American Tool Works lathe, 1912 14" High-Duty "Larktide"
Serial # 352.55 "Inspected by J.S."
70" overall length, estimated weight 2500 lbs
The headstock provides 8 spindle rpms in ratios relative to the input
shaft ranging from 1:1 to 1:(32 1/4). The center shifter has three
positions, the left and right engaging high or low gears through to the
spindle transmission. The lever's center position freewheels the input
shaft and releases a wooden brake shoe to press against one of gear
units on the backgear shaft. The brake's function is to stop the
spindle rotation and ensure it remains stopped. ATW shipped this model
lathe configured for line shaft operation or with a dedicated motor
according to the buyer's choice.
My lathe came equipped with a motor mount which was substantially
customized at some point in the past. I have an ATW manual which
suggests the dedicated motor configurations employed a gear train from
the motor to the input shaft. When I got the lathe, it was equipped
with fiber gears (mostly in poor shape) mounted with a most of an
original bracket. Since the geartrain was a mess, I opted to remove all
of it and use a v-belt instead. With an 1800 rpm motor installed, the
headstock requires a reduction between 3:1 and 3.5:1 down to the input
shaft to keep the spindle speeds reasonably close to spec.
With the vfd providing braking, the old mechanical brake is unnecessary
so the next step is to remove it and use the space for an oil pump,
filter, sightglass with distribution manifold and drips onto the
headstock gear units. This model lathe is strictly splash oiled and
tends to be messy when enough oil is inside for the lubrication to be
Bourn & Koch's production records indicate this serial # was a 14"
lathe, but unfortunately did not include the originial purchaser or other
information about the lathe.