Excellent Mantis Build Video by Brian Gray!

Brian Gray made this wonderful video of his build of the Mantis clock from cutting to assembly to fully working clock.  He sent us this link, plus some very nice compliments.  Thank you, Brian!

Clayton writes:

Wow!  This is an amazing video, Brian.  You've done an excellent job constructing your Mantis wooden clock build, but you've also done a great job showing how you did it.  You have an amazing workshop with so many excellent tools.  I was drooling!  Your shop makes mine look pretty meager.  Beautifully done, Brian.  You have shown the way these projects are approached by a true craftsman.  I'll certainly be referring this video to other Mantis builders.  Well Done!  Aloha.  Clayton

 Brian answers:

Thank you Clayton! It's been such a pleasure to put together a few of your clock designs, with more coming! I've been a machinist and woodworker for more than a few decades now. But for some reason, clocks have put a huge spark into my inspiration like no other projects in the past. Thank you very for taking the effort to make your plans available. I'm sure that creating an accurate set of plans is much more work than the clock itself, so thank you!


Perfect Involute Tooth Forms?

Interesting question from a builder:

I'm new to wood clocks, but have some mechanical engineering experience. I see that the tooth profiles on the pinions are nothing like those on the wheels they drive (and neither look like involute teeth). 

Why the difference in tooth profiles? It seems to me that the two ought to be the same. To add to the question, it seems to me the quasi-trapezoidal teeth on the driven wheels would be easier to cut accurately, suggesting the pinion teeth should be similar. What do you say?


Aloha John, it is nice to hear from you.

Your engineering experience has taught you right.  It has taught you about high speed gearing at its finest.  

Thing is...clocks don't move fast so that level of perfection is not required.

As a matter of fact, in my own experiments, it's difficult to notice any difference at all with various tooth forms.

I discuss this at length in my book, Practical Guide.

Take a look at the various tooth forms that I use in my designs.  You'll see straight sided, involute, "random", rounded, and none of them seem to perform much better than any other.

You can make high speed, "perfectly" engineered teeth if you like, but do some experiments on your own and I think you'll convince yourself that pretty much any tooth form works well at low speeds.

The old tymers used to cut triangular tooth forms.  Worked fine for them.  Hacked them out with adz and axes.

Take a look at the teeth on this old clock on the cover of the National Association of Watch and Clock Collectors (NAWCC) journal.  Here is a perfectly fine running clock with possibly the poorest choice of tooth form available...triangles.  Ha!  

And yet................it has been working for centuries.

So, my advice is to make whatever tooth form strikes your fancy and compare it against the "perfect" involute tooth forms and see how much difference it makes in the running of your clock.

Enjoy!  Aloha.  Clayton


Kinetic Sculpture and Clock Escapement Escapades

Escapements are fascinating.  Escapements add interest and movement to a clockworks since the escapement is the most active part of any clock.  And there are such a variety of ways that people have invented to allow the catch-and-release of the power that is being transmitted through a clock's train of gears.  But sometimes we don't need to build an entire clock to appreciate the movement of an escapement.  Escapements can be kinetic sculptures in themselves, and especially fun when they are anthropomorphized, or made to represent some beast.  Here are a couple of examples.

In this first short video, called "Tasty Fingers", the creature, with its teeth bared, is trying to take a bite from each of the fingers as they come around.  But the creature misses every time, which causes his hat to raise in surprise.  He is thinking, "Maybe the next finger will be the tasty one."

This is a video of the "Sipping Flowers" escapement in which a bird is sitting balanced atop a flower that is rocking with the pendulum.  And each time the flower rocks, the bird sticks his beak into the other flower (the escape wheel) to take a sip.

A wide variety of interesting escapements can be seen throughout the clock and kinetic sculpture  plans shown on my main page.  Compare the escapement of Solaris with that of Simplicity or Bird of Paradise or Harmonic Oscillator.  They are all so different and wonderful.


Sometimes Reality Doesn't Cooperate: The Monotonous Pi Clock

Not all clock plans make it for sale on my website.  This is the story of Pi.

Above:  Monotonous Pi 3D Renderings made from my dxfs
by my friend, Oleg in Russia

Below:  Pi, actually built by me, in motion below:

The Monotonous Pi is a kinetic sculpture posing as a clock. It has all the parts of both a clock and a kinetic sculpture. That huge circular pendulum has a very slow forward and back oscillation of approximately 38 beats a minute. Monotonous Pi has its roots in the Medieval 1300’s when the verge and foliot clocks were the techie’s state of the art timepieces. They weren’t very accurate. They could be off twenty minutes a day…plus or minus. That’s a pretty huge possible error spread, and that error rate in timekeeping, with only slight improvements, continued until the late 1600’s when the seconds pendulum was introduced by Galileo and others - like Christiaan Huygens (who, in my opinion, never gets enough credit). But not all verge and folio clocks had such problems with accuracy. Christiaan Huygens (1629-1695) had a suggestion that I’ve incorporated into all of my verge and folio clock designs (except Monotonous Pi), and they are actually quite accurate timekeepers. Huygens recommended a return spring on the verge to increase the clock’s accuracy. My designs, other than Pi, have just such a return spring which is created by the spread of the cord from which the verge and foliot is suspended. Most verge and foliots in those early days were suspended by a single strand of silk. By changing over to a loop of cord we can add that return spring advantage to our verge and foliot clocks that Huygens suggested, and this simple improvement increases their accuracy dramatically. You can see that loop of cord suspending the verge and foliot in my Medieval Rack, Holologium, and Wee Willie designs. But…Monotonous Pi is not one with a looped suspension cord or return spring, so its accuracy is very similar to the workings of those early Medieval clocks - which is not very good…but sometimes it’s right! However, on the other hand, as a kinetic sculpture the Monotonous Pi is excellent! Pi is a visual delight. It is lovely to watch Pi’s slow oscillating movement forward and back. And it does try so hard to keep good time, even though it’s not very good at it. Still…Monotonous Pi is one of my favorite sculptures. Pi is truly a delight to watch.

Aloha, Clayton


NEW! The Mantis Clock


Mantis by Clayton Boyer

Mantis has a large, slow, two second beat compound balance pendulum.  The pendulum on Mantis is about 46" (117cm) making it actually longer than a regular straight, hanging seconds pendulum, which are usually around 42" (107cm).   However to get a straight, hanging pendulum to tick at a two second beat, that pendulum would have to be over thirteen feet long.  Because Mantis uses a compound balance pendulum, we were able to create not only a dramatically shorter pendulum, but one with an artistic flare that beautifully accents this clock.

Mantis has a special escapement that allows for a very large and dramatic pendulum arc.  With its pendulum swinging with about forty degrees of arc, it makes Mantis as much a kinetic sculpture as it is a clock. The way the Mantis escapement is designed helps modulate its tone and creates a slow, gentle "tick" with each contact with an escape wheel tooth.  The slow swing and gentle sound of the pendulum is relaxing and mesmerizing, and the movement is a delight to view.

Mantis by Clayton Boyer

Hiding behind the mobile crescent at the right side of the dial ring is a motorized remontoir making daily rewinding of this beautiful sculpture unnecessary. The clock is powered by a weighted motor arm that automatically rewinds the clock.  The amount of drive weight is adjustable by simply changing the amount hanging from the cord on the right of the clock.  The difficult part for me was determining what to hang there.  There are so many beautiful options.  I tried various rocks (which looked pretty nice), glass spheres, a painted fishing weight, and finally settled on the clean look of copper tube.  That tube weighs 3.6oz (102gm), and to avoid over stressing the motor, the amount of added weight drive should be 8oz (227gm) or less.  The rewinding of the remontoir motor arm is powered by an onboard nine volt battery which will keep the clock running for about three to four months.

Mantis has movement throughout its design - from the massive swing of the pendulum, to the remontoir motor arm actuating the bobblehead and crescent that accent Mantis' "broken" dial ring.  The Organic clock design also has a "broken" dial, however that design is mainly aesthetic.  The dial ring of the Mantis is "broken" for a different reason - which is to allow the viewer a better view of the internal workings of this sculpture. 

Mantis was named because of the similarities between the antennae of a praying mantis and the upper part of the Mantis' double split pendulum.  As it happened, the day before the Mantis was completed we were  surprised to see that the Mantis clock had been visited by its namesake, a praying mantis. Shown going for a ride on the bobblehead in the picture below.  The praying mantis spent the night hanging out on the bobblehead, however I still needed to add the decorative brass screws, so I moved him/her to the nearest rosebush.  Obviously, such serendipity must equate, in some way, to a celebrity endorsement!

A Mantis on Mantis
Enjoy, Clayton Boyer


Beautiful Video on Making a Wooden Clock by Rasim Ramadan


"A Clock from the Fairy Tales"

Excellent and beautifully made video by builder Rasim Ramadan showing his Organic Clock build. 

Enjoy!  Clayton


Troubleshooting the Dial Train when the clock runs well but the hands are not turning correctly

Modern Times Clock
(just some eye candy unrelated to this post)

Berry writes:  I have everything completed now on the clock but having issues (I bet you hate letters like this). The motor drives the Center Wheel just fine. The Third Wheel and Escape Wheel and Pallet chug along day and night. It looks great. Unfortunately the Minute and Hour hands don't keep the time. I marked the Center Arbor Tube and Hour Arbor Tube with a spot of ink at the top. After one hour they were at the 9 o'clock position. Fifteen minutes later they're both back at 12.

I've no idea if you can help, but I'm hoping you can.

Best wishes - stay healthy, Berry

Aloha Berry, if I understand correctly, it sounds like something is slipping or some glue joint may have come apart.

Here are some of the places that slippage may occur in the dial train of these wonderful mechanisms....

Check to make sure that the center wheel tube is pressed tightly inside the center wheel.  That tube should travel with the center wheel and make one revolution every 60 minutes.  

To that tube is added the cannon pinion and its tube.  The cannon is held to the center wheel tube by the leather plug system that allows for synchronous movement of the minute and hour hands.  The minute hand is attached to the other end of the tube that is tight inside the cannon.  Make sure that the tube is tight inside the cannon and minute hand and they are not slipping.

The clock will run like that and show the minutes, but we need to also see what hour it is, so take off the minute hand from the cannon tube and slide the intermediate wheel onto its rod.  The cannon can now drive the intermediate wheel.  The intermediate wheel has glued to it a pinion.  Make sure that glue joint between the intermediate wheel and it pinion is tight.  

The intermediate pinion drives the hour wheel.  The hour wheel has a tube pressed tightly into its center.  Make sure that tube in the hour wheel is not slipping.  On the other end of that hour tube the hour hand is pressed on tightly.  Check to be sure that hand it tight to the hour tube as well.  Once you have slid the hour wheel/tube/hand assembly onto the cannon/tube assembly then you can press on the minute hand.  The minute hand should be tight to the tube.

Somewhere in that system from center wheel to minute hand, something is slipping...OR...

OR, it may not be slipping at all, possibly just the opposite.  

There is a possibility that the three tubes are binding somewhere and not running freely with each other.  The center wheel tube, and the cannon's minute tube and the hour tube must all be able to turn smoothly and easily on each other, and the center wheel tube needs to turn freely on the center wheel arbor.

If, for example, you forgot to put the leather plug in the cannon pinion and screwed the set screw directly into the center wheel tube then that tube will be dented and it will not move freely on the center wheel arbor.  That dent will cause the tube to stick to the rod and not move freely.

Sometimes tubes get dented or bent in other ways and will not turn freely on the rod or tube they mate with.  Test all tubes for free motion.

Sometimes after the rod or tube has been newly cut there are residual barbs and metal fragments on their ends that need to be cleaned up and removed.  Polishing the arbors and cleaning up the cut ends of the rods and tubes helps this tremendously.

All of the rods and various tubes must run easily on their mating rod or tube.  

Hopefully this gets your clock running nicely.  If not, send me a video showing what's happening and I can probably make a better diagnosis.

Enjoy! and send pix when you get your project completed.

Aloha.  Clayton