Myford M-Type Countershafts
Copies of the Maker's Literature, Screwcutting Charts, etc. are available
Drummond Home Page EARLY 3 1/2" Drummond Larger Drummonds Round Bed Drummond
Rare 4" Drummond Flat Bed Headstock Comparison Admiralty Model M-Type Photo Essay
Early Original 31/2" 1912 31/2" B Type 1921 M Type 1925 M Type Little Goliath
The First Drummond Lathe Still in Use Round bed Backgears Walram
A set of photographs showing details of the very heavy, rear-mounted countershafts fitted, with some modifications and differences, to stand-mounted M Types from 1942 until approximately 1951. A picture of the bench countershaft assembly can be seen here.
|
A substantial cast-iron over-centre tensioning arm, with a right and left-hand threaded adjuster to allow the belt tension to be precisely set. The bearings were plain but held within ingeniously-designed housings where the points of two opposing and adjustable screws pressed into countersinks on either side of each bearing and both held them and allowed a degree of elf-alignment. This type of countershaft assembly was also used (from 1935) on the American Atlas 10-inch lathe (though with Hyatt roller bearings) and later on the Australian-built Hercus copy of the South Send 9-inch. |
||
|
The countershaft was enormously long and heavy and pivoted from a triangular plate bolted to the rear of the leg at the headstock-end of the lathe. |
||
|
The motor plate was supported on an adjustable rod that allowed the motor-to-countershaft belt tension to be set. Some lathes had their motor mounted underneath the plate and the adjuster arm connected to a lug on the countershaft itself. |
||
|
|
||
|
Both the two-step countershaft pulley and 3-step headstock-drive pulley were in cast iron the extra inertia of which helped to smooth out the drive from the commonly-fitted single-phase motor. |
||
|
Spindle-speed chart riveted to the inside face of the countershaft. |
||