Pr?/a>zima Lathes Photo Essay
Built in the GDR - the Communist-controlled former East Germany - lathes advertised as "WMW Prazima" lathes were actually manufactured by the firm of Andr?& Zwingenberger. The models offered were all late versions of an earlier type that had been sold using both the manufacture's name and also "Georg Jacob" - who was actually the selling agent - and then, finally, in the 1970s, branded as if made by Saupe & Sohn of Georgstrabe 45, D-09207 Limbach-Oberfohna.
Of the Boley-like 8 mm "Geneva" type, the Präzima was available in three different forms, these being the very similar Z1, Z2, and Z3 all with drive by 3-step pulleys, the Z4 with electronically variable speed control and the Z5, this having a greatly increased centre height, variable-speed drive - but of otherwise of identical mechanical design and construction to the others.
The Präzima was advertised as being built upon the "unit construction principle" and available with: "...a wide range of special equipment allowing adaptation to the most various applications in production and maintenance". When supplied in a fitted box with accessories a number of different arrangements appear to have been possible with extras including: screw-feed compound slide rests - one with conical-faced micrometer dials the other cylindrical, a self-centring, ring-scroll 3 and 6-jaw chucks, faceplate with clamps, a set of wire, cone and fir-tree collets, box chuck, two tailstocks one to take runners (a set was supplied) and the other with a lever-action spindle, lapping attachment, wax chucks, flip-up hand T-rest, a safety pulley for turning between centres and various arbors - a full list in shown in the catalogues reproduced below.
One item missing from lathes sold in earlier years was a kit of parts to convert the lathe into a precision drilling machine, presumably the market for this type of lathe having moved away from individuals who needed a versatile system to one where the lathe would have been but one more tool in a well-equipped professional toolroom. However, one interesting - indeed possibly unique accessory- that appears to have survived the marketing department's pruning was the amusingly-name "Winkelwange". This device consisted of a hinged bracket, formed with two sockets one of which clamped over the tailstock end of the bed. Into the second socket could be fitted another section of bed bar and, mounted on this, the screw-feed compound slide rest to which was fastened a high-speed grinding and milling spindle driven - instead of by a traditional "overhead" - from a pulley on the end of an extended motor shaft. As the whole assembly could be hinged from horizontal to vertical, it allowed the operator to mill or grind material held by spindle-mounted fitting, a 3 or 6-jaw chuck, collet or faceplate
Some recent observations by the owner of a used example of the type (branded as an Andr?& Zwingenberger include:
?.the solid white oak varnished case has finger (box) joints and panel construction for the top and bottom with very interesting pivoting latches that are flush with the front side when closed - so allowing a very safe, positive locking.
With a centre height of 45 mm and 130 mm between centres, the lathe is a little short of 260 mm long . The bed is 25 mm diameter (it actually measures 24.99 mm) and is mounted on a nickel-plated foot with two 8 mm hex cap screws to secure the headstock and a 12.6 mm bolt and wing nut to clamp it to a bench. The bed is made from a solid bar of polished steel with a flat on top and grooved along the full length of the center line. It is stamped "G. Boley Germany" at one end while the other has a centre hole - with another hole lower down for an unknown use. The same name stamp can also be found on the base of the hand- rest base and underneath the saw table.
With an immaculate green paint finish the lathe uses a cast-iron headstock with an 8 mm bore spindle to take 8 mm collets secured with a steel draw tube having an aluminum handle. On the outer flange of the 3-step drive pulley is a circle of 60 division holes (with four larger holes evenly spaced every 15?to index a square) and indexed with the usual type of spring-arm with an detent pin on the end. The spindle bearings are plain bronze with ring-type adjusting nuts.
Two different cast-iron tailstocks, with black aluminum tightening nuts, are included with the lathe. The ordinary fixed version has the usual double-ended spindle, with male and female centers, whilst the drilling tailstock operates smoothly, has its own draw-in collet closer, an absolute maximum travel of 40 mm and a V-groove on the underside to prevent rotation. The adjustable (blackened steel) ring with screw lock located on the left side - though how this could be effective is difficult to see - a better position would be on the right hand side, between the tailstock body and the handle to limit travel.
With traditional dovetail construction and gib-strip adjustment - just 2 screws for the top slide but 6 for the cross slide - the compound slide rest is well made and has a smooth, even silky, feel. The 0.8 mm pitch feed-screws run through bronze nuts and are equipped with 0-40 divisions (= 0.02 mm per division) and neat, zeroing micrometer dials with friction locking. Useful travel of the top slide is estimated at 50 mm and 35 mm for the cross slide.
Included in the accessory kit are a number of useful items - through the tip-over T-rest does not match its base with any great accuracy and the two parts may well be of different origin as the filing roller-rest and saw table (20 by 40 mm) do not fit the hole - being larger by some 0.275" on the diameter of their support bars. Of 59 mm diameter the plain faceplate has one axial slot and adjustable angle plate, 44 mm long by 10 mm by 10 mm. The 85 mm diameter three-jaw faceplate is supplied with its own draw bar with a spring-center finder. the universal 68 mm diameter self-centering 3-jaw chuck can grip pieces internally and externally. The pivoting attachment appears to be of good quality as does a tailstock broche - the same as Nr. 15896 and 15 899 Georg Jacob model respectively. A number of collets, ring chucks, wax chucks and arbors complete the set..