Frequently Asked Questions

All the answers below are abbreviated from my usual long-winded email answers.

In what format are your plans, and what is included? 

Included in my clock plans are full size drawings for most of the parts.  All of the major components, like the wheels, pinions, spacers, etc., are given as full size patterns.  These drawings can be cut from the plans, glued to the appropriately sized stock, and cut to the line.  This same “NO Measuring” technique applies to the metal parts used as arbors and spacers.  Just put the appropriately sized metal part next to the plans, mark and cut.

All of my clock plans come with a full set of instructions and a materials list.  Besides the separate instructions, each page also has instructions for each of the parts, and there are a couple of pages that show the completed clockworks, so you can go back and reference these to see how all the parts fit together.  There are two drawings of the front view of the clock; a full front view, and a close-up where the various parts of the clock are labeled.  Also, there is a side view of the clock that shows the layout of the parts from that view.  Oversized parts are given as measured drawings.

All of my clock plans are drawn in CAD and sent as paper patterns.  No electronic transfers. 

What skill level is required, and how long does it take to build a clock? 

As far as skill level required, I would suspect that if one has the tools necessary that skill is not as important as perseverance.  When I started building these, I had almost no skill whatsoever, but that always develops after getting a little sawdust into your lungs.  These are not difficult to build, but they do take some time.

I try to counsel the people that ask about how long it takes to build a wooden clock to remember they are creating an heirloom that will outlast themselves, and hopefully be handed down through the family for generations...each generation, of course, cussing that old coot that built the silly thing.

With that in mind, please don't hurry through the process.  Take the time to make it right, and it will last - which leads to the next reason people vary in the time it takes to make their particular clockworks - mistakes.  Mistakes take a lot of time.  I spend some of my best woodworking time making them.  I've got a whole box full of "Lessons Learned" (so that's what I've named the box).  It's not my favorite part of the shop...but it has been helpful, in its own way.

My friend, Adrian Iredale, has created a wonderful video on the process of wooden clockmaking. You can view his You Tube video by clicking on this link: "So You Want to Make a Wooden Clock"

How do you cut the teeth? 

There are many ways to cut out the wheels.  The olde tyme clockmakers used a hand saw and cut each tooth individually.  That's why, if you look at many of the old wood movements, the teeth are all a little different.

My plans are drawn in CAD and can be scanned into a computer that operates a CNC machine, however, most of us don't have one of those

Another method that most of us don't have access to is a laser cutter, but both of these methods, the CNC and laser, create Perfect Parts.  Way too perfect for my taste, and anyway, how are we to get our Recommended Daily Allowance of sawdust in the lungs?

Some people use a router, mounted to a jig, that runs along a bunch of wheels mounted in a lathe.  These wheels are indexed for the correct number of teeth needed.  I've tried that method and don't like the limited tooth profiles available to me - even though you can produce a lot of the same wheel at one time.  Great for mass production.  See Fine Woodworking January and March 1986 for Wayne Westphale's article on wooden clockmaking.  They show two methods of using a router to cut teeth on wheels.

Not being interested in mass production, I use two wonderfully slow methods to cut out my wheels and pinions.  It depends upon the type of tooth profile I want to create. 

If I want a square bottom tooth profile I will use the band saw to remove most of the waste between the teeth, and then take the wheel over to the bench top belt sander and sand the rest "to the line".  Inclination, Vortex, #6 and Mission have tooth profiles like that.

If I want a swoopy, or curvy tooth profile, I use a scroll saw to cut out the teeth being very careful to cut the bottom, concave, curve of the tooth as precisely as I can.  The top of the tooth can always be cleaned up at the bench top sander.  My Swoopy and Bird of Paradise are of this type of tooth profile.

Almost everyone that sees my clocks asks about how long it takes to cut out all those teeth (as in, "Don't you have a life?").  In reality, I spend far more time on the rest of the clock than I do cutting out the wheels and pinions.  To me they seem the easiest part.  By far, the hardest, most excruciating part for me is designing the frame to put the wheels into.

More on cutting teeth… 

Tooth profile is a huge topic, and for each individual project it is also a choice. 

When I began making wooden clockworks I had a Craftsman scrollsaw (need I say more?).  Every time I turned it on it would rattle the stuff off of shelves two rooms away.  I'm lucky to still have teeth.  So I avoided making tooth profiles that had to be cut on a scrollsaw. 

All of my early designs had teeth that are more easily cut on a band saw and then the space is expanded by sanding to the line on a 1" bench top belt sander.  Thus I went with the more flattened tooth profile.

Since I started in clockmaking with the band saw method, I actually prefer it.  I find it faster and more accurate, and when I am making a prototype of a clock and need to cut gears fast, I always go back to the square tooth profile. 

One note, however...I do always knock off that sharp little angle at the addendum of the tooth.  In other words, I round over, ever so slightly, the ends of the tooth. 

The only reason I do that is because, early on, when I was less skilled at gear making, I would occasionally make a pair that would hit at the tip of the tooth (they are NEVER supposed to do that).  And rounding over got rid of my problem.  Now I do it out of superstition more than anything else.

You can cut the teeth on #6 with a scrollsaw, or a hand saw, or whatever you'd like, but I find the band saw method works best for me.

When I drew Swoopy I started with the idea that I wanted NO straight lines in her design, which, of course, meant that the tooth profiles were to be swoopy also. 

I have just finished two new clock designs and one has the swoopy, scrollsaw teeth, and the other has the square, band saw tooth profile.  It's just a preference.  Usually small and medium wheels go pretty fast on a scrollsaw, but large wheels are better done at the band saw.  Large wheels are just too difficult to maneuver at the scrollsaw.

Sanding the inside of the wheels.

As for sanding, I do almost all the sanding of the inside of my wheel cut-outs by hand.  There are special products you can order from Woodcraft that take the place of the blade in your scroll saw.  They look great, but I've never used them. http://www.shop.com/op/~Scroll_Sanders-prod-11898348-18829012?sourceid=298

You can also just cut and fold over a piece of wet-dry sandpaper and clamp it between the arms of the scroll saw.  That I did once.  Too much set up for me though.  From then on, I just sanded by hand.  Anyway, the cut-outs aren't the important part.  That would be the teeth...For the concave surface between the teeth I try to be as accurate there as possible when I scroll saw in there.  A little touch-up with a roll of sandpaper and it's done.

Finish on the Wheels

As for finish, I was just looking around at the clocks and other kinetic art that I've built, and most don't have any finish on the wheels.  The ones that do have finish inevitably have problems running when the weather changes.  I try to avoid getting any finish on the tooth surfaces.  (Also see “Why doesn’t my clock run?” for more on Finish.)

Why doesn’t my clock run?

When I put a clock into beat and it has a good, even balanced 'tick, tock', and yet only runs for a few minutes, the first thing I do is start marking teeth and pinions.  I go through the train marking each set of gears where they have stopped together.  Then I start up the clock again and when it stops, see if any of the pairs match again.  I have lots of pencil marks on my clock wheels.

Eccentric wheels are another very common cause stopping new clocks.  Rather than using the original drawings in the plan, people use Xerox copies of clock plans, and the copy machines don't always copy true, leaving them with egg-shaped wheels. I never use copies.

When looking for what's stopping a clock, I ALWAYS start at the escape end of the train and work down.  Very little stops the weight end, but it takes very little to stop the escape end.  So, those are the three things I would check first, proper tooth mesh, out of round wheels, and internal friction.  There are, of course, a few thousand other possibilities, but those three are the most common reasons for a clock that wants to stop.

Just thought of another...Are you applying any finish between the teeth?  If you are, I have a suggestion - don't.  The application of any finish between the teeth increases internal friction of the clockworks dramatically.  Finish not only makes teeth gummy, it also takes up critical space between the teeth.  A clock that works great dry, will, many times, stop dead when finish is applied.  It's happened way too many times, and now when I finish a clock I spray it - and try to keep the spray out of the teeth and just on the faces. 

Also, poly finishes never really dry.  In the fluctuating humidity here in Hawaii I found that during very humid times the clocks sprayed with polyurethane get just gummy enough to stop the train.  I've contacted the people at MinWax about this, and having never made a wooden clockworks, they didn't have a solution.  They recommended I use their Helmsman Poly since it was designed for boats.  It gums too.  Just not as bad.  So now I avoid anything hitting between the teeth.

Staining

 Rarely do I stain anything.  The only stained mechanism I've ever built was my Mission.  I was going for the Arts and Crafts look with that dark oak finish.  Marc Tovar recommends using aniline dyes for coloring Baltic birch ply.  http://www.wooden-clockworks.com Click on his MLT-13 and in there he explains how he uses the dyes.

Depthing

Follow the Depthing instructions provided in your Instructions for every set of wheels and pinions.  Use the frame as a depthing tool.  Here's how...  Take all the wheels out of the frame, and just put back in the first two arbors and put the frame back together.  Now gently blow on the big wheel.  Does the big wheel and its pinion move easily and smoothly?  If 'no' find out why and get it to work perfectly.  If 'yes', take the frame apart and remove arbor 1 and put in arbor 3.  Now you are testing the next wheel and pinion set.  Gently blow on the big wheel.  Does it turn easily?  Do this for all the wheel/pinion sets. 

Setting the Pallets and Escape Wheel 

Now when you get to the escape wheel, put the wheel in with the pallet arbor.  When the pallets are in proper position, gently restrain the pallets with your finger on the arbor.  Now turn the escape wheel.  It should first push one of the pallets out of the way, and this will cause the other pallet to come into contact with another escape wheel tooth.  Keep turning the escape wheel and the pallets should gently rock back and forth.  If the tooth on the escape wheel misses the second pallet, you need to add some wood putty to the pallet and build it up (or make a new pallet).  If the tooth hits too soon, you need to sand some off of the pallet until the pallet gently rocks back and forth under each escape wheel tooth.  You must hold the pallet arbor though because you can be fooled into thinking the pallets are too long if gravity pulls the pallets down into the escape wheel.  In some patterns the pallets are not sitting directly above the escape wheel, so gravity wants to pull that top pallet into the wheel.

If both pallets miss the escape wheel while depthing, you should cut a new pallet with longer pallet arms.  I would not recommend putting wood putty on both pallet faces to build them up.  I think that might eventually sand down the escape wheel teeth since they would be sliding across those roughened surfaces with every tick.

Accuracy 

I get a lot of questions about accuracy of these clocks.  I find that interesting because, as you know, they are primarily kinetic art.  Just getting a piece of a tree to move all day and all night is amazing, but having it tell the correct time is nearly unbelievable. 

The accuracy of any pendulum clock depends upon the stability of the pendulum - NOT the gears (if they are cut properly).  All of my pendulums are made of wood, and wood moves with the weather, making for slight daily variations in the time. 

If you want a clock that tells the exact time, you can go to Wal*Mart and pick up one of those "Atomic Clocks" that are reset each evening by the Mothership in Fort Collins, Colorado.  To get something a little less accurate, yet more accurate than my wooden pendulums, you could replace the pendulum on any of my designs with Invar steel (or even regular steel works nearly as well), and the accuracy would go up a little.  Then you could use all kinds of compensating devices to eliminate that slight bit of error, like gridiron's or mercury - but I don't use any of that stuff, because accuracy isn't that important to me. 

I have a fellow that buys my plans and doesn't even put the hands on his clocks.  He says that when he wakes up in the morning and hears the clock ticking, it reminds him that he's still alive, and that's good enough for him.  I worry about him on very humid days.

I have one clock that's dead on accurate every day, and another clock that's dead on some days, and some days it'll be off 15 minutes.  Just depends upon the weather.

These clocks are just as accurate as the "State of the Art" clocks made during the American Revolution.  As a matter of fact, my Lolli is designed after one of these Revolutionary clocks.

How long can I expect a wooden clock to last? 

Some wooden movements that are 300 years old are still in working order today.  With some care and maintenance, these clocks should out last us and our children.  Hopefully, our clocks will be passed down through the family as heirlooms.

Half-Lap Joints 

A little secret about half laps...start with a scrap the width of the stock you'll be using for the frame and set the table saw blade just shy of the height you think it should be cut to make the half-lap joint.  That height would be just a little less than half way through the stock.  Run the scrap through the saw blade, flip it over and run through again, there will be a bit of wood left between the kerfs.  Raise the blade slightly and run the scrap through again - nibbling away that bit of wood in the center of the kerf until there's just a skin of wood left.  That's the height for the half lap.

On half laps I always cut the cross pieces first since they will be behind the upright piece, and their front edges will be seen, and then I cut them just a hair shy of the proper width.  It's always easier to sand a little off of the sides of the upright piece so it fits perfectly into the cross piece.  With this method any imperfection will show to the back of the frame.  And then if there are any gaps in the front, I just get out the filler putty and large spatula and start spreading.

Solid Wood Wheels

When making wooden wheels, I first wait for a neighbor's tree to fall down.  All of my solid wood wheels started that way.

My solid wood wheel clocks (Upsy, Behemoth, Mission, Lolli and Floating Wheel) have not had ANY problems with swelling, bowing, warping, cracking, etc.  The exception would be my Lolli - she stops if somebody sweaty walks by, but that's because of her very small (2 1/2" dia) escape wheel with way to many teeth (42) - and that's why she's not listed as one of the clocks with plans for sale.  She was a tough bird to get running properly, so I don't want to spread that much frustration around the woodworking world.  Any wooden clockworks has its frustrating moments, she was one long frustration, but now that I've gotten her running, she's one of my best - if I keep sweaty people away from her.

When I make solid wood wheels, they are all glued up and laminated from pieces, but however you choose to build your solid wood wheels I would highly recommend you use ply for the escape wheel and pallets, and at the weight end of the clock, the only place ply is truly necessary is at the click gear.  I've ripped out too many solid wood click gears to go that way again.  But besides that, the weight end of the clock is the end with the most tolerance to mistakes, improper craftsmanship, etc.  As you move toward the escape end, the tolerance levels of the mechanism decrease almost to zero.  The Escape end needs to be perfect, and still it's going to take a lot of fiddling to get the clockworks to run right.  Logically then, it follows that if your clockworks is having any trouble running, start looking for the problems from the escape end and work down. 

What is the “Frustration Quotient”?

You may determine your own personal Frustration Quotient by taking the quiz below.  This scientific test will determine if you are ready to build your own wooden clockworks.

If a person's ability to endure Frustration is in the Very Low to Low Normal range, they are not good candidates and should not even contemplate making wooden clockworks.

If one’s ability to endure Frustration falls within the Normal to High Normal range a person should just talk about making a wooden clockworks.

If they can sustain the High to Very High Frustration range, a person may actually attempt to make a wooden clockworks, but should not anticipate actually hearing it tick at any point.

Being able to tolerate Frustration beyond the Very High range is a wonderful place to begin making wooden clockworks, but out of Baltic Birch Ply only.

Beyond the Very High range one begins to enter into the Masochistic realm and needs to seek professional help - especially if one is anticipating making their own solid wood wheels. 

I am a professional - and I am here to help.

Do you have plans for the MoonPhase clock?

I get a lot of email about my MoonPhase clock.  It truly is NOT a starter clock.  That clock had to be modified so many times to get it to run correctly.  If you could see those connecting rods up close, you'd see where I had to drill those things many times before they would work right.  It was a seat-of-the-pants project that got out of control.  If you wanted to build one, I would recommend you start with just making the escapement first (the thing the pendulum is attached to) and then, once that is working properly, build just the minute wheel, and the wind wheel.  Then you'd have a working clock!!!  AND a lot of clock building experience.

The stuff to the left of the minute wheel was all added on later because I had all that extra wood over there, but if you'd just build the first three wheels on the right side, and get the basic clock working, you'd be ready to build the rest.

The most important thing to remember in clock building is that the minute hand (or in this case Minute Wheel) must go around one time per hour.  Everything else is easy.  These are 17th century technologies we are recreating today.  I used to say that this is not rocket science, but since a fellow from NASA bought a set of my plans, I can't say that any more.

Here is a little clock theory as related to my Number 6

First off, the gear ratios on the #6 are not exact for a “seconds” clock - in other words, I fudged them a little for symmetry.  But it was a sweet fudge, you’ll see what I mean.  Here's what I did...

The main purpose of a clock is to get the minute hand to go around one time per hour.  With a "seconds" pendulum beating one time per second, that would make 60 beats per minute (bpm), times 60 minutes per hour = 3600 bphour. 

The exact way to create this using all 8 leaf pinions is to have a large center wheel of 64 teeth, a middle wheel of 60 teeth, and an escape wheel of 30 teeth.  Here is it in equation form; 64/8 x 60/8 x 30 (2) = 3600    The 30 is the escape wheel and it is acted on once by each pallet per revolution, therefore the 30 x 2.  Not much symmetry in that arrangement, and, in the end, that's what I was shooting for.

To maintain symmetry I changed those numbers around a bit.  My numbers for the Number 6 are; 62/8 x 62/8 x 30 (2) = 3603.75bph. 

In other words my mechanism would be off by almost 4 beats in an hour, however about a 10th of a turn of the little nut holding the bob on the bottom of the pendulum shaft takes care of those 4 seconds - which means my #6 clock does not beat exactly one time per second.  It has to beat a little faster to make up for those extra 3.75 beats per hour required by her mechanism, so it actually beats at 1.001042 and that takes care of the additional 90 seconds in 24 hours.

Isn't theory great!?  I don't have enough confidence in a chunk of moving tree to believe it's going to keep that good of time.  I think that's why clockmakers eventually went to making their clocks out of metal, and then to quartz vibrations and then to the vibration of the nucleus of a cesium atom.  The fun is in the building, and the experimenting, and in the wonder of actually taking a tree and making it kinetic - not in the accuracy. 

I always tell people, if you want accuracy, go to Wal*Mart, plunk down your $4.98 and get an atomic clock that resets itself every evening from the Mothership in Fort Collins, Colorado, but if you want to have fun, build your own.

Book Recommendations? 

A wonderful source is a book called Modern Clock by Goodrich.  It is mainly written for metal clocks, but all the information is transferable to wooden clocks as well.  It will give you more than just a basic idea of how clocks work.  Mine is well thumbed. Click on the "Recommended Reading" link below for ordering information.