|
In addition to the better known miniature jig-borer/co-ordinate milling machine that was also built in England as the Ultra, Excel and BCA the machine featured on this page was of more conventional design - and branded as both a "Leinen" (on the column) and "Boley Leinen" (on the head). A comparatively rare model, it dates from a period spanning from the late 1920s until the late 1930s and was manufactured by a Company more closely associated with precision watch and clockmakers' lathes. However, although at a glance it resembles a conventional milling machine, its head assembly is obviously adapted from one originally intended for use on a lathe - a course of action also adopted for their millers by other precision lathe makers such as Stark, Ames, American Watch Tool, Cataract, Stark, Pratt & Whitney, Sloan & Chace, Waltham, and Rivett. However, the Leinen was unusual for, by splitting the main column into two section, the makers allowed for the machine to be used either as a horizontal or vertical model - the upper of the two column pieces being removed from its machined ways and replaced by the headstock; the pictures below make the arrangement clear. As originally supplied, it is likely that the machine would have been driven from overhead line shafting - the two brackets at the bottom of the main column (where a motor platform could have been hinged) being undrilled. Subsequent owners have managed to lash up various systems, as evidenced by odd holes and welded brackets…..
10.375" x 4.2", the table had a longitudinal travel of 51/2", traverse of 3/4" and vertically of 6" - their being a maximum of 6" of clearance under the nose. One feed-screw handle was fitted, the other end of the table carrying a bracket to which could be fitted (once the screw-feed had been removed) a quick-action lever-feed mechanism
With an 1.172" x 8 t.p.i. thread, the spindle nose was backed by a 1.2" register and accepted a draw-in collet 85 mm long with a body diameter of 15 mm body and a head of 22 mm. An adjustable bronze front bearing was fitted, with a 1.102" bore, and double-opposed angular-contact rear bearings with a one-piece centre sleeve and the pre-load (not much) set by lapped split rings situated between the outer bearings--the splits also allowing the ingress of oil..
|
|
