Little known outside their native land, Friedrich & Söhne & Co. manufactured a range of industrial-class lathes including engine (centre), turret, production, high-speed production - and also a horizontal boring machine. In addition to his interest in lathes, Harald Friedrich also founded the Alzmetall Company, a famous and very successful German maker of pillar and bench drills.
Developed during the 1950s in co-operation with Dr. Ing.F.Eiselem, a professor at the Munich Technical College who occupied the chair of Machine Tool Research and Technical Instruction, the company's very heavily constructed, 250 mm (9.8") centre height "Berlin" LD-10 and LS-10 lathes were probably their best known export and could be had in either standard form as the Type L with Model Types A,B,C and D) or as the Production Type P that had one additional Model listed, the Type S. The machines were advertised as being assembled on what was called a "Building-up System", a means of providing a customer with exactly the specification required yet still able to be assembled in a factory working to the normal constraints imposed by a regular construction processes.
Especially deep and rigid, the 400 mm (25.7") wide bed was formed as part of the massive, cast-iron stand cabinet, braced by triangulated ribs between its walls and carried hardened and ground flat and V-ways arranged in a rather unusual way - those at the front being set below the level of those at the back. The front V-way reflected a fashion of the time where its outer surface (to better absorb wear) was made much wider and set at a shallower angle than the steeper, shorter inner side that took most of the tool thrust. Because the bed ways abutted against the front face of the headstock, and did not run on past them at front and back, the saddle had the cross slide mounted towards its left-hand side to allow the cutting tool to reach the spindle nose.
Drive and speeds
Held in the headstock-end of the stand, the drive system consisted of either a separate speed-change gearbox (splash lubricated with hardened and ground gears and shafts) or a mechanical variable-speed unit, using traditional expanding and contracting pulleys - both types being suspended on a self-contained swinging arm by which means the final drive to the headstock, by four V-belts, could be adjusted. Both variable and conventional drives were supplemented by gearing within the headstock, this consisting of hardened and ground shafts and gears running in anti-friction bearings and lubricated by splash. The main spindle, fitted with a No. 5 Morse taper, was bored through a comparatively tight 41 mm (1.6") and ran in adjustable, high-precision double-row cylindrical roller bearings, the one at the front being 90 mm (3.5") in diameter. Although one would have expected the lathe of this size and weight (around 1650 kg or 4620 lbs) to have had its nose formed as a CamLock, American long-nose taper or some form of DIN flange fitting, it was actually a screw thread - a rather inadequate fitting.
Driven by a 5 h.p. or, to special order, a 7 h.p. motor, spindle speeds varied according to the particular model with the A having a choice of four spindle speeds spanning 67 to 540 r.p.m. 95 to 760 r.p.m. or 130 to 1040 r.p.m.; the Model B with eight speeds of 33 to 380 r.p.m., 47 to 540 r.p.m. 67 to 760 r.p.m. or 95 to 1040 r.p.m.; the Model C with a choice of twelve speeds, either 30 to 380 r.p.m. 42 to 540 r.p.m., 56 to 760 r.p.m. or 84 to 1040 r.p.m. and the Model C was fitted with an infinitely variable-speed drive system that could give, to a customer's preference, either 16 to 920 r.p.m. or 23 to 1300 r.p.m.--the rate being controlled by a long lever emerging from a boss at the bottom of the headstock-end plinth
Electrical control of the spindle - stop, start, reverse and braking by a counter-current system - was by a third-rod system with two operating levers, one pivoting from the right-hand face of the apron and the mounted just outboard of the screwcutting and feeds gearbox. On the variable-speed model, to inform the operator of how fast the spindle was turning, a neatly cowled rev counter was fitted on top of the headstock.