Back to the Future Clock Face

A neighbor asked me to help him make a 24″ diameter clock face like one seen in the movie “Back to the Future”.  He has already built a Delorean time machine from a golf cart chassis complete with blinking lights and fold up wing doors.  I hope to post photos of the car at the end of this blog when they become available.  I hope that you enjoy reading about this fun project!

Two Rail Sweep

Using a photo as a starting point, I was able to construct a clock face with Aspire software. If you look closely at the upper right hand corner of the drawing, the little squiggle represents the moulding profile of the clock face. Employing Aspire’s two rail sweep function, the circular profile was added to the outer two circles of the drawing and became the 3D portion of the clock face.

Clock with table location

I knew that holding the work piece would pose challenges and that I would have to secure the clock face to the spoil board with screws, it was necessary to know the location of my table’s T-slots and spoil board’s hold down screws. Using the layer function in Aspire, the pink outline of the table was overlayed onto the model.

Initial Placement

My neighbor gave me a 24″ diameter pine table top as a blank. I secured the outer perimeter to the spoil board using clamps to cut the inner pocket, drill holes for the second markers, carve the numbers and cut the hole for the clock hands. Using the table outline in the previous photo, I was able to drill holes for the screw hold downs necessary to cut the outer perimeter moulding once the clamps were removed.

Cutting the Recess and Detail

The machine is cutting the detail and drilling holes.

Cutting Progress

The clamps were removed from the outer perimeter and the blank was secured to the spoil board with screws in order to cut the outside moulding.

Cutting the Perimeter

A closer look at the outer 3D moulding profile as it’s being formed.

Cut Completed

The final profile cut separated the bull nose waste from the blank. It was fragile and cracked but it was held in place with tabs so it wouldn’t become a projectile.

BTF Clock

The completed clock face ready for my neighbor to do the final finishing.

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.

Recipe Box

I was fascinated with Michael Tyler’s Paradise Box project on Vectric’s website so I decided to use his design and customize it for my wife Marilyn. Michael’s plans were modified to account for thinner stock and the sides were custom carved and given a gentle arc. Additional V-carving was done on the inside lid to give it a personal touch. I’ve attached a video to the first image showing the CNC machine in operation because a lot of people have no idea what a CNC router looks like. I am very pleased with the finished piece and I’m certain that the recipe box will become a family heirloom.

 

CNC Routing

After the design was modified, tool paths were generated and the CNC router went to work. Here we see the back panel being cut out after the decorative V-carving was completed. Click on the picture to view it in action.

One Panel Completed

After the V-carving and cut out operations were completed, the panel is ready to be un-clamped from the machine bed.

Holding Tabs

Tabs are programmed into the cutout tool path to keep the part from getting damaged when the panel is cut through. Clamps on the waste side of the cutout hold everything secure.

Cutting the Tabs

The panel is separated from the waste by cutting the tabs with a chisel. The tab remnants were sanded flush using a stationary belt sander.

Panel and Waste

Here is a look at the panel and the waste after the two were separated.

Mortise Cleanup

The corners of the hinge mortise had to be squared by hand because the router bits are round and therefore leave radiused internal corners.

Inside Lid - First Attempt

The inside of the top was carved with a flower design and a custom inscription. Oh no… I misspelled “Recipe”. I didn’t want to re-cut the entire panel so I milled off the text and re-cut the text in the pocket.

The Fix

Here is a look at the fix to my misspelling. There is a singular-plural syntax error in the phrase but I decided not to worry about it.

Finish Sanding

All the panels making up the box required sanding to remove burrs left by the routing processes.

Detail Refinement

The intricate V-carved top panel receives a little TLC with a dental pick.

Parts Ready for Assembly

Here is a look at the part layout before gluing.

Box Glue Up

Glue was applied and the box was assembled and clamped.

Testing Various Finishes

I wanted to fill the V-carving with a contrasting color but all of my attempts failed. I cut a goofed up panel into three sections for testing and after seeing the results, I decided on a clear coat instead.

Clear Coat Finish

The box was finished with 3 coats of a lacquer type spray coating.

Perspective View 1

A closed lid view of the finished recipe box.

Perspective View 2

An open lid view of the finished recipe box showing the divider in place.

Front View

The front view of the finished recipe box. A chain was added to keep the lid from opening too far.

Spinosaurus

Our great nephew Rylind suffered a vicious dog attack recently so he is home recuperating. Like most 5 year olds, he is fascinated with dinosaurs so we wanted to provide something for him to do while recovering. The CNC router came to mind because I know of a website www.makecnc.com that has hundreds, maybe thousands of models that can be cut and assembled. A dinosaur search uncovered the “Spinosaurus”, a 31 piece project perfect for his age. The project was brought into Vectric’s V-Carve Pro and after a little work assigning dog bone fillets (hows that for irony) to the inside assembly vectors, the tool paths were generated and the job was completed in less than 1/2 hour. I used a 1/16″ bit running at 22000 RPM fed at 32 IPM with a pass depth of 0.06″. I guessed at the feed and speed and they were spot on. The following photos tell the story of how it was cut. We sincerely hope that Rylind likes the gift and that it helps him in his recovery.

Cutting the Puzzle

The Spinosaurus parts were cut from 1/8″ plywood. Because this thin material doesn’t lay uniformly flat, the Z axis was zeroed using the table surface instead of the top of the plywood. The cutout tool path was set to the exact thickness of the plywood and it cut perfectly.


Separating the Pieces

After the sheet was cut, it was sanded on both sides and the parts were removed by cutting the tabs with a very fine pointed knife.


Ready for Assembly

Here is a look at the parts before testing the assembly instructions.


Completed Spinosaurus 1

I’m impressed with the quality of the part fit. The model is free standing with no glue.


Completed Spinosaurus 2

A closer look at the completed Spinosaurus model (oops, the tail is on upside down). If Rylind’s parents provide a photo of him after he assembles it, I will post it below.


Rylind Opening Package

Rylind shows off the contents of a package he received in the mail. I think he likes it!


Rylind Assembling the Puzzle

It didn’t take long for Rylind to put the puzzle together. This guy is really concentrating on the assembly. Unlike me, he even put the tail on correctly!


Thumbs Up

This photo sums it up! His mom said that Rylind will dismantle the puzzle and re-assemble it with glue. Good job Rylind!

Memorial Bench Repair

A neighbor and active member of Daniel Boone Conservation League commissioned a replacement back for a memorial bench on the club grounds. The original bench back appeared to have been laser engraved but suffered severe weathering to make it unreadable. A V-Carved back was selected for the replacement because even if it becomes weathered, it will still be readable.

Shellac Coat

A 2×12 Douglas Fir board was milled to 1″ thick and two coats of dewaxed shellac were applied before carving.


CNC Setup

The bench back was longer than the bed of my CNC router so shims were used to elevate the work above the Y axis machine components.


V-Carving Bench Back

The design was completed using Vectric’s V-Carve Pro software and the back was carved in three separate operations.


Jerry Holding Carved Back

Jerry poses with the completed carving. The letters and graphics were filled with black ink and HVLP sprayed with 3 coats of spar varnish.


Existing Bench

Here is a look at the bench that had weathered.


Removing Rain Cap

Jerry removing the rain cap from the old wood.


Support Beams

The stone sides have embedded 2x4s that support the bench back.


Attaching the New Back

Mark attaches the new back to the 2x4s using outdoor rated hardware. The rain cap was then put back in place.


Completed Repair

A look at the new bench back. Hopefully the back will last several years before needing replacement.

Dutch Clock

As I gain more experience with the CNC router, I am trying different projects both as a learning tool as well as making interesting items. This blog details some of the steps in the manufacture of a Dutch clock mimicking the style of Tole painting. I downloaded the free project from Vectric’s website and modified some of the vectors at the bottom of the clock to include the names of the recepients, my niece and her husband. The clock was their wedding gift and the date was carved below their names. If you are interested in the actual project instructions, they can be found here.

Routing the Clock

Both the top and bottom pieces were CNC routed using the plans and tool paths provided by Vectric.


Gluing the Clock Components

The clock is 3 dimensional consisting of front and back pieces. Here they are aligned and glued to each other. The holes in the pieces are dimensioned for an exact fit of a clock insert.


Detailing the Clock

The clock was made of select kiln dried pine so the router V bit left some fuzzies that required removal with a dental pick.


Spindle Sanding

Spindle sanding the concave curves of the clock.


Drum Sanding

Some contours were better sanded on small bench lathe using a soft drum sander.


Applying the Finish

I used a slightly modified finishing technique from that described in Vectric’s project instruction sheet.


Dutch Clock

The completed clock ready for delivery to the newlyweds.