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LLS, LLV & LLK High-precision
Instrument Lathes

More information about Lorch Lathes is contained in various Manuals, Parts Lists and well-illustrated Sales & Technical Specification
Brochures and can be purchased on-line here

   
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During the 1950 and 1960s Lorch continued their long tradition of manufacturing beautifully-made Precision Lathes designed for use in the instrument, optical and electronics industries. The most popular of these updated models were the plain-turning high-precision LLS and LLV and the backgeared,  screwcutting LAS. Both the LLS and LLV were of 65 mm centre height and available with either a standard bed, which admitted 225 mm between centres, or a longer one with a 325 mm capacity; the only difference between the two models lay in their drive systems.
Hardened, ground, finish-lapped and running in tapered, adjustable bronze bearings, the 10 mm bore spindle was driven either directly (LLS) from a 1400 rpm motor - with speeds of  742, 1030 and 1410 rpm - or through a countershaft assembly (LLV) with speeds of 450, 630, 900, 1250, 1800 and 2500 rpm. As an option a 2800 rpm motor was available which, of course, simply doubled the spindle speeds. The speed band of the LLS was rather narrow, and lathes have been found with what look to be factory-fitted 2-speed motors which gave a much improved range starting at 742 rpm and extending  to 2820 rpm. The maximum collet through capacity  was 6 mm and the non-through 8 mm. The cutting tool could be moved 90 mm longitudinally and 80 mm in transverse. All versions had traditional compound slide rests with, on most models, the option of a screwcutting feed thorough changewheels and a universal-joint shaft to the very long-travel top slide; unfortunately this is a fitting rarely found on a used example.
Looking more up-to-date the LLK had a motor mounted to the left of and slightly behind the headstock so that its V-pulley lined up with a countershaft held inside the lower part of the headstock casting. Final drive was by a flat belt running over 3-step pulleys, the countershaft assembly running in bearings held on an circular, eccentric plate that allowed the belt tension to be slackened for changes of speed.
The rare KD50 was marketed as a very special model, smaller than the other conventional Lorch precision bench lathes it's centre height was just 50 mm. Available in just one bed length of 400 mm, with a between centres capacity of  185 mm, the spindle had a bore of 8 mm and carried collets with a maximum through bore of 5 mm and a non-through of  7 mm. The bed of the lathe was formed into a large box-like casting behind the headstock on the back of which was built a very substantial countershaft unit. Fortunately the designer resisted the temptation to make the drive line too compact and spaced the motor well away from the headstock, the result being a smooth drive that worked effectively without excessive belt tension. With a 1400 rpm motor on a separate swing bracket at the back, spindle speeds of: 324, 490, 725, 1040, 1560, 2320 rpm were available. As an option a 2800 rpm motor could be fitted, doubling the speeds, whilst a few examples have been found with 2-speed motors giving twelve speeds in a much more effective range. Today, if the lathe still has its 3-phase motor, a variable-speed phase inverter would be the ideal solution and allow an owner to get the very best from the system..

An early example listed in the catalogues as the Model LL. This version is the toolmaker's lathe with screw-feed compound slide rest and collets retained in the headstock by a draw tube

Model LL set up for production work with a lever-action to the collet closer, cross and top slides and fitted with a form of tailstock mounted indexing turret.

Later 1950s Lorch LLS with direct drive from the motor. The LLV was fitted with a countershaft unit that increased the number of spindle speeds from 3 to 6

Above and below - a typical LVV installation and a machine bought originally by the UK Atomic Energy Authority

Lorch LLS fitted with a sliding headstock spindle and chase screwcutting. Details of how the sliding headstock spindle threading system worked on this class of lathe can be found here

Visible left is the bronze star wheel carrying six different thread pitches



Master-thread controlled headstock with sliding spindle (Lorch lathe Model AIIP)

Smallest model in the dedicated thread-chasing range was the Type LLPV

Apart from Swiss Autos and modern CNC versions of that and similar types, this early 1950s Lorch B VI PO-K was almost certainly the last conventional lathe to be constructed with sliding headstock thread cutting.

LORCH Optical Thread-chasing lathe with sliding headstock spindle Type B VI PO

Lorch LLK - final version of the Type with a neatly enclosed drive system

Lorch LL-K equipped as a finishing lathe with the 2-way No. 5K Lever-operated Slide Rest and a Drilling Tailstock with two No. 28C Change-over Drilling Spindles

Lorch LL-K as a capstan lathe with the No. 24F 6-Station Turret Slide, the No. 5F Cut-off slide and the No. 28A Lever-operated Collet Closer.

Lorch LL-K with the No. 5 Crank Compound Slide Rest, the No. 5A-1/2 Vertical Slide and the No. 7C Universal Milling Attachment. The drive was provided by an independent motor working through a V-belt and worm-and-wheel gearing. The milling spindle could be swung from vertical to horizontal and could take collet jaws with a maximum capacity of 8 mm





E-MAIL   Tony@lathes.co.uk
Home     Machine Tool Archive     Machine Tools For Sale & Wanted

Machine Tool Manuals   Machine Tool Catalogues   Belts

LLS, LLV & LLK High-precision
Instrument Lathes

More information about Lorch Lathes is contained in various Manuals, Parts Lists and well-illustrated Sales & Technical Specification
Brochures and can be purchased on-line here

   Lorch Home Page