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Blomqvist Lathes
- South Bend 9-inch Copy - 

Early Blomqvist Lathes

Even in Sweden, home to many makers of fine-quality machinery, the benefits of copying an established machine were recognised with both Storebro and the Blomqvist machine-tool companies producing their own lightly-modified version of the South Bend 9-inch "Workshop" lathe. Production of both would have spanned from the late 1940s until, it is believed, the early 1970s. Both plain and roller-bearing headstock models of the Blomqvist were made, the latter easily identified by the flat top to the headstock bearing area and the use of rectangular backgear guards. The maker's model designations varied with "BS" being the general type and BS-G used for the plain bearing model and BS-K for the roller -  presumably after Swedish "Glidlager" for sliding bearing and "Kullager" for ball-bearing. The BS-G was always supplied with a 1400 rpm motor - giving a spindle-speed range from 52 to 1200 r.p.m. - whilst the BS-K could be had with the option of a 2800 r.p.m. unit that gave 105 to 2400 r.p.m. Also available, at extra cost, was a choice of three different 2-speed motors:  2800 & 1400 r.p.m.; 2800 & 700 r.p.m. and 1400 & 700 r.p.m. The full type designation for each model also included the distance between centres - which could be 600, 800, 1000 or 1500 mm - with, for example, a BS-1500-K being a long-bed machine with a roller-bearing headstock. However, very early models, being a more direct copy of the South Bend original, had flat belt drive and were known as the Type  "SV" - and it may be that other (as yet unknown) versions were produced as well. However, precise catalogue specifications were not always adhered to with some (late) examples having a M38X3 spindle thread - instead of the 1.5" x 8 t.p.i. listed - and a screwcutting range (on the changewheel model) from 4 to 480 t.p.i. instead of the stated 4 to 112 t.p.i. Besides obvious cosmetic changes brought about by the use of new casting patterns, many other significant alterations were also incorporated: the bed was noticeably deeper with cast-in feet; the tumble-reverse lever fitted with an indexing plunger through its end instead of the side; the headstock spindle was increased in size to 17/8" and, although the bearings on early models were plain bronze bushes, roller races were employed on later machines. The plain bearings were, for a small lathe, relatively massive with the front being 58 mm long and with  inner and outer diameters of 47.7 mm and 54 mm diameter respectively; the rear bearing was 34.6 mm long, 34.8 mm inside and  40 mm outside. Thrust was taken by an SKF JH4-107 ball bearing. Both bronze bearings had two axial (horizontally disposed) oil channels - and two radial channels set near the ends - with oil supplied through a pocket in the casting aligned to the horizontal channel and connected to it by a drilling through the bearing.
Neatly fastened to the back of the bed, the countershaft used a single, wide central bearing with the large driven pulley on one side and the 4-step V-belt drive headstock pulley on the other. Like the original South Bend, Blomqvist retained a V-pulley on the motor driving to a flat pulley on the countershaft - an apparent contradiction but which worked well in practice and allowed a very quick change to be made between low and high speed ranges; just slipping the belt off the flat pulley, repositioning  it in the other V on the motor and rolling it back completed the job - and this also eliminated the need a separate, adjustable belt-tensioning device on that section of the drive. A simple but effective rectangular-form lift-up guard protected the spindle bull-wheel that allowed, when it was raised, a greater space for the operator to grasp and move the backgear release pin.
There is a possibility that Blomqvist engineers, as well as obtaining a South Bend to replicate, also acquired an English Boxford  - the saddle wings of their later machines are not the light, rounded South Bend type but the much heavier Boxford pattern with flatter faces, whilst the feed-screw micrometer dials on the compound slide are not the tiny, South bend originals but the larger ones as used on Boxfords from the early 1950s. The apron however was distinctly different to both the American and English lathes having a raised section across its front surface.
While the front cover of the screwcutting box, with cast-in guides to help locate the lever plungers, was altered, the internals of the box appear to have been copied from an English-threads version - the relative positions of the selector arms not being reversed left to right as they were on the  "all-metric" South Bend and Boxford versions. Further confirmation comes from the discovery that the lathe illustrated below is fitted with a metric-conversion changewheel set. The Boxford company, faced in the 1950s with a demand from schools and colleges for "all-metric" machines - and stuck no doubt with quantities of English components on their shelves and jigs and fixtures to produce them - supplied lathes with metric feed screws in the compound slide rest, but an English-pitches gearbox driven by metric-conversion changewheels. It would seem that Blomqvist, even though situated in an country well used to metric measures, may well have copied this set up. The lathe was also offered as a capstan version with a bed-mounted 6-station turret and an interesting cross slide that could be operated as both an ordinary screw-feed version and (by disconnecting the feed-screw) a lever-operated cut-off slide. Another addition was an unusual lever-action cut-off toolpost, designed to fit in place of the standard unit on the ordinary screw-feed slide. Early Blomqvist lathes are shown here

Blomqvist Type BS-600K. This was the least expensive version and equivalent to the South Bend Model C with screwcutting by changewheels and no power cross feed

Blomqvist Type BS-600K set up for production work with a cut-off/forming slide and a  self-indexing, bed-mounted capstan slide

Blomqvist 9-inch Model A lathe with an English-pattern screwcutting gearbox, power cross feed and a  4-speed V-belt drive headstock.

This Blomqvist appears to be fitted with a metric conversion changewheel set - thus, even for the home market, it would seem that the makers fitted an English-threads gearbox (the selection levers are disposed in the  English-pitch fashion) and an inch-pitch leadscrew.


4-speed V-belt drive headstock. Before WW2 South Bend had also offered the option of a 4-speed V-belt drive headstock together with a hardened spindle, but their catalogs entry hardly inspired the owners to choose it, stating: "The flexibility of the flat leather belt and the ease with which the belt may be replaced are responsible for its wide popularity and use". However, in later editions they did concede: "The positive powerful drive of the V-belt makes it especially desirable for manufacturing operations and for use in shops handling work which requires volume in production".

Altered from the earlier type with its linier screw lock, the cross-feed micrometer dial on later models had a distinctively Boxford look about it


email: tony@lathes.co.uk
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Early Blomqvist Lathe Model SV-600
- South Bend 9-inch Copy -

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