email: tony@lathes.co.uk
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Kärger DL Series Precision
Leadscrew Lathes
- beginning circa 1892 - 
Kärger Home Page  1950s Precision Kärger Type DL1   
1930s Kärger Type DL2   1920s Screwcutting  DL Lathes   
Karger Sliding-spindle Chase Screwcutting   Post WW2 Lathes   
Precision Bench Karger   Restored  Kärgers


One important development for the company was the introduction, in 1892, of their first "precision leadscrew" models, the long-lasting DL series. This came about as the result of  enquiries by Dr. Loewenherz, the director of the P.T.R. (Physikalisch-Technischen-Reichsanstalt)  in Berlin, a standards organisation similar to National Physical Laboratory  in the UK. Dr. Loewenherz was working on a new metric thread system (flank angle 53°8`) for use in precision trades such as watch making and instrument production. Needing a suitable lathe on which to turn male and female micrometer screws, taps and other items needed to launch the new thread-system the P.T.R. turned to Kärger. The lathe supplied had a 2.5 mm pitch leadscrew, a set of 17 changewheels, and could generate pitches from 0.1 to 2 mm and up to 6 mm pitch on multi-start thread. A special spring-loaded and lever-operated support was provided - to prevent work from bending as the threads were cut - and there was also a simple but ingenious eccentric-operated slide system that permitted a quick retraction of the turning-tool as the end of the job was reached. The top slide was retained by an easily released and locked cone fitting and a degree scale provided to gauge the angle setting. Cross and top-slide feed screws were of 1 mm pitch - though. as was common at the time, no micrometer dials were fitted. In addition to the spring-loaded supporting fixture a number of other accessories were included with each new lathe: a centre with drive dog, 2 hollow centres, catch plate, drill chuck, a choice of stand-mounted treadle system with a flywheel or a ceiling-mounted reversing countershaft--and even three connectors for the round lather "gut" drive ropes. With a ceiling countershaft the price was 13,500 RM (Reich marks) and with a treadle movement 14,125 RM. Other accessories included 7 gears to cut English threads( 450 RM), a bell chuck (150 RM), 2-jaw chuck (225 RM), a fixed steady (240 RM) and a travelling steady (60 RM).
By 1898 the
Loewenherz thread-system had been supplanted by the present metric (SI) thread-system with its flank angle of 60°.
The DL Series - much modified through several versions - continued to be manufactured until the 1950s though it remained faithful, until the last, to design features employed in earlier decades..

Kärger DL1 Precision Leadscrew Lathe

The larger Kärger DL2a precision lathe

Kärger DL2a precision lathe


Kärger DL4c precision lathe with power  sliding and surfacing

Kärger DL3n lathe. This model was available with swings of either 160 or 172 mm and with 750 or 1000 mm between centres

Above and below: dimensions of the Kärger DL3n lathe


Kärger Home Page  1950s Precision Kärger Type DL1   
1930s Kärger Type DL2   1920s Screwcutting  DL Lathes   
Karger Sliding-spindle Chase Screwcutting   Post WW2 Lathes   
Precision Bench Karger   Restored  Kärgers


Kärger DL Series Precision
Leadscrew Lathes
- beginning circa 1892 - 
email: tony@lathes.co.uk
Home   Machine Tool Archive   Machine-tools Sale & Wanted
Machine Tool Manuals   Catalogues   Belts   Books  Accessories