Millers Falls No.2 drill, Type D/C

Millers Falls No.2 Eggbeater Drill Type Study
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Type DC

This drill looks nonsensical because it has the frame used with the "little railroad car wheel" but also has two pinions. One or the other feature has to be superfluous. This drill is apparently a prototype used to try out a way of making the transition from the LRRCW models to the widespread two-pinion models.

The crank logo is that of Type Post-E.

The second pinion was installed with a design that was never used in the Type C and later drills. What's new is that someone at the Millers Falls factory took the time and trouble to use a spot-facing tool to face off the inside of the Type D's frame to provide a bearing against which the second pinion rides and then machined a new main-handle stud with an extension on which the second pinion turns. That stud has a groove at the end to retain a C-clip; and the C-clip rides in a recess machined into the inboard end of the second pinion. The "hidden" feature of the C-clip prevents it from falling off and letting the second pinion ride too close to the centerline of the main gear, which could cause the second pinion to bind. This was all well thought out and well executed. The only problem is that the threads of the new stud don't fit very tightly in the tapped hole in the frame. The final second-pinion design used in the Type C drills uses a longer main-handle stud which passes clear through the pinion into a hole bored in the first frame crossmember, thereby increasing the stability of the main handle mount.

The present drill therefore represents an example of on-the-fly development of a new product at the Millers Falls Company - they made this drill in order to try out a new feature of the No.2 drill., using old stock parts. Clearly they never intended to retain the boss that once held the LRRCW assembly on the castings for their new-style two-pinion drills !

Close examination reveals that the frame is that of a Type D drill (the main gear runs on a steel shaft inserted into the frame rather than on an integral shaft).

On the far left one can barely see the C-clip that retains the second pinion on the main-handle stud extension. Also, the steel insert can be seen protruding from the central boss of the frame. This was a new feature of Type Post-E and later drills. The inset at left shows the spot-faced surface against which the second pinion bears. This machining was done similarly to the finishing of the frame for the main pinion.

The image at far left shows the pinion components taken out of the drill, which was easy to do, as the two cross-pins were not peened in place, nor were they severely distorted by heavy use.

The image at right shows the first step in the sequence of assembly of the second pinion. The stud is first threaded into the frame far enough to allow the C-clip to be inserted, and then the stud is backed out to a position where the pinion has a good running clearance. Lastly, it is pinned to the frame, which sets the running clearances "forever."

The two images at bottom show how well the C-clip is hidden inside the recess machined into the smaller end of the second pinion. In the right-hand image the stud is now pinned. The "production" Type D drills' cross-bars were made with a boss in the center to acommodate an extended pinion shaft, which made the main handle much steadier. This drill's main handle wobbles along with the pinion, because it isn't possible to make the stud a tight fit in the hole tapped into the frame and still assemble the pinion onto the main-handle stud.

In the end, this particular drill was quite unsuccessful because of the wobbly handle and because the meshing between the main gear and the drive pinion is quite sloppy. That was what the original LRRCW mechanism was so good for adjusting ! There is also a chance that the main gear has been replaced, as the wear patterns on the drive pinion's teeth do not align with the teeth of the main gear. As seen at left, the worn spots on the brass stud filling the hole where the LRRCW used to fit also fail to align with the rim of the main gear. On top of all that negative evidence, the main gear fits too tightly on its shaft, and so comfortable rotation of the crank is difficult.