Long enjoying a fine reputation as a maker of high-quality lathes - together with a small range of milling machines, from the 1950s onwards the Weiler Company concentrated on a relatively limited range of conventional lathes including simple plain-turning bench types, production capstan and toolroom-class screwcutting models. Models produced included the Praktikus, LZ330, Primus, Condor, Commodor, Ergodor, Matador, Turnomat and a series known as the HP, LZ, LD, MD, MF and RD. Today, in addition to some CNC machines, the Company still manufactures high-class manual lathes - one of the few surviving makers of such items for which there is a steady if limited demand.
A less expensive lathe than the contemporary Matador and Condor, the Praktikant was built in Early (Mk. 1) and later (Mk. 2) versions - the latter easily recognised by the angular styling and use of dials instead of levers on the headstock and screwcutting gearbox. This article deals only with the older version as current until the early 1980s.
With a 140 mm (5.5-inch) centre height Praktikant was built to DIN 8605 toolroom standard - though it was, as its name might suggest, a lathe intended for ordinary work and employment as an advanced training lathe in schools and colleges. Two between-centres capacities were offered: 500 and 800 mm; the shorter of the two was mounted on a one-piece, enclosed cabinet stand made from welded and braced sheet-steel. The left-hand compartment housed the drive system, the right-hand the coolant tank and electrical switchgear with the centre section forming a locking tool and accessory storage compartment. The long-bed 800 had its stand formed as two welded sheet metal plinths, one under the headstock the other beneath the tailstock with, between them, a slide-out chip tray mounted on four rollers and inclined slightly to the rear. The left-hand plinth held the drive system and the right-hand side the coolant unit and electrical equipment - including the hard-to-reach and dangerously remote switchgear.
Unlike the more expensive LZ330, Condor and Matador models with their choice of variable-speed drive or a 9-speed pre-selector gearbox, the Praktikant used, in conjunction with headstock backgears, a simple 4-speed gearbox, remotely mounted in the base of the cabinet stand. Lubricated by an oil bath, the box held hardened and ground gears, in an alloy steel, running on splined shafts supported in ball races. Control of speeds was by a large-diameter, wavy-edge handwheel, mounted to the left-hand side of the headstock-end, with a direct reading speed-indicator scale. Drive from gearbox to headstock spindle was by twin V-belts, as was that from the motor, this being mounted below the gearbox, on a hinged plate to allow adjustment of belt tension. As genuine, matched sets of V-belt pairs now appear to be unavailable, (and a pair of unmatched, ordinary belts can cause noise and vibration), today the solution is to use a belt of the accurately made T-Link type.
Early models appear to have been fitted as standard with a 2 h.p. single speed motor, though with the option of, at first, a 2-speed 1.4/2.4 h.p. unit and later a more powerful 1.5/3.0 h.p. - this latter fitting eventually becoming part of the ordinary specification. With the late-type 2-speed motor fitted, the base-mounted gearbox and backgeared headstock combined to give sixteen speeds: 42, 67, 84, 110, 134, 175, 220 and 350 r.p.m. in backgear and 241, 383, 482, 630, 765, 1000, 1260 and 2000 r.p.m in open belt drive. With the single-speed motor the eight speeds available began at a low of 84 r.p.m. (a tad too high when a beginner was attempting to screwcut) and rose to the same high of 2000 r.p.m. Electrical control of the motor's stop, start and reverse was by a handy lever pivoting from the apron's right-hand face - the rod it operated being connected to a switch held within the right-hand cabinet leg; unfortunately, rather low down on the front face of this leg was also the location for the electrical switchgear, non of which were duplicated near the headstock. Should the operator's have been involved in an industrial-quality accident, not having immediate access to an emergency stop button would have seriously impaired his or her chances of avoiding serious injury. If you own a Weiler, arranging a kill switch on or near the headstock - or, as a minimum, one between the stand legs - would be a wise precaution.