Millers Falls No.1, 3, 4 & 5 eggbeater drills
Type Study
Return to Main Page

Unknown Maker's No.4 eggbeater drill; Type 0.

This type has a non-dished (flat) main gear casting with cast-to-shape teeth.
The gear ratio of 44/14 teeth associates it with other known Millers Falls No.4 drills, which also have a ratio of 44/14 teeth (that's decimal 3.14, every grade schooler's approximation of Pi).  This ratio (22:7) is pretty good in the sense that specific pairs of teeth will meet up again only every 22 times 7 equals 154 revolutions. Millers Falls finally applied this principle in the other drills of this study with the Type 5, which has a ratio of 56/13. This example has nifty pinstriping.

Note the three-way split of the spindle used to keep the bits centered in the chuck.  The early No.1 drills used a single split, giving the bifurcated spindle only two jaws.

The crank handle of this drill is about the same size and shape as that of the other No.4 drills, but it's attached differently. The attachment of the crank handle consists of a straight shaft pressed into the gear casting and then peened over a small, contoured, brass washer outboard of the handle.  Later, the attachment was changed to a headed pin that was peened on the inside face of an extended crank. Note also in the composite image above that the toothed side of the main gear has lost about half of the tooth that was intersected by the shaft of the crank handle. This error in design led to introduction of the headed crank pin.