Almost all pendulums are harmonic oscillators, but not all harmonic oscillators are pendulums. This beautiful Harmonic Oscillator uses a suspension spring, instead of gravity, as its restorative force. Aaron Dodd Crane patented this type of system in 1841. The H.O. is my interpretation of his amazing genius. The H.O. gently and quietly ticks once every thirty seconds, which makes it an incredibly easy clock to live with. The H.O. is quickly becoming my All Time Favorite design (watch out Number Six!).

The H.O. stands 74" (1.88m) tall, which put the clock's hands comfortably at eye level. The clock, as shown, will run three and a half days on a wind. With doubling pulleys on the weights, it will run a week on a wind. In this picture you can see the "bobble" (bobette?) that we added to the bottom of the suspension spring below the bob. That's optional, of course, but I think it adds something to the symmetry. My artist friend, Forrest, did all of the beautiful copper accent work on this clock and just wait until you see his interpretation of this wonderful mechanism (see link below)!

Look at that simple mechanism! The H.O. has only two wheels and a single pinion in her going train, and two wheels in the motion train - those are the wheels that move the hour hand. That's all! The escape wheel also acts as the arbor driving the minute hand, and the slow, gently revolving copper sphere bob allows for a mesmerizing and relaxing movement twisting and untwisting the suspension spring.

Here you can see, to the right and in front, the pallets and cam. The lower pallet is in contact with the escape wheel, while the upper pallet is resting on the cam. Thirty seconds from now, that will be reversed. In the background on the right is the crutch that connects to the suspension spring via a zig-zag wire connector. It is the power of the escape wheel, transmitted through the pallets to the crutch to the suspension spring that keeps the H.O.'s bob sweetly gliding along.

Here's the H.O. in action (if you can't see the video, click here to see her on YouTube):

My friend Forrest built this amazing version of my Harmonic Oscillator: Forrest's Harmonic Oscillator Clock

To see more pictures of the Harmonic Oscillator clock, you can visit the Harmonic Oscillator Flickr Pool. More pictures will be added as builders submit them.

Harmonic Oscillator plans are available in TWO different formats. Please choose only one option:

The price of the paper plan delivered by mail is $50.00 plus shipping. If you would like to purchase Harmonic Oscillator paper plans by USPS mail (our usual method), click here:

If you would like to purchase electronic plans in dxf format and receive them via email, you must:

1. Have a CAD program that can read dxf's.

2. Have a valid email address that can receive a 5 MB attachment. Add moalanikai@yahoo.com to your safe senders list so we don't end up in your spam filter.