Introduction: Reproduction Regulator Clock

This instructable

This instructable shows you how to make a reproduction regulator clock using an old clock case and three quartz movements.

I have used an old English 12" (300mm) Dial clock case from Ebay but any case can be used as long as three quartz movements can fit inside it's dial.

There are two versions of this clock. A very simple design having 3 independent movements that requires no wiring or electronics and a high tech version that has all dials synchronised to an external or internal "Atomic" Master Clock that needs wiring and electronics.

This clock can be stand alone or be part of a Master Clock system as a slave. I have added various circuit designs that should be able to interface with most types of Master Clocks.

This clock can be driven by my DCF77 Master Clock and my LCD Master Clock Instructables.

Note fig.2 was taken when testing the clock so the hands are in incorrect positions relative to each other.

About Regulator Clocks

Regulator Clocks had unusual dials, with a large minute hand and smaller seconds and hour hands and were used in observatories around the world. This dial layout is designed to minimise mistakes when reading the time. Original versions of these clocks were very accurate are relatively rare and often expensive.

Dial Designs

The dials on these clocks all seem to have different designs with some starting at 0 or ending in 60, some with roman numerals and some with Arabic numerals or a mixture of both.


Dial 1

Dial 2

Dial 3

I chose my favourite parts from each dial type (Arabic minutes ending on 60, Arabic seconds ending on 60 and Arabic 24 hour ending in 24. My preferred layout was then drawn up in TurboCAD. Any other vectored drawing package can be used.

Two Instructables enclosed

Instructable 1

Needs no knowledge of electronics or modifying of quartz movements but requires basic craft/fabricating skills with wood and metal along with some basic CAD skills.

Instructable 2

Needs some basic electronic wiring, soldering and prototyping construction skills and requires simple modification of quartz clock movements. It also requires basic craft/fabricating skills with wood and metal along with some basic CAD skills.

Step 1: Case

The case above shows the high tech version with Master clock control and manual switches and wiring to the quartz clock modules. The low tech simple version has no wiring or mods to the quartz clocks. If direct connection to a Arduino or microcontroller is required then most of the wiring could also be done away with. See schematic section.

The case can be anything you want from an old school dial clock, a longcase (grandfather clock), a modern garden clock or any custom design you like.

The main thing is that 3 quartz clock movements need to fit across the dial. A 12" or 300mm dial is a great size as you get plenty of space and even the smaller hour and seconds dials are easy to read.

There are loads of old clock cases for sale on Ebay. I have found some with just the round frame and no dial or bezel. My case was complete with bezel but no dial. Dials or bezels can be found on Ebay or from clock maker supplies. fig.2 shows a complete clock case with brass dial bezel and back box with just the dial missing.

The back box that came with my clock case has a nice rounded bottom and a couple of doors. If you don't have a back box then you can always make a square replacement out of matching timber/plywood or a more elaborate design as fig.3.

fig. 4

On my clock the back box is hinged to the dial surround on the left and the surround in fixed shut by two wooden pins on the right. The dial bezel is also hinged to the dial surround and is fixed shut by a catch.

On more modern clock cases the surround is fixed to the back box. These can usually be separated and hinges/catches fitted.

Step 2: Quartz Movements and Hands

This clock requires three quartz movements. The seconds movement is just a standard movement and has only the second hand attached.

The minute movement is a high torquemovement and is designed for driving longer hands.

The hour movement is a 24hrs movement and the hour hand will turn one revolution per day.

Quartz movements are available with various length spindles make sure you get spindle lengths long enough to extend through the dial. For best effect the movements are mounted on a bar behind the dial so the fixing collars cannot be seen from the outside ot the clock. No antique clocks had movements fitted with collars so to make the clock look period these have to be hidden.

When you buy movements they often come with a choice of hands. Do a Google search of clock movements and find the hand/ dial combination you prefer. I could not find the exact style of hand in the lengths I wanted so I just cut/filled hands to the size and shapes I wanted. There are a few types of clock hands and spindles so make sure if you purchase movements and hands from different suppliers they are compatible.

Step 3: Mounting the Quartz Movements

Note the dial numbering and rings are shown printed out in this stage for illustration only. The dial should be painted and dial transfer (decal) applied and lacquered over once the fixing holes have been completed.


The quartz movements are mounted on a vertical metal bar. Holes are drilled in this bar to take the spindles. The hole size will depend on your clock movement spindles. As the movements are fixed to this bar not the dial the Mounting collets are not visible once the dial is in place. This gives the impression that the movements are mechanical.


To get the hole positions on the dial and mounting bar use the paper dial template and center punch the dial on the 3 center marks. Use a nail and hammer if you don't have a punch. Remove the paper template and lay the dial over the mounting bar. Temporarily tape it in place. Drill a very small hole through the dial and mounting bar on the 3 punched marks.

Separate the dial and bar then drill out the holes to just over your spindle size. Do not drill the full size hole in one go but use 2 or 3 smaller drill bits to make the holes larger in stages. This helps you keep the holes centered and stops the drill bit tearing the dial which is quite thin sheet metal.


Shows the metal bar drilled out.

Fixing the bar to the case will vary depending on your clock case. In my case I have used a flat bar and cut two slots in the wooden frame that supports the dial. The depth of the slot will depend on the length of the clock spindles but can be adjusted with washers if required. If you do not want to cut slots in the case you can always bend the wooden bar into "L" shapes at both ends to bring the bar closer to the dial. Again spacers can be used for final adjustment. Do not drill the dial surround fixing holes at the top and bottom of the bar until the bar has been cut to fit the back box (see the step "Mounting Completed Dial & Movements").


Shows the clock modules mounted in place on the metal bar. The fixing collets are bolted to this bar not the dial.


In the finished clock the hour and second movements will need their hands close to the dial. The Minute hand should protrude further in and clear the hour and second hands and spindles. Use spacing washers between the bar and clock modules to get these gaps correct.


Shows the completed dial. I have made the dial transparent so the mounting bar and clock module fixings can be seen.

Step 4: Dial Drawing & Construction

You will have to make your own dial and the easiest way is to design it on a CAD program. A 12" dial will fit nicely on A3 paper so you may have to take it to a printer if you don't have access to one. You can print the dial in 2 halves on A4 paper and then join them together. I print out a few designs on plain paper and try them out on the clock to see which I prefer.


There are probably many ways to draw dials and many different types of software to draw it. I use TurboCAD and I start with the minute ring starting from a point in the middle of the dial. First draw a circle the actual size of the dial. This is your cutting guide for the finished dial. Then draw 2 circles centered on the middle point of the dial. These form the inner and outer edge of the minute dial ring.


Starting at the top of the dial draw a vertical line from the inner and outer minute ring. Select this line and then using "radial copy" copy this line 60 times with a 6° step angle (360°/60=6°).


The minute numbers are then added.

Choose the font and the size of numbers you require then draw a circle as before but add half the size of the numbers and a few millimeters to allow for the space between the numbers and the minute dial. You will now have the minute dial and a circle around it. Add a cross to the top of this circle. The radial copy as before with 12 copies with a step angle of 30° (360°/12=30°). You should now have the circle with 12 points for your 5 minute intervals marked out. Starting with the number 12 and selecting it's middle point place it on the top cross. Do the same with the number 5 but rotate it by 30°, the number 10 rotated by 60°, the number 15 rotated by 90° until you get to the number 55 rotated by 330°.

Draw center points for seconds and hour dials and using the same technique you used for the minute dial draw the seconds and hour dials.


Draw dial labels as required. These can be anything you want. Often these included the makers name and city/town of manufacture.

Delete all guide lines and points but leave in the 3 center points as these will be used on a paper print as a template for the dial spindle holes.

The paper template is fitted over the dial and the 3 center points are marked with a center punch or nail and hammer. Pilot holes are drilled and then these positions are also marked on the movement mounting bar see the section "mounting the quartz movements". Increase the drill size in steps until the final spindle hole size is reached on the dial and movement mounting bar.

The final design is then printed out on A3 Lazertran inkjet paper as a giant decal. The center points will allow you to position the clear decal over the three spindle holes.

The original dial is first rubbed down to remove all old paint and lettering. It is then primed and painted an off white colour (white looks terrible in an old clock case). The dial decal is then applied to the blank dial and then when dry 3 coats of acrylic varnish are sprayed over the top. This makes the decal background go clear so the off white dial can be seen with the dial lettering on top. See the instructions that come with the Lazertran paper for full details.


Hires dial image for printing

fig.6/7 TitboCAD and AutoCad drawings

Step 5: Modifying Quartz Movements (not Required for Basic Design)

The quartz crystal with integrated circuit board are not required in the high tech version and are cut out/disconnected from the drive coil pins.
The clock movement will need to be taken apart to access the electronics inside. There are many types of quartz movements but they usually have the same basic components. The coil terminals need to be isolated from the rest of the electronics and wires soldered to them so they can be driven by an external source.

fig.1 looped animation (if you can't see the animation try this link)

Quartz movements are driven by a Lavet type stepping motor. These motors requires very low current to drive them and upto three can be driven direct from an Arduino output or logic gate via a trimmer resistor. The resistor is used to adjust the current to the motors so they work without being over driven. The motor is driven by reversing the polarity to the drive coil which causes the permanent magnet toothed rotor (in red below) to turn 180°. The toothed rotor will continue to turn in the same direction each time the drive motor polarity is reversed. 2 output pins from an Arduino or logic gates are used to pulse the drive motor with 1 pin always the opposite to the other.


Start by removing the adjustment knob (not always necessary).


Carefully prise the case apart with your fingers or a plastic knife. On some cases the are 2 plastic tabs that have to be prised away to release the case.


Once the lid is removed the movement is exposed. On some movements the printed circuit board can now be accessed (fig.6) but on this movement the lower part of the case has to be pulled away as well and turned over. It may be worth taken a few pics at this stage with your mobile phone in case the small gears fall out. Note this pic already shows the new wires connected to the coil drive pins.


This shows two connections to the integrated circuit that have been cut away and the new wires soldered in place.

Once this is completed the movement is put back together by reversing the above.

Push on a second hand and test the clock by briefly connecting the wires across a 1.5v battery - the second hand should step. Briefly connect the wires to the battery again but this time reversed and the clock should step again.


Shows an alternative clock movement with the top cover removed. Slide out the PCB and cut away any tacks to the drive coil pins with a craft knife then solder wires to these pins.

To make sure there is space for the case to shut just cut a small slot in one half ot the case to allow the new wires to pass through.

Further reading

There is a nice instructable here showing quartz clock movement disassembly

Step 6: Mounting Completed Dial & Movements

fig.1 Shows the dial mounted to the wooden surround (with hinged brass bezel in place). Note the clock dial is shown white and would be off white on the real clock. The dial is screwed in place with 3 tiny self tapping screws hidden under the brass bezel.

fig.2 Shows the dial removed revealing the wooden dial board behind. Every dial surround will be different and depending on construction some of the wooden backing board will need to be cut away with a jigsaw to allow space for the hour and second clock modules.

fig.3 With dial surround semi transparent to show the vertical clock module mounting bar fixing position. This bar will need to be cut to length so it does not foul the back box and prevent the dial surround from closing. Depending on the thickness of the dial board the bar may have to be inlaid into the board to get it closer to the dial so the spindles protrude the correct distance through the dial.

fig.4 Shows the back box. The dial surround is fixed by two hinges and either a catch or wooden pins to the back box. On the original clock the back box would have housed the large mechanical movement.

fig.5 Shows a semi transparent dial surround, clock modules and mounting bar on top of the back box. The mounting bar has to be trimmed down so it fits inside the back box. The mounting holes in the bar need to be drilled once the bar has been trimmed.

fig.6 Shows the completed clock with the bar inlaid into the dial surround and in this case small cutouts in the dial surround to make space for the clock modules. Note this fig shows the high tech version with control switches and associated wiring/circuit boards. In the simple clock there is no need for any wiring or switches.

Step 7: Electronics (not Required for Basic Design)


This shows the main diagram of the clock driver circuit. This circuit converts an output from an Arduino or PIC microcontroller (only 2 pins required) or a 2 second pulse via the converter circuit and drives the 3 clock movements. Variable resistors adjust the drive current through the coils. The resistors are adjusted by observing the sound and kick of an attached second hand.

Switch SW1 flicked on and off via SW2 set to manual is used to set the second hand. SW2 turns seconds to Master driven or manual control.

Switch SW3 turns the minute and hour hands On or Off.

The zener diodes prevent any back emf from the coils damaging the drive stages.


This is a cut down version of fig.1 and has no manual setting of seconds or switching of hours and minutes but save a considerable amount of wiring.


This is a version for Arduino or PIC microcontrollers that requires 6 spare pins and saves a huge amount of wiring as the three clock movements are controlled and adjusted individually by three microcontroller output pin pairs. The output pin pairs are always opposite polarity to each other and change polarity once per second. You will of course need to write the code yourself. A very basic example from my Master Clock code quartz clock driver is shown below.

void secondsmotor (){
if (quartzmotor1 == LOW) {

quartzmotor1 = HIGH;


else quartzmotor1 = LOW; {

digitalWrite(quartz01, quartzmotor1); // set the quartz motor drive 7 pin


if (quartzmotor2 == HIGH) {

quartzmotor2 = LOW;


else quartzmotor2 = HIGH; {

digitalWrite(quartz02, quartzmotor2); // set the quartz motor drive 8 pin




If you just have a 2 second pulse from example a master Clock then use this circuit to convert it to a 1 second alternating pulse.

figs.5,6,7 & 8

Show the veroboard layouts for fig.1 and includes a switch connecting board. There are so many combinations of wiring or switches these are not shown in any great detail.

fig. 9

Shows the switches accessed behind a side door in the back box.

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