email: tony@lathes.co.uk
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Prototype Simonet Lathe

Simonet Home Page

Copies of the Maker's Working Instructions (12 pages) are available
for the Simonet DC-102, DD-102, DR-102 and DZ-450 lathes


The only example known, and stamped on many parts with the single digit 1, this fine-looking Simonet lathe was found in an old storage depot in Bern, Switzerland.
With a 150 mm centre height and taking 800 mm between centres, the lathe has what must surely be a unique design of bed. Made as a thick-walled, inverted triangle (with its open base at the top) milled into its top surface are two triangular depressions, each holding a hardened and ground way with a flat top and V-edges; the idea behind the arrangement being, presumably, to enable their replacement when worn.
Although fitted with metric and inch screwcutting, the arrangement of this is also unusual - the changewheels being housed in a compartment on the front face of the headstock and the drive shaft, rather than a leadscrew, running down the centre of the bed. Sliding and surfacing feeds are infinitely variable, being driven separately by an electric motor built vertically into the apron. Control of the feed rates is by potentiometers, the two controls knobs for which are fitted to the front face of the stand below the headstock. Selection of the feed direction is reduced to the simplest method possible, a lever pivoting from the right-hand face of the apron being moved upwards for power cross feed and downwards for sliding along the bed. Rather unusual for a "continental" lathe is the fitting of a cross slide with T-slots, though these are clustered rather close together behind the top slide and so of limited use. Able to be slid along the bed-mounted rack is a micrometer-adjustable carriage stop, its fitting in this position - rather than, as normal, to the bed - probably caused by the latter's unusual design of ways.
Drive to the spindle is by an infinitely-variable speed, belt-drive "variomatic" system, the opening and closing of the opposed pulleys being by an electric motor controlled by a small lever. The indicator for spindle speeds takes the form of  vertically-travelling "handle" on the control panel on the left-hand front face of the stand (just like that on the early Hardinge HLV) the two speed ranges - provided by belts, not belts and gears - spanning 30 to 400 r.p.m. in low range and 270 to 3600 r.p.m in high.
Both the cross and top slide screws and the carriage handwheel are fitted with large-diameter, finely engraved micrometer dials - while the cross slide and carriage handwheels must also be, for a lathe, unique in their use of a single-spoke design.
Appearing to be a form of CamLock system - but locked with screws - the spindle nose can take chucks and faceplates, etc, and direct-fitting W25 collets.
Two swing-out drawers occupy the front face of the stand, the left-hand one being fitted with a collet tray and holders for centres and tailstock fittings, while that on the right is intended for tool and accessory storage - both fixed and travelling steadies surviving with the lathe.
As no other example has come to light, nor any sales literature, might this be a Simonet prototype - or one example of a very short run in the dying days of the company?
Three videos showing how the machine is controlled are here, here and here



A unique design of bed? Made as a thick-walled, inverted triangle (with its open base at the top) the two hardened and ground ways were also of triangular section with flat tops and V-edges. Each of the pair was set in a triangular recess milling into the bed's top surface






Carriage power and screwcutting shaft

email: tony@lathes.co.uk
Home   Machine Tool Archive   Machine-tools Sale & Wanted
Machine Tool Manuals   Catalogues   Belts   Books  Accessories

Prototype Simonet Lathe

Simonet Home Page

Copies of the Maker's Working Instructions (12 pages) are available
for the Simonet DC-102, DD-102, DR-102 and DZ-450 lathes