Drummond Radial-arm Drilling Machine
Manufactured from around 1910 into the 1930s, the Drummond radial-arm drill is relatively rare - and seldom seem to have been advertised by Drummond themselves - though they did appear in contemporary machine-tool catalogues though often lacking any mention of the maker. The drill was offered with two different drive systems: one a straightforward flat-belt type using a fast-and-loose pulley as a clutch on the input shaft and the other, remarkably, with a supplementary treadle system, integrated with the powered drive (consider for a moment the long-suffering apprentices having to work the treadle while their master fastened to the job in hand - it is unlikely that both tasks could have been accomplished simultaneously by the operator without some considerable practice and a strong right leg). The ordinary power drive system was simple but neatly arranged: from the fast-and-loose pulley at the bottom of the drill--with engagement of the striker mechanism by a handle on the front of the drill working through an enclosed linkage - a flat belt transmitted the drive upwards to a second pulley in line with the 23" x 12" table. From this point a shaft took the motion inwards to a pair of bevel-gears that turned a vertical shaft held inside the main column. At the top of the column a second pair of bevel gears turned the drive through 90°to drive a horizontal shaft - this in turn rotating, at its far end, a third pair of bevel gears to drive the spindle. It is suspected, but not confirmed, that some models had a lathe-like backgear assembly to obtain a set of lower speeds with enhanced torque.
Unfortunately, when equipped with the treadle mechanism the machine suffered the loss of its flat belts, the drive being instead by a round leather "gut" rope passing around the lower flywheel and rising to turn a small pulley at the end of the drive shaft. Such a system would have seriously limited the transmission of power to the drill bit and must be imagined that few so equipped would have been sold.
Intended for the smaller workshop, the drill was carried on a small cast-iron plinth beneath the main column, a simple leg at the other ends and fitted with a remarkably robust-looking table that was T-slotted on the top (23" x 12" as well as on both sides - these being 23" x 10". Movement of the head up and down the main column was by rack-and-pinion gearing through 9.5", a suitable large, full-circle handwheel being provided on the outer face of the column together with two cross-bolts to clamp the assembly in place once positioned correctly. Travel of the ball-bearing thrust spindle, by quick-action lever, was 4.5" with the greatest possible clearance between table and drill chuck face 12". Travel of the arm (by rack-and-pinion gearing) was 18", the maximum clearance between spindle centre and the inside of the column (the throat) 22" and the minimum 5".
A very useful feature of the Drummond was that the whole head could be swung round the column to clear the table and so reach really large or awkwardly shaped jobs sitting on the floor.
Fitted as part of the standard equipment was a drill chuck, this having a capacity of just 0.5" - a telling clue as to machine's limited working capacity
Should any reader have a similar drill - or literature about them - the writer would be interested to hear from you.