email: tony@lathes.co.uk
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Clausing 12-inch 6300
Clausing Home Page   Clausing 100 & 200 Series & 4800 & 6300 Models   
10" Model 4900   12" Model 6300   12" Model 5400   Clausing/Colchester 
Clausing Accessories   A History of the Clausing Company - by Don Clausing
 
Clausing Millers   
Fortis-branded Clausing   Clausing "Broadway"
Clausing 5900 Series Lathes - Serial Numbers

Manuals, Instruction Books Parts Lists and Reproduction
Catalogs are available for most Clausing lathes



During the 1950s and early 1960s the Clausing Division of the Atlas Press Company, Kalamazoo, Michigan, USA sold two very similar 12" lathes, the 6300 and 5400, each based on the same flame-hardened bed.
The 6300 was available with either a continuously variable speed drive system, which gave a range of 43 to 1300 rpm, or with a geared-head drive that, with a single-speed motor,  provided ten spindle speeds from 30 to 1300 rpm. Fitted with the optional two-speed motor 18 speeds spanning 15 to 1300 rpm were available; the 6300 was originally the Model 200 and the 4800 the Model 100.
An optional extra for either type of drive was a combined multi-plate clutch and brake unit that could instantly start and stop the spindle whilst leaving the motor running; an important consideration if a single phase motor was fitted  (the fewer times they are stopped and started, the better their long-term health). The operating handle for the clutch/brake unit was mounted on the front face of the stand, immediately below the screwcutting gearbox - a picture can be seen on the Model 5400 page.
On the 6300 the final drive to the headstock was by twin V belts (3 on the belt-drive 5400) that acted directly on a pulley fastened to the outboard end of the L00 taper,  headstock spindle. This novel design meant that a separate input layshaft was not needed, although the final number of shafts and gears was the same as in a more conventional lathe of the same era such as a Colchester or Harrison.
Surprisingly for a lathe of this class no separate power shaft was fitted; instead, the leadscrew, as in many smaller lathes, had a slot running its full length that drove the various gears (via a key within a worm gear on the apron), that provided power sliding and surfacing feeds.
The screwcutting gearbox was completely enclosed and supported the leadscrew on two Timken roller bearings; like the substantial double walled apron, it ran in an oil bath.
Details of later Clausing lathes - the 5900 with redesigned variable-speed drive and others with the "squared off" appearance - will follow..

Clausing 12" lathe Model 6300 circa 1959

Distinctive apron controls of the 12" Clausing 6300/5400 lathe.
A single, central, lever controlled the power sliding and surfacing selection.

Clausing Model 6300
Timken taper-bearing headstock with outboard twin V-belt drive and L00 spindle nose fitting

Optional variable-speed drive unit fitted with clutch and brake control

The tailstock was fitted with a 3 Morse centre with tang knock-out
and very substantial clamps for both base and barrel.

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


Clausing 12-inch 6300
Clausing Home Page   Clausing 100 & 200 Series & 4800 & 6300 Models   
10" Model 4900   12" Model 6300   12" Model 5400   Clausing/Colchester 
Clausing Accessories   A History of the Clausing Company - by Don Clausing
 
Clausing Millers   
Fortis-branded Clausing   Clausing "Broadway"
Clausing 5900 Series Lathes - Serial Numbers

Manuals, Instruction Books Parts Lists and Reproduction
Catalogs are available for most Clausing lathes