Turn an Open-Backed Clock
Make your marks
A skeleton clock is a clock in which you can see all of the inner gears, wheels and springs inside the movement. This is a fun project to make, and it can easily be made by a novice wood turner.
I ordered the skeleton clock movement from Turners Retreat in the UK. I have searched the web for retail locations in North America but have not found any, though some can be found on eBay. The clock movement I bought cost twenty pounds (roughly $34 Cdn.).
The dimensions I’ll discuss in this article are for the specific skeleton clock kit I bought. You may have to adjust the dimensions of your project to suit the kit you purchase.
The wood portion of this clock consists of two circular rims, a base, column support and a top finial.
I used tigerwood for this clock, but I only had 4/4 material. I glued two pieces together to form the 1-1/2″-thick skeleton inner clock ring. By using 6/4 material you will have a more consistent-looking grain.
Mark the center of the wood, and with a compass draw a 6-1/2″ diameter circle to locate the outer edge of the inner clock ring. On a piece of 4/4 wood, draw a 10″ diameter circle to mark the outside of the outer clock ring and a 7-1/2″ diameter circle for the inner edge of the outer clock ring.
Draw a 5″ diameter circle on a third piece of wood that will be the clock base. Use 4/4 material for this piece. This base piece will get turned down to about 4-3/4″ in diameter shortly.
Purchase your skeleton movement first, then build the parts of the clock to accept the movement.
Clear and accurate layout will help once you get to the lathe and start turning.
A Centered Hole
Boring a hole in the center of the parts will allow you to use a chuck to secure your workpiece to the lathe.
When you band saw the waste from the outer edge of the workpiece, leave a small amount of material beyond the marked line, then turn to the line.
Towards the Center
Gillie uses a dedicated boring device to ensure the holes are bored plumb with the workpiece. These holes will accept the tenons on the ends of the finial and support column.
Once the outer surface of the inner clock ring is complete, and the two holes have been drilled, start to turn the inner diameter of this workpiece to exact dimension, so the clock movement sits in it properly.
Outer Clock Ring
Here Gillie turns the inside diameter of the outer clock ring.
Bore the Base
Drill a 1/2" diameter hole in the center of the clock base. This hole will accept the tenon on the support column.
Finish on the Lathe
Gillie sands the outer edges of the parts and applies a finish to the surface before removing it from the lathe.
Turn the Finial
Gillie has turned a 1/2" diameter tenon on the end of the finial and roughed out the shape of the part (top photo) before trimming the waste off one end, rotating the workpiece, and chucking it in the lathe to finish turning its shape (bottom photo).
The nearly completed support column. Once off the lathe, the waste on both ends can be cut from the workpiece.
Time to turn
To be able to mount the wood to a lathe chuck, you will need to drill a hole in the center of all three of these parts. Drill these holes with your drill press now.
Cut the wood for the outer clock ring, inner clock ring, and clock base on the band saw. Cut outside the lines, as you will true up the circle on the lathe later.
The next step is to turn these three parts to size. Start with the inner clock ring, as it’s the only part that needs to be sized very accurately. It needs to fit the skeleton clock mechanism precisely, so take your time and test fit the skeleton clock until you get it right.
Drill two 1/2″ diameter holes in opposing sides of the part. Set the lathe indexing to the number 12 and drill the first hole, then set the index to 24 and drill the second hole. I use a Robert Sorby precision drilling jig to ensure the holes are level. The holes are for the finial and bottom support column.
Turn the outer clock ring to size, and part off the middle so you are left with a ring that is 1″ wide. I sand and finish all the parts before removing them from the lathe.
Turn the clock base to shape and drill a 1/2″ diameter hole in the center to accept the support column. I use a chuck mounted on the tailstock of my lathe. Sand and apply finish before removing the part.
Select contrasting wood for the finial and support column. I selected maple and stained it black. Turn the finial to its final shape, leaving a 1/2″ diameter tenon at the base so it will fit in the top of the clock.
Turn the support column to shape, leaving a 1/2″ diameter tenon on each end so it will fit in the clock base and outer clock ring. Sand and finish both of these parts. I stained both parts black, though you can use a contrasting wood.
Assemble the support column to the base, then attach the support column to the inner clock ring with glue. Drill two screw clearance holes in the clock body at 11:00 and 5:00. These holes allow the outside clock ring to be screwed to the inner clock ring. Two plastic spacers are needed to conceal the screws. Attach the outer clock ring with screws and then attach the finial to the top of the inner clock ring.
Fit the skeleton clock into the inner clock ring, set the time and enjoy your project.