Continued:
With 66 different threads available, without changing or resetting any gears on the quadrant arm, the quick-change gearbox gave and was also provided, in best tradition of high-quality lathes, with an additional drive by means of a belt that gave feed rates one-half those by gear - the former ranging from 0.120" to 0.002" per revolution of the spindle, whilst the belt feed gave from 0.60" to 0.001", or down to as low as 0.0001" by additional manipulation of gears on the quadrant arm. With extra changewheels it was possible to cut all prime-number threads from 1 to 150 per inch, all threads that were multiples of 5 from 5 to 150 per inch and all threads that were multiples of 10 from 10 to 1000 per inch. Metric transposing gears were also available and could generate  threads from 0.1 mm to 15 mm.
Built to a tolerance accuracy of plus or minus 0.0005" per 12" of lead the "Hendey Super-Precision Leadscrew", was provided with an authentication certificate and used only for screwcutting - a separate shaft was used to transmit power to the apron.
Cast in Hendey's own foundry from a mixture of irons, a high percentage of steel scrap and controlled amounts of nickel, chromium and manganese the bed was formed from a metal of an exceptionally close-grained nature, to a specified Brinell hardness and possessing a genuine potential for long life and sustained accuracy. Running on two V-ways and equipped with bronze wipers lined with Duprene the saddle carried a dial thread indicator as standard. The apron was of the double-walled type with shaft bearings in both walls, including that for the rack-drive pinion; power sliding and power surfacing was fitted, each engaged by a friction clutch operated by its own screw-in knob.
Of especially sturdy construction the set-over tailstock employed a barrel clamp that drew the spindle to the centre - whilst applying an upward pressure to keep it in alignment with the headstock spindle. The tailstock clamping arrangement was a form of eccentric (subject to Patent No. 1,666,484) and the barrel graduated in 1/32" and engraved with a centre line to assist in the setting of tools.
In common with other toolroom lathes a taper turning attachment was high on the list of desirable extras - and on the Hendey was mounted on hand-scraped surfaces at the back of the bed and accurately leveled with the top of the lathe ways. Whilst the attachment's normal range extended to 3 inches in the foot if steep inclines were required then it was possible, by bringing into operation the simultaneous engagement of the screwcutting and power cross feeds to produce tapers of up to 9 inches in the foot. In addition, and like the Hardinge HLV lathe, if the longitudinal and cross feeds were engaged simultaneously, the tool followed a path that formed an angle of 45' with the centre line. By using the taper attachment in combination with these two feeds, the angle could be increased or decreased to form a minimum angle of 41 degrees and a maximum angle of 48 degrees. One end of unit was graduated in degrees and the other in inches-per-foot, giving an included angle of 15 degrees, or approximately 3 inches in diameter per foot. The maximum travel at any one setting was 9 inches.
Supplied with the lathe were a large T-slotted faceplate, a driving plate, micrometer carriage stop, fixed steady, two centres, a dial thread indicator and a selection of spanners; the only options were a taper turning unit and a set of draw-in collets..

Headstock with collet adapter - and showing the graduations used to assist with machining multi-start threads.

With 66 different threads available, without changing or resetting any gears on the quadrant arm, the quick-change gearbox gave and was also provided, in best tradition of high-quality lathes, with an additional drive by means of a belt that gave feed rates one-half those by gear

The apron was of the double-walled type with shaft bearings in both walls, including that for the rack-drive pinion; power sliding and power surfacing was fitted, each engaged by a friction clutch operated by its own screw-in knob.

The set-over tailstock was especially sturdy and employed a barrel clamp that drew the spindle to the centre - whilst applying an upward pressure to keep it in alignment with the headstock spindle. The tailstock clamping arrangement was a form of eccentric (subject to patent  No. 1,666,484) and the barrel was graduated in 1/32" and engraved with a centre line to assist in the setting of tools.

The drive system differed only in detail from that employed on contemporary toolroom lathes of similar quality; a D.C. generator was housed in the cast-iron lathe stand and driven by a standard 3-phase A.C. motor mounted above it. The output from the generator was controlled electronically and passed to a 3 HP DC motor (thus maintaining a high torque at low speeds) that  drove the headstock spindle via three V belts.  The smaller English Cromwell lathe used a very similar system.