Classic_Boat_2016-02

RECIPROCATING DRILL

STORY AND PHOTOGRAPHS

ROBIN GATES

Turn to the power drills section of a

tool catalogue and the range of

makes, models and features boggles

the mind. A century ago the situation

was no less confusing with the

boatbuilder being offered dozens of

different tools for boring a hole by

hand. Breast drills, eggbeaters,

braces, push drills and Archimedes

drills in a multitude of models from

myriad rival manufacturers were vying

for a coveted slot in the craftsman’s

tool chest. But a boatbuilder browsing

Goodell-Pratt’s catalogue in the 1920s

would have been drawn to this No 101

reciprocating drill because it was

designed with the boatbuilder in mind.

The essence of the drill’s mechanism

lies in two helical grooves in the

polished steel spindle and, within the

travelling handle, a bronze centre nut

which follows them. As the handle is

moved back and forth its linear

motion is converted into rotational

motion of the spindle and the chuck

holding the drill bit. The travelling

handle of an earlier model was

smaller, sufficient only for a two-

fingered grip, whereas the elongated

handle of the boatbuilder’s version

accommodating the entire hand

performs better in both vertical and

horizontal positions.

The compactness of the

mechanism certainly lends itself to

the tight corners of a boat interior

where there may be insufficient

knuckle space to swing a brace

through its 10-inch circle. That said,

the reciprocating drill develops only a

fraction of the brace’s torque and the

going can be hard if boring oak or

teak. If extra torque is required the

travelling handle can be locked

temporarily by two pins at the chuck

end of the spindle which engage in

notches in the leading end-plate of

the handle. This is also useful for

starting a hole cleanly. Meanwhile the

supporting hand applies force via a

comfortable mushroom-shaped pad

turning silently on ball bearings.

In terms of functionality the

reciprocating drill lies somewhere

between the simple gimlet and small

eggbeater drill, boring everything

from tiny pilot holes to ¼in (6.4mm)

clearance holes. The quiet rhythm of

its rotation severing wood fibres at a

human pace compares to the power

drill as the oar compares to the

outboard motor.

NEXT MONTH: The micrometer

Clockwise from

above: Larger

than a gimlet,

slimmer than an

eggbeater drill;

hardwood

pad for the

supporting hand;

pins on the

spindle locate in

the travelling

handle

Traditional Tool