Although the Logan 12-inch" lathe used the same bed as the 10 and 11-inch machines because of its slightly longer, more robust headstock its between-centres' capacity was one inch less in both its standard and long-bed versions at 23" and 35" respectively.
Supplied as standard, on a underdrive cabinet stand with 1 HP 3-phase variable speed drive - the lathe was also fitted with a screwcutting gearbox and power cross feed as part of its regular specification.
Significantly different to the smaller models the headstock assembly was fitted with a much more substantial, hardened and ground spindle - although this was also used by the 11" lathe, but in a lighter assembly. The bore of 13/8" allowed a collet capacity of 11/16 " and a generously-proportioned spindle-nose thread of 2.25"  x 8 t.p.i. However, at this sort of size and capacity, an L-00 series or Camlock spindle-nose fitting would have been far preferable to a thread, and indeed, the former was available, but only as an option and at extra cost.  The spindle, like that of all Logans of the period, ran on pre-loaded, grease-sealed precision ball bearings - and in the case of this 12-inch lathe, a total of four were used. An adaptor was supplied to sleeve the spindle nose from a No. 3 Morse taper to a No. 2 for regular work.
A full range of equipment to convert the lathes into production machines was available and included six-station capstan and lever-operated turret assemblies, lever and screw-feed cut-off slides with twin toolposts and quick-action collet closers.
The lightest 11" lathe weighed 1040 lbs, the heaviest 1075 lbs.