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LORCH Precision Toolmaker's Lathes - Page 1 of 2, 3, & 4
Types LL, LA, LAN, LLG, LLP &  LLPF
     Toolmaker's Plain AV1-K      Precision Plain: LLS, LLV  &  KD50    Toolmaker's: LLR(G)N,  AVR(G) &  BVIR(G)
Lorch Home Page   Toolmaker's Screwcutting Lathe AVI-L      Precision Screwcutting Lathe B27LZ
Toolmaker's Miniature: LAN, LLN & LLPN      Toolmaker's: AV, AVI & AVII   
Lorch dividing apparatus for watchmakers' lathes
Toolmaker's: BVII,  C,  B,  BVI & Chase Screwcutting   Larger Screwcutting Lathes D27 & BIIZ
Earlier Lathes for Production Work      Short-bed Lathes   
LAS Precision Screwcutting
      Post 1950 Accessories      Pre 1950 Accessories      Thread Chasing Lathes     Optical Thread Chasing

Starting life in the early 1900 the LL range of lathes was developed steadily over many years and even continued, with various suffixes (LLV, LLS, etc.) into the 1950s. It was the smallest of the company's Precision Plain-turning Toolmaker's models to have a version adapted, as the model LA, with full backgear, screwcutting with tumble reverse (in later years, when fitted with better guarding of the gears and other small changes, it was reclassified as the LAN). Of the same 65 mm centre height as the plain-tuning lathes in the series, the LA/LAN had a 600 mm long bed - but there the resemblance ended, for this was a miniature yet properly backgeared and screwcutting lathe. The 1 : 6 headstock reduction gear, in conjunction with a 2800 rpm drive motor gave 12 spindle speeds starting from a rather high 75 and extending through 105, 150, 210, 300, 415, 450, 630, 900, 1250, 1800 to a maximum of 2500 rpm. The 3 mm pitch leadscrew (accurate to 0.02 mm in a length of 200 mm) was driven through a tumble reverse mechanism and a set of changewheels - the full set comprising gears with 18, 20, 22, 25, 26, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, 80, 85, 90 and 100 teeth. Some versions of the lathe had a very unusual method of providing an automatic knock-off to the carriage sliding feed: two handles were provided on the apron -  a smaller one to select either "light" or "full" gripping and a larger one to close the bronze clasp nuts. When set in the "light" position the automatically disengage would work when using power sliding for ordinary turning jobs, whilst the full-engagement position allowed screwcutting - when the automatic knock-off could not, unfortunately, be employed. The effect of the small lever was to impart, via spring, a small preload to the clasp nuts to encourage their opening via the auto-knockoff mechanism; an essential part of the arrangement was a knurled screw, set above the clasp-nut lever, to adjust the depth of engagement of the clasp-nut drive pins in the closing cam plate. As on some other Lorch models a planetary gear system unit could be incorporated in the changewheel drive to provide an extra-fine sliding feed.
Two bed lengths of 500 and 600 mm (19.7" and 23.6") were available to give between-centres capacities of 225 mm (9") and 325 mm (13") respectively. Although the carriage was guided by a conventional V and flat way, on this model Lorch used a special form of guidance to retain the headstock and tailstock that consisted of a vertical face together with an angled way cut into the underneath of the slot that ran down the centre of the bed. As the locking levers were operated pressure on the angled surface pushed the units into perfect alignment against the vertical. The tailstock was available with both lever and screw-feed barrels with the former accepting the same collets as the headstock and the latter being without a morse taper but with a short 20 mm cone in its nose.
Super-hard, ground and lapped the headstock spindle ran at first in adjustable steel bearings (early 1930s) and then, at some undetermined point towards the late 1930s, in bronze replacements. For collet use both types accepted either a simple drawbar or lever-action closer. The recommended countershaft speed was 1000 rpm with an allowable top spindle speed of a little over double that. The compound slide rest was beautifully constructed with a usual-for-type long-travel top slide and, happily, a full length cross slide that offered superior support and an even rate of wear to its ways. The longitudinal travel of the top slide was 90 mm (3.5") and the cross travel 80 mm (3.1") -  a T-rest for hand work was included as part of the standard equipment. The shorter of the two lathes weighed 41 lbs (18.6 Kg) - and the longer 44 lbs (20 Kg). Several other versions were made including the LLPN fitted with a special type of headstock designed to be used for a form of thread chasing where the entire headstock spindle slide in and out of its bearings under the influence of a master thread and follower - further information about this process, together with details of the lathes on which it was fitted, can be found HERE.
Lorch was one of only a few manufacturers to ignored the long-time convention that turning a handle to the right produced an inward moment of the cutting tool and all models of this lathe had "cack-handed" screws fitted. One wonders how many jobs were ruined as a consequence in workshops were turners encountered more than one make of machine in a day's work. After 1950 the company saw sense and the replacement for the LAN, the beautiful LAS, had conventional screws.
The lathe weighed around 75 lbs and was available with a selection of countershafts and accessory drive units, driven from an "overhead" for high-speed milling and grinding - an example of which is shown at the bottom of the page. Most of the models shown on this page are as manufactured in the 1930s and 1940s - a range of earlier LL types will eventually be shown here.

65 mm centre height Lorch Plain-turning LL No. 1 Lathe with a No. 5 Compound slide rest cica 1930s and 1940s

Lorch LLPN with the headstock arranged for "chase screwcutting" where the entire spindle was induced to move backwards and forwards under the influence of a Master Thread - or hob - held on an extension to its left-hand end. This restricted the machine to short - but very accurate threads - and was intended for use in the optical and instrument industries.
A range of special Lorch lathes was later produced with this fitting - details can be found HERE.

The Model LAN was the smallest Lorch lathe to be fitted with a conventional backgear assembly and screwcutting by changewheels and leadscrew. This example appears not to have the selectable low/high pressure grip on the leadscrew. Photographs of a LA/LAN can be seen here

The Lorch Model LAN fitted to the wooden bench top No. 38 and driven by  the table countershaft unit No. 43a.
The overhead drive was employed to power grinding and milling heads clamped to the top slide - that shown being the Grinding Attachment No. 6. More pictures here

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LORCH Precision Toolmaker's Lathes - Page 1 of 2, 3, & 4
Types LL, LA, LAN, LLG, LLP &  LLPF
   Lorch Home Page    Newer Accessories Page 2    Newer Accessories Page 3   
Toolmaker's Plain AV1-K      Precision Plain: LLS, LLV  &  KD50    Toolmaker's: LLR(G)N,  AVR(G) &  BVIR(G)
Toolmaker's Screwcutting  AVI-L      Precision Screwcutting  B27LZ
Toolmaker's Miniature: LAN, LLN & LLPN      Toolmaker's: AV, AVI & AVII
Toolmaker's: BVII,  C,  B,  BVI & Chase Screwcutting   Larger Screwcutting Lathes D27 & BIIZ
Earlier Lathes for Production Work      Short-bed Lathes   
LAS Precision Screwcutting
      Post 1950 Accessories      Pre 1950 Accessories       Thread Chasing Lathes     Optical Thread Chasing

More information about Lorch Lathes is contained in various Sales Brochures; click HERE for details.