Neo-Classical Mantle Clock

I upgraded to Vetric’s Aspire CAD/CAM software because of my interest in 3D CNC carving. This mantle clock was built from free plans provided by Vectric.  I have built other items from their monthly plans and have found them to be fun and useful for learning about vector creation, component creation and tool path generation. I hope you enjoy this pictorial blog about my new clock.

Pre-finish Assembly

Here is a photo of the loosely assembled parts so you can visualize what the project is about.

Gluing Joint Bit

Many projects require gluing stock to obtain the desired width of a blank. I routinely use a glue joint bit to help with alignment and increase the surface area of a glue joint. This Freud bit is used on a router table and I have found that best results are obtained by setting the height at 1/2 the thickness of the stock plus 0.624″. It’s very important to set the fence flush with the indented cutting edge or else the joint won’t go together completely or it will suffer significant snipe at one end.

Gluing Jig

Here is a look at my gluing jig and the board edges after they went through the glue joint router bit.

CNC Carving

The front face of the clock as it’s being cut on the CNC router.

Mach3 Screen Shot

As you can see, I’m 3 hours and 46 minutes into the cut and have another 2 1/2 hours to go. I’m using a 1/16″ tapered ball nose bit for the finish cut with an 8% step over. This translates into 0.0047″ step over per pass.

Finished Cutting

Here is a look at the blanks with the individual parts held in place with tabs.

Cutting Tabs

Sometimes I use a chisel to cut through the tabs but instead I used a scroll saw for this project because I didn’t want to take a chance on splintering the wood.

Router Bit Splintering

Despite my best efforts, I did get some splintering at the cutout profile using a 1/4″ down cut spiral bit. Oh well, a little CA glue will fix this before finish sanding.

Component Parts

Here are the parts separated from the blanks ready for further processing.

Finish Sanding

I use a Dremel tool with rotary disks for much of my finish sanding on the highly detailed parts.

Gluing Sub-Assemblies

Gluing sub-assemblies for further processing. Sometimes clamps are used and sometimes weights are used as you will see in later photos.

Stationary Belt Sanding

I have several abrasive machines to help with the tedious job of rough and finish sanding. This is a combination belt / disc sander making short work of sanding end grain.

Mop Sanding

Sanding mops of 120 and 220 grits are used to remove the rough sanding ridges.

Spindle Sanding

A reciprocating spindle sander is a great tool for smoothing both internal and external curves. Here the clock insert hole parts are blended to provide a uniform cavity to accept the clock mechanism.

Staining the Parts

After finish sanding the parts, they are stained with General Finishes Pecan oil base stain.

Sub-assembly Glue Up

As I mentioned previously, sometimes clamps work best and other times weights are used when gluing parts together. I left stain off of the areas that receive glue. When possible, I prefer to stain the pieces before gluing them together because it’s easier to stain without all the nooks and crannies created by corners.

Sand Bag Gluing

A cotton bag full of sand is very useful for holding flat weights on a curved surface.

Finish Coat

Two coats of a matte clear coat finish the project.

Completed Clock

The project turned out beautiful. A quartz clock movement from Klockit completes the Neo-Classical Mantle Clock.

Brian Law’s Clock No. 24

Brian Law’s Clock #24 is a wonderfully designed wooden clock with a gravity escapement that is fascinating to watch. This was my most challenging clock to build as of May 2016 because it required metal machining and CNC tool path tiling. Tiling was required because the clock frame was longer than the bed of my CNC router table. Fortunately, Vectric’s V-Carve Pro provided a way to accomplish the task.

Mr. Law’s design called for 1/4″ shafts turned to 1/16″ at the ends which are held into the frame using Acetyl bushings. That was his answer to minimizing friction. I used stainless steel and found that it work hardened during the turning process so I limitied my cuts to less than 0.005″ per pass. Despite this tedious process, I managed to ruin one of the parts because the thin shaft bent while turning. I managed to get through it but if I ever make another #24 clock, I will make the shafts using 1/8″ stainless steel held directly in the frame without bushings. The only exception would be the spool weight bearing shaft which I would leave 1/4″ supported by ball bearings.

Tiling First Step

My CNC router table is 26 inches square but the frame was 30″ tall. In order to accomplish this cut, I removed the end support bar from my Pilot Pro CNC giving me a way to pass a long piece through the Y axis. Notice the two indexing holes near the lower left of the work piece and the same hole spacing drilled through near the upper left. These index holes allowed me to accurately position the work piece by using wooden dowels drilled into the spoil board.

Tiling Second Step

Vectric’s V-Carve Pro has a built in tiling feature making the process easy. Well, not exactly easy the first time but now that I’ve done it, it will be easier the next time. Notice that after the first tile was cut, the part was re-indexed by sliding the part along the Y axis.

Frame Parts

The frame front and back pieces successfully cut and ready to be parted from the waste.

Clock Face

In order to conserve material and give the clock face a neat look, I used a CAD program to design an octagon large enough to cut the clock face. This view shows the face after it was V-Carved and nearly cut from the blank.

Clock Parts

Clock parts machined, cut and sanded ready for assembly.

Brian Law's Clock 24

Assembled and ticking on 6 lbs. weight. This clock as designed will run about 15 hours on a wind. Click on the photo to see it in action.

Scimitar Ticker

Since I now own a CNC router, I can easily cut complex parts if I have a DXF or DWG file as a starting point. I am fascinated by wooden clocks, escapements and kinetic sculptures. 2016 marks the year that I decided to delve deeper into how these devices are designed and put together. There is a lot of information available on the Internet about these things including plans for sale so that was my starting point. I purchased a couple of plans from Clayton Boyer, his Number 6 clock and his Zinnia Kinetic Sculpture. I cut the Number 6 parts on a scroll saw and it took me a couple of months because I wasn’t trying to set any speed records, concentrating instead on accuracy. The assembly was difficult because I had no experience but the clock went together perfectly and has been ticking away for a couple of years keeping very good time. The Zinnia was cut on the CNC and the assembly was fairly easy, check my Zinnia blog for details. Along the way, I purchased software for designing and cutting gears, then found Art Fenerty’s Gearotic 2.0. Wow, amazing software that lets the user design clocks, tickers, escapements, gears, plus a bunch of other stuff and spit out DXF files to cut the parts. Just what I was hoping to find to help me achieve my goal. If you are interested, check out Art’s website Gearotic.com.
 

One fairly well documented device that I made using Gearotic 2.0 was a “ticker” called Scimitar. Art Fenerty published a YouTube video on how Scimitar is constructed and can be found here. Below are some photos of my Scimitar build, I hope you like it.

 

Scimitar Parts

My first “Ticker” project parts cut on the CNC and ready for assembly. The project is named “Scimitar” and it is a weight driven kinetic sculpture.

Scimitar Frame

A nice feature of the software is the ability to generate proper hole spacing for the various gears and escapements. This frame has many bearings and spacers installed ready for other components.

Milling the Gold Spring

Another recent shop addition was a table top milling machine. Here it’s cutting an adjustment slot in a thin strip of brass destined to become the Gold Spring in the triggering pallet.

Gold Spring in Place

The Gold Spring is attached to the pallet so it overhangs the end by an adjustable amount. Due to it’s length and flexibility, the spring releases in one direction and stops when something hits it in the other direction. The escapement is called a recoil chronometer escapement because the ratchet goes backwards slightly (recoils) when the spring receives an impulse from one direction.

Gluing Parts

Sometimes gravity works better than clamps for gluing parts together.

Scimitar Sub Assembly

Everything except the decorative pieces on the end of the arms is assembled here. Weight is added and the process of timing the device is performed. Click on the picture for a video of the sculpture in action.

Zinnia Kinetic Sculpture

In an effort to understand kinetic motion drive mechanisms, I purchased a Clayton Boyer plan titled “Zinnia”.  Dr. Boyer sells plans in two formats, DXF files for CNC machines or paper plans that can be cut on a scroll saw.  I built Clayton’s Number 6 clock a few years ago and it works very well, keeping almost perfect time.  I cut my Number 6 using a scroll saw but now that I have a CNC router, I cut Zinnia on that machine.  The DXF files needed a little CAD work prior to generating tool paths because some of the vectors were open.  This is nothing that any decent CAD program can’t handle so not to worry.  Anyone interested in Clayton’s plans, check out his website lisaboyer.com/Claytonsite/Claytonsite1.htm.

Zinnia is a kinetic sculpture that is spring driven on a single shaft that has two counter-rotating sculptures that deliver a visual moire effect. The wheels are 24″ in diameter which tax the limit of my CNC machine table.  The following photos should be of interest to people considering making a kinetic sculpture.

Small Parts

Small parts were nested based on thickness. The plans called for three different thicknesses, half, quarter and eighth inch.

Cutting the Large Wheel

The large wheels were cut from half inch thick Baltic Birch plywood using an eighth inch two flute end mill. I get good results using a speed of 32 ipm with a plunge rate of 20 ipm at 20K RPM. I used the CNC to make alignment holes, click holes and counter-bores for the bearings prior to the final profile cut. I stained the facing side prior to cutting because it was easier staining a large flat panel than staining a delicate, intricate part. A little touch-up with marking pens took care of chipping.

Screen Shot

A view of the Mach3 screen as the wheel was being cut.

Cut Nearly Complete

Here is a look at the part as the final cut is nearing completion. At my feeds and speeds, the part took about 1 hour and 20 minutes from start to finish.

Cutting the Tabs

The part is held in place using tabs connected to the waste as the cut is being made. When finished, the tabs are cut using a chisel and then cleaned up by hand sanding. This operation took longer than the CNC machine took to cut the part.

Completed Wheel

The shape of a flywheel after separating it from the waste. The sculpture is destined to be mounted on a light colored wall so the wheels were stained black.

Zinnia Mount

Fast forward to when all the parts were cut out and finished. The wall mount with the stud is shown in the photo.

Rear Wheel

Next in the stack is the rear wheel.

Motor Drive

Next comes the spring driven motor drive.

Front Wheel

The final part of the sculpture is the front wheel and cap.

 

Zinnia Displayed

Click on this picture to see a YouTube video of Zinnia in action.

Number 6 Wooden Clock

After purchasing my Excalibur 21″ scroll saw, I decided to order plans for a wooden clock from Clayton Boyer. I selected the “Number Six” clock because Clayton’s website indicated it was for beginners with no clock experience. Most of the clock components were made from Baltic Birch plywood because of it’s stability. The plans were very detailed and I muddled through the cutting process for a week or so and then fiddled with fine tuning the clock for about two months. I don’t have many photographs because this website didn’t exist at the time.

The clock has been running for a couple of years and it keeps nearly perfect time. Every now and then, the clock will stop because of the humidity level. During periods of high humidity, the wood swells enough to stop the movement, a condition that a lot of wooden clocks suffer. Nevertheless, the project was very rewarding and it’s a lot of fun watching the big escape wheel drive the pendulum. The drive weight (4.5 pounds) and pendulum are filled with lead shot for ballast. There is no finish on the clock because it would cause too much friction for the clock to run.

Clock-Components

The components of the clock have been cut and need to be sanded before assembly.

 

Clock-Test-Run

The clock was mounted to a 2×4 in my shop during the initial stages of assembly.

 

Clock-on-Wall

Closeup of the clock as it now looks mounted to our family room wall.

 

Raccoon-and-Clock

My intarsia raccoon is mounted next to the clock to provide added interest.