Trillium Flourish – Skeleton Clock Build
Entered into the 2023 NAWCC Crafts Competition Lancaster, PA (July 13–16)
J. Bruce Weeks entered the first clock he ever built in a national competition and won in all three categories he entered.
The National Association of Watch and Clock Collectors held their 80th annual convention in Lancaster, PA July 13 – 16, 2023. Part of the convention is the internationally renowned Crafts Competition. Entrants from around the world compete in 27 classes for awards.
Bruce entered his skeleton clock in Single Train Clocks where he received a Second-Place award, Experimental Clocks (due to use of exotic materials) and was awarded a First-Place medal. He also entered the specialized fixtures he created to build various parts of the clock in Horological Tools where he won a First-Place award.
“I am very pleased to be recognized by my peers for my efforts to build this clock to a high standard. Looking over the other competitor’s entries, the standards are indeed quite high,” said Bruce. “It has been a bucket list item for me to complete this clock since beginning design work in 2008, and then enter it in this competition. I finally achieved it with better-than-expected results.”
The National Association Of Watch and Clock Collectors (NAWCC) was formed in 1943 and “has nearly 10,000 members worldwide. The NAWCC is committed to being, “the world leader, educator, and advocate for horology and for everyone interested in timepieces and the art and science of timekeeping.” According to Merriam-Webster, Horology is the science of measuring time.
Located in Columbia, PA, the organization has a large horological museum, the largest research library, provides watch and clockmaking courses to build skills, and supports regional chapters, symposiums and the national convention. Their website is extensive, and you are invited to browse the rich horological history to be found there.
The Crafts Competition hosted at the national convention allows entrants to build their skills in any of 27 categories from dial and reverse glass painting to repairing and even building complete clocks from raw materials. Any horological pursuit is encouraged. Each category is thoroughly reviewed by three independent judges and scored for degree of complexity, finish, and fitness for purpose among several other criteria. Youth are encouraged to join as well as the NAWCC desires to keep these skill sets alive and well.
Bruce continues to operate the Talbot Clock Shop in Easton, Maryland where he services and sells antique timepieces. He specializes in difficult repairs where otherwise unavailable parts may have to be made to return the clock to use. “Many clocks that come in for repair have a story attached that makes the clock important to its owner. And I love hearing them.”
About the Trillium Flourish
Trillium Flourish is my first clock that I have built completely from scratch. It is a three themed clock in all aspects, comparing and contrasting traditional design, materials, construction and finishes with modern versions of same and tastes.
Design: Consists of three elements; 1. Traditional elements such as single train and passing bell strike, 2. Less traditional elements such as offset train and dial, 3. Combined elements of both such as the dial with traditional numeral plaques using the new design elements.
Stylism: Consists of three elements; 1. Three petaled trillium flower repeats in all components that are round or circular in nature, such as wheels, 2. The "slash" element is carried throughout in components that are flat by nature such as plates, levers, etc. 3. A minor design element is the flared end cylindrical components with a central bulge, such as some arbors and certain pillar posts.
Materials: Consists of three elements; 1. Traditional materials such as brass and steel, used in their typically found locations, 2. New materials not normally found in previous examples such as carbon fiber plates and Corian base, 3. Stainless steel used in the fasteners but not normally seen in historic examples.
Finishes: Consists of three elements; 1. Polished or gloss surfaces such as the plates, 2. Brushed surfaces such as wheels and the "slash" pillars, 3. Naturally acquired patina particularly on the bronze components.
Building the pillars for the clock
The four pillars reflect the general theme of the plates.
I built a holding fixture for the pillar blanks. They mount using the threaded fastenings which will hold the plates together. Two separate pilot holes pickup the center point on the rotary table. The point is used to align the table's Y axis, then crank the X axis over to the radius to be cut. Here the outer radius is being cut.
Changing to the other center point and resetting the mill, then cutting the inner radius. Both radii are the same, just different center points.
Two done, two to go. The pillars will be brush finished then lacquered.
After squaring up the brass stock, drilling the fastening holes.
Using the lathe to insure straight tapping. The ends were faced to length while turning a pilot collar to align the pillar with the plate, and both plates with each other (forgot to take a picture of that).
Fabricating the escapement verge
4X layout of the escapement.
Using the bench mill as a precision drill press.
Marked out for cutting.
Removing the bulk of the waste by band saw.
Ready to file finish and grain.
Notice the two end faces are to be parallel, and the top face is parallel to the two lower extremities of the verge. This is so it can be spread or drawn closer easily in a the bench vise for fine tuning escapement depth.
Using a small dapping punch to close both sides the holes for the pallet jewels slightly to make a snug fit. This is so the jewels will be held tight enough to not fall out during escapement tuning.
It also provides a small sink for the jewel cement once tuned.
Using traditional shellac to cement the ruby pallet jewels.
Building the winding clicks and maintaining power assembly
I had this main part already 80% finished back in 2009. It mounts the winding clicks and springs, and the maintaining power springs. The rachet on the OD is for the maintaining power clock so the clock continues to run while winding.
Here I'm tapping the winding click spring mounting hole.
Need three clicks as exactly the same as hand work can make them. Once one is close to shape, the second one is added and positioned relative to the first by the long pin.
Here all three clicks are being filed to matching shape.
For the click and maintaining power springs, I made a simple jig to hold four together tightly for milling away excess material.
Needing three GOOD ones, I made four do I could have a practice piece to destroy learning each next step.
From the left, the milling jig, then the resulting spring blanks with a flag at each end to be shaped after forming, the bending jig to control the radius, one partially completed spring, then the finished spring.
One click and spring in place. There will be three to match the trillium theme of the clock.
Main winding rachet getting it's three mounting holes.
Completed rachet has 13 teeth so the clicks fall one at a time in succession. That way if any one fails, there are two backups, no runaway mainspring here!
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Action of the main winding clicks. Note how the three fall in succession. Most of the working parts will be unseen inside the assembly, just the click tails and springs will be seen. Still, what you will see in action will be fascinating and satisfying.
Fabricating the lenticular trifoliate pendulum bob
I actually also did a 4X layout first to make sure I knew exactly where the crucial points were. Then did a rough layout on the 1/2" brass blank material.
Locating the exact center point, which is also the exact center of gravity.
Half-inch ball milling the rating nut thumb recesses in both sides.
Using a 1/8" mill to cut the rating nut slot.
Drilling the rating screw hole and upper pendulum rod relief.
Special fixture on the rotary table to locate the roots of the trifoliate leafs at 120° apart.
The fixture is moved the exact distance between the geometric center and the hole for the first root. Then a 1/4" roughing mill shapes one side of each of two leafs.
After relocating the bob twice more, the last two sides have been milled out here. The hole at the leaf root accepts a 1/4" dowel pin for locating the bob accurately, then after clamping it is removed for milling.
Next, the lenticular shape has the be turned. Since there is nothing solid with which to hold the bob exactly centered, I'm doing "turning in a box". First a wood block is attached to the lathe face plate.
Then a recess is turned into the face exactly the same diameter as the points of the leafs.
The "box" recess captures the bob and insures concentricity with the lathe.
A couple #4 screws hold the bob in the recess. Adding a 1/4" dowel to provide driving torque and insure the bob doesn't simply rip the bitty screws right out.
The compound set at 9.7° removed the bulk of the waste.
Then it's all hand work with a graver to smooth the shape into a lenticular surface.
I didn't show the use of the file to further smooth and develop the surface as you're not supposed to ever use a file on a lathe at risk of injury. Don't worry, I AM a professional! This shows graining with fine emery paper.
A little more work and it will be just where I need it to be.
The pendulum stick is a flat piece of CF and so requires a narrow slot into the bob which will prevent rotation of the bob while running.
Here, I got a 5/64" cutoff tool and reworked it to do that operation. I made a holder for the blade to be centered exactly on the lathe center. Cranking the longitudinal feed on the lathe while moving the cross slide 0.002" per stroke did the job. In case you're wondering, that was 45 cuts . . . per side . . .
Here the opposite side is done and the bob is flipped over to do the near side. Since the pictures are a bit out of order, you can see the finished slot in shots of the turning of the lenticular surfaces.
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Running on a test weight WITHOUT ANY OIL! Imagine in final tune and fully oiled it will take significantly less weight.
Using this test set up to determine the exact mainspring to order for it. Then I can bench test that spring's power curve to develop the shape of the fusee.
Making the motion work for the skeleton clock
Completed motion work carries two of the three themes of the clock: the trillium, and the "slash".
The minute pinion was made back in 2010, so I made up the minute pipe in the lathe and here I'm pressing them together.
Tension washer for hand setting starts with a hand made brass washer 0.020" thick.
It is domed in the dapping block . . .
. . . like this . . .
. . . and comes out looking like this. From here it was filed into the three leafed tension washer.
Making the motion cock starts with a 1/2" square brass bar. I added about an inch to each end so I could bolt it into a custom made fixture. Then just started milling away any material that didn't look like a motion cock. Here I'm rendering the step between the plate and the outer pivot location.
Then the rotary table was used to impart the curved sides with a roughing mill.
After cutting away the excess material used to hold the cock, the shape begins to "take shape." From here lots of file finishing to achieve the final shape shown in the first picture.
Building the mainspring barrel
Starting the main spring arbor. After turning the shoulder for the back barrel pivot, then turning the back plate pivot, used the graver to sharpen the corners to take out the radius left by the carbide bit.
Roughed out arbor compared to the 2X layout drawing.
Into the mill to create the winding square using the rotary table for positioning. Ultimately had to put a jack support under the free end to avoid deflection (not shown)
Forgot to take a pic of the inner hook after turning, but here I'm riveting it into the arbor after cross drilling its installation hole.
Lots of filing to take the round head down to the hook shape needed to grip the inner end of the spring.
Here's what the completed hook looks like. Need to dress up those shoulders on the pivots yet.
On to the barrel. Squaring up the ends and trimming to length
The back barrel cap is getting a shoulder to locate it before soldering.
Big part needed use of the larger propane torch to get it hot enough for the solder to flow well.
Back to the lathe to: 1. Trim off the back cap flush with the barrel sides, and: 2. Cut the groove to retain the cap. After inserting a temporary press in plug for support (and keep it round), turned a 20° back angle groove that the cap will snap into
Reversed the barrel in the lathe, indicated it into true, and bored out the back pivot hole to size and on center.
On to the cap, turning the 20° angle that will snap into the barrel groove
On to the barrel spring hook. Roughed out shape on the lathe. The small post will be riveted into the barrel.
Completed shape after much filing. Hook at the left engages the outer spring hole, lip at the left reduces lift out forces as the barrel is quite thin and I often see them pulled out after perhaps a century or two of service
Didn't get a picture of riveting process. Put a large round mandrel inside to support the hook while riveting the small post from outside. Filed the riveted post flush with the barrel OD. You'll also notice I put a bronze bush in, and also the cap as this is the working pivot.
Adding picture of the spring and arbor mounted in the barrel, ready for the cap to on.
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It's been running under its own spring power 6 hours now. Winding felt very smooth and equal effort throughout, exactly how a fusee clock should feel.
On to the dial and hands.
Cutting cheese-headed screws and washers
L-R, T-B, #10-32 main pillar screws, #5-40 secondary pillar screws, #4-40 for dial mounts and the escape clock, #2-56 maintaining spring and stop cock screws, and lots of brass washers. So far 31 screws and 23 washers. Still have 3 - #1-72 screws to make. Every part I DON'T make costs me points in the Crafts Competition next month, so I'm making as many as I possibly can.
After turning the head diameter, then the body diameter and threading the body, here is the screw being parted off the stock.
After making a simple holder (threaded scrap brass bar) I can slit the head to receive a screwdriver. If need be, I can go back to the lathe and true up the head for roughness from parting off or bring head height down for consistency.
After drilling out the center of a brass rod for a specific screw size and parting off an individual washer, I used the pot chuck to hold it so I could put a small recess in the back side. Provides a "springiness" to help lock down the screws.
The #10 washer didn't fit any of the steps in the pot chuck, so I made a temporary one to use in the three jaw. Tricky to set up, but I made it work.
Building the dial frame for the skeleton clock
Numeral plates sawn out to be hand filed to final shape.
Turning out hour pip holders.
Needing two flat sides, I built a simple mill holder. After milling one side . . .
. . . flip it over to mill the exact opposite side to the same depth.
Building the assembly fixture. 12 equally spaced holes, each will receive either a numeral plate holder or hour pip holder/holder.
Straight edge ensures numeral plates are exactly opposite each other.
Hooping the 0.032" x 0.250" brass strip for the frame. Two needed, one smaller than the other.
Protected the MDF with 700° exhaust gasket paper so soldering torch doesn't burn my shop down. Outer frame hoop in place after skarf joining the ends, inner hoop to follow.
All parts on the assembly fixture. Simple paper binder clips hold everything in place during soldering. Remove one clip and solder that element, immediately replaced the clip to ensure it stays in place, move to the next.
Completed frame ready to silver.
Blind drilling 1/8" copper plate for numeral holding pins. You can see the numeral strokes scribed in the layout bluing.
Hand sawing the bold numeral strokes.
Filing the strokes to shape.
The minor numeral strokes were made by passing #12 copper house wire through the offset dies in the bead roller. Flattened to 0.050" leaving two rounded edges, one of which will be facing the viewer.
Needed dial frame supports where the frame is not backed up by the movement's plates. Here I built a forming die from plywood and PVC drain pipe. The 3/16" brass bar . . .
. . . is formed into a nice curve . . .
. . . to be cut and hand filed into to symmetric supports.
Each support needed a screw hole for mounting. Used the mill as a precision drill press.
The copper numerals and bronze hour pips were patinated as the full on polished shine did not suit my design esthetic. Three eggs are hard boiled eight minutes (you want that grey/green look to the yolks). Placed in a Ziploc while still hot, they get smashed up, the numerals are placed on top on a small plate for 8 hours. The result is a pleasing mottled patina.
Completed and ready to install.
At last, all is in readiness.
This is where the fun begins . . .