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Tom Senior - Older Milling Machines

Instruction Books and Catalogues are available for the Senior range

Senior Home Page   Senior Lathes   Senior Shapers & Planers   Price List
E Type   Junior Horizontal/Vertical   Light Vertical   VS   Major ELT   Older Millers

Tom Senior's first milling machines were a pair of small, very-well made but light-duty flat-belt drive horizontal models with traditional round overarms and intended for mounting over the front edge of a bench. Although the "S" Type was designed for model and other types of light engineering, even so the table was enormously deep and the end of the main spindle incorporated both a No. 2 Morse taper and a drive slot, so easing the direct load on the taper under heavier cuts. The 1.25" diameter spindle bearings, protected by dust covers and felt seals, were in bronze and two Hoffman ball thrust races absorbed spindle axial loads in both directions. However, one weakness of the design was the use of a hardened point on the end of the drop bracket (instead of a proper bearing) to support the arbor. With not only a significantly better cosmetic appearance than other small millers on the market, all the sliding surfaces were also ground and then hand frosted - and with the exterior surfaces of the 14.5" x 3.625" table also finish ground. The square-thread 10 t.p.i feed screws were not fitted with micrometer dials - though they were available at extra cost, as was (in the absence of a backgear for slow speeds) a large drive pulley to fit on the end of the spindle. Early tables had just one T-lot - later ones had three - with movements of four inches across, twelve inches laterally and ten inches vertically. The flat-belt drive cone pulley had diameters of 6 inches, 4.5 inches and 3 inches and accepted a belt 1.25 inches wide. The machine weighed approximately 100 lbs.
Senior's other early miller was a rather more robust and better-specified machine, the "Heavy Bench", available in two sizes the No. 0 and the No. 1. This was an industrial-class model and, with its self-contained drive system, a heavy cast-iron main column and an unusually large base that held the motor and coolant equipment, more like the machines made by Senior during the 1950s ..

Later-model Tom Senior "S" Type miller for mounting over the edge of a bench.
Note the simple means of supporting the arbor end.

Tom Senior "Heavy Bench" horizontal miller with backgear and power feed to the table. This was available as either a No. 1 or No. 2 Model. Exhibiting all the qualities of later Tom Senior products this belt-drive, backgeared miller was both well made and finished. Note the design of the feed screw flanges at the end of the table and knee. However, even by the standards of the late 1930s, it was of a distinctly old-fashioned appearance with very small micrometer dials.

Tom Senior Model "0" and (another, different) Model "1". The former had a table of 15.5" x 4" (power-driven from a 3-step pulley and round leather belt) with three T slots and movements of 4 inches across, 12 inches laterally and 8 inches vertically. The spindle, fitted with a slotted drive end and a No. 2 Morse taper, was driven by a 1" wide flat belt and incorporated a lathe-like backgear assembly in its drive. The spindle-speed range depended on the type of countershaft employed - normally a remotely-mounted wall or ceiling unit - but could range from as low as 25 to as high as 1000 rpm. The machine's overall dimensions were 20" wide by 24" back to front and 24" high; complete with a countershaft the weight was 196 lbs.
Looking almost identical to the Model "0" the Model "1" was 8 inches wider, 12 inches deep, 8 inches higher and weighed (with its larger countershaft) an extra 144 lbs. The 23" x 6" table had 6 inches of cross travel, 17 inches of lateral and 11 inches of vertical. The spindle was increased in size to accept a No. 3 Morse taper (with a drive key) and the flat-belt drive cone pulley had steps of 5.5", 4.5" and 3.5" driven by a 1.5" wide belt.
Both millers could be fitted to a compact, cast-iron stand which carried the Senior name cast into the side; strangely, apart from some vertical and slotting heads, no Senior miller of any age appears to have carried its maker's name cast into, or fastened to, the main components.

Tom Senior "Heavy Bench" horizontal miller with backgear and power-feed table

Instruction Books and Catalogues are available for the Senior range

Tom Senior - Older Milling Machines
Senior Home Page   Senior Lathes   Senior Shapers & Planers   Prices
E Type   Junior Horizontal/Vertical   Light Vertical   VS   Major ELT   Older Millers

email: tony@lathes.co.uk
Home   Machine Tool Archive   Machine-tools Sale & Wanted
Machine Tool Manuals   Catalogues   Belts   Books  Accessories