Manufactured by Boley & Leinen, Werkzeug-und Machinenfabrik, Postfach 64, 7300 Esslingen, Germany the "Leinen" FM1 Micro-precision Miller/Driller was a super-accurate machine intended for the finest and most delicate of work in research and development laboratories. It was designed along the lines of a European-style universal precision miller as produced by, amongst many others, Schaublin, Thiel, Deckel and Christen where a T-slotted (330 mm x 128 mm) vertical table - with movements vertically and longitudinally (left to right) - was used to mount a (300 mm x 130 mm) right-angle work table of either a plain type or one that could be pivoted forwards in the longitudinal direction and to both sides in the traverse. To provided a traverse movement the overarm was arranged to move forwards and backwards and carried either a horizontal or vertical milling head.
With a table travel of just 1 mm when turned once, the table feed screws were of a very fine pitch and carried scales engraved with 0.01 mm divisions; they drove the 300 mm x 130 mm table through a vertical travel (Z axis) of 130 mm, a longitudinal (X axis) of 180 mm and the overarm through 90 mm (Y axis). All the table and head movements could be run under power from rather complex electro-mechanical drives that gave very useful, infinitely-variable feed rates of up to 30 mm/min via a separate control box.
Powered by a variable speed 170W, 36 Ncm torque DC motor, the vertical and horizontal spindles had a maximum speed of 10,000 rpm and carried original-type Boley & Leinen WW Type a31 collets with 8 mm shanks, a maximum through bore of 4.4 mm and a blind capacity of 7.0 mm
Although the FM1 was relatively compact - just 520 mm long, 500 mm wide and 800 mm high - it was very heavily built with rigid, thick-walled castings and weighed 120 kg in basic form - or 140 kg when fitted with the optional electrical and electro-mechanical drives and a 3-axis digital read-out.
Another interesting Leinen machine was a precision miller/driller/jig-borer made until the 1940s and based on Wolf Jahn designs as originating in the 1800s..

The Boley & Leinen FM 1 Micro-precision Milling and Drilling Machine fitted with a dividing unit that could be turned by hand or motor-driven clockwise or anti-clockwise through 360º. The unit was fitted with a digital read-out (shown on the bench) which indicated angles down to seconds of arc - or in decimal degrees.