New Clock Design Project

I’m starting the new project by first manufacturing the fusee mechanisms that I know will be incorporated in the design.  Fusees are conical devices which are used to wind the mainsprings.  They even out the mainspring strength over the entire length of wind to keep the power to the movement even and improve accuracy.

I always make several to save time and have extras for other projects.

The blanks will be turned into cones.

The threaded spiral is now cut into the cones.  The spiral winds the cable or chain to wind the mainspring.

The fusee wheel blank is turned the proper diameter. I’m making three at the same time.

The teeth have been cut on the wheel blanks.

The fusee wheel has to have its true center restored before mounting it on an arbor.

The fusee wheels are fit to the fusee arbors.

The clock is beginning to take shape!  The overall design has been decided and the strike and time wheel trains have been calculated.  These pix show the rough beginnings of the clock plates, pillars, and screw buttons.  The clock design I decided on will be an 8-day, fusee driven, and hour striking (w/half hour passing strike) skeleton clock.  It will incorporate a Coup Perdu (lost beat) deadbeat escapement with a large 60-tooth escape wheel.  It will also utilize a center sweep seconds hand, which is unusual for a short shelf-type clock.  Stay tuned. . .

The clock dial has been “roughed out” and is the same diameter as the clock’s upper plates.  Since this is a “skeleton” clock, most components will be minimal.

The clock dial has been “roughed out” and is the same diameter as the clock’s upper plates.  Since this is a “skeleton” clock, most components will be minimal.

The finished time and strike fusees and mainspring barrels are now planted in the plates.  Note that the fusee wheels have been “relieved” of metal in keeping with the spirit of a skeleton clock.  The time fusee also has maintaining power incorporated. 


The series of pictures below shows the sequence in the manufacture and addition of the motion works  —  the group of wheels that allows the clock’s hands to display the proper time.

In this design, the motion works drive comes through the front plate on the Time #2 arbor.  Since this wheel is turning clockwise it cannot directly mate to the center positioned minute wheel, therefore, power passes through an intermediate wheel to ensure the hands turn clockwise.  This “intermediate” wheel also has the pinion that drives the hour hand — and provides the 12:1 division between the minute and hour hands. 

TRIVIA MOMENT:  This pinion, found in most clocks,  is the only pinion in the clock world that drives a wheel —   Wheels always drive pinions! 

The arbor that you see coming through the center has nothing to do with moving the minute or hour hands.  It is the elongated escape wheel arbor that will carry the center-sweep seconds hand and passes through the hollow minute wheel pipe and doesn’t interact with the motion works.  The front and rear plates thus far have remained solid, but as soon as all the wheels have been planted, and the escapement has been included,  the wheels will be relieved of as much metal as possible and a design to symmetrically skeletonize the plates will be drawn out.   I want the action of the escapement to be clearly seen.

When making clocks I sometimes jump around and make things out of sequence to keep things interesting.  Since the seconds arbor is finished and the dial dimensions are known, I decided to make the hands next.  The pix below show them after being hand-cut out of the steel plate and after their initial filing/sanding/finishing.  After further finishing they’ll be polished and “blued.”

This is the beginnings of the escapement — the pinwheel and pallet that will make the pendulum swing so the clock can operate.