With a reasonable amount of room in the cabinet. it was possible to install a multi-speed all-V-belt drive countershaft unit Six spindle speeds were provided, spanning 3000 to 8000 r.p.m., with 14 camshaft speeds for every spindle speed

Section through the nitrided spindle of a Petermann P3 spindle A parallel-bore bronze bush (1) was positioned behind the spindle nose and adjusted by being drawn into a tapered housing. At the other end (2) a pair of high-precision contact ball races was fitted capable of "micrometric adjustment". An additional bearing (2) was used to take axial pressure and belt tension from the overhung flat-belt drive pulley (8). The collet (4) was drawn into its taper by the usual type of toggle arms (3) with the draw tension finely adjustable by a screwed ring (5)

A relatively simple tooling set-up with four radial tools, two of which were set horizontally. Note the micrometer adjustment of each tool and the especially large thimbles on the horizontal slides. This was Petermann's "micro-differential" apparatus, where first setting of the micrometer took the setting accuracy to within 0.01 mm of diameter and the second down to 0.001 mm (0.00004").

P3 Screwing Attachment: used for all kinds of external threading operations: pendulum screws, jewel caps, jewellery and studs of all kinds. The attachment was driven by two belts, one running on the threading pulley the other on a pulley that caused the return of the tapping die. Between the pulleys was a double-taper friction clutch which, like that on a conventional tapping machine, was moved up or down to engage the chosen drive.

P3 Centring and Drilling Attachment: this unit allowed a part to be centred and then drilled. Two spindles were arranged, side by side on a slideway so that a cam could bring first one and then the other into its working position. A deburring device was available that, by withdrawing the drilling spindle at regular intervals, eliminated the build up of swarf. Only one spindle, that for drilling, was motorised the other being used only for centring

Screw-head Slotting Attachment. Similar is design to that shown for the Petermann No. 0, the unit for the Ps was mounted on a horizontal section of the lathe frame between the Rocking Arm and Screwcutting Attachment. The slotting saw was adjustable in all directions with a small hopper positioned beneath the saw to collect the finished parts.