The Ames bench miller was designed as a very high-quality, precision tool on lines very similar to those made by Pratt & Whitney, Waltham, Rivett and Cataract - where the head from a Precision Bench Lathe was employed either unchanged or lightly modified for its new role.
The pivoting table, with a working surface 19" long by 2.5" wide and movements of 19" longitudinally, 3" in traverse and 7.5" vertically had a single, central T slot and was formed into the same cross section as the bed of the Ames Precision Bench Lathe. Its slideways were formed from hand-scraped, 45 degree Vs - with adjustment for wear. The longitudinal feed to the table could be released from its screw operation and activated instead by a quick-action rack and pinion gear whilst a pivoting base allowed the table a full 45 degrees of turn either side of its central position.
All three feeds were fitted with friction-type, zeroing micrometer dials and the feed screws milled with Acme-from threads running through long bronze nuts; the elevating screw was fitted with ball-bearing thrusts operating within hardened-steel retainers.

Ames Precision Bench Miller with a lathe headstock utilised as the cutter holder. Mounted on the table is the special Ames Dividing Head, with a tilting spindle, which could be set at any angle from 10 degrees below horizontal to 5 degrees beyond perpendicular. The standard indexing plates gave divisions from 2 to 312. The maximum distance between the head and tailstock centres was 10.5" and height above the bed 83/8"

Vertical Head Attachment
This unit was a direct replacement for the standard head and accepted the same collets. The main drive pulley was 4.25" in diameter and the rear idler pulleys, running on ball bearings, 3.5". The unit was designed to be run from a two-speed countershaft at 585 and 160 rpm.
The spindle nose was 8.25" above the table - and the unit weighed 40 lbs.

Overarm Cutter Head
This accessory was designed to overcome the natural limitations of the standard head which, with its unsupported cutters, was only able to take light cuts.
The standard collets could be used when stub milling was undertaken - and the horizontal arbor was provided with hardened and ground spacers. Two rings of indexing holes were provided, one on the front pulley flange, the other at the rear.