks (for example on the round-head lathes: "a good quality mineral oil with viscosity of 2.5 degrees Engler at 50 degrees C", or the special "Kluber" grease used for the angular-contact bearings in the later square-head machines) most lubricant manufactures run web-based technical departments that will advise on an equivalent if they are supplied with the appropriate data. A dog-clutch engaged, 5 : 1 ratio single-lever-operated backgear was fitted (although the specifications sheets hint that this may have been omitted on request) and lubricated by an oil-bath with a sight-glass level indicator. Together with the standard 2-speed (750 and 3000 r.p.m.) 3-phase electric motor with a 2-step V-pulley drive to an intermediate countershaft - and a smooth-running 3-step flat-belt final drive to the spindle (maker's specification 102 VM-8.100) the headstock gearing produced a theoretical set of 24 spindle speeds. However, as some speeds were duplicated, the number of significantly-different ones was 18: these were: 40, 55, 70, 90, 120, 150, 170, 210, 270, 350, 450, 580, 840, 1100, 1400, 1800, 2300, 3000 r.p.m. Also known to have been available, but not listed in the catalogues and fitted to only a few machines, was a 3-speed motor - though no details of the Schaublin-approved specification appear to have survived.