Victorian Telegraph Key and Sounder(DIY Functional Replica)

Hi, I’m Thanish, and in this project, we’re going to build a working replica of an authentic-looking Victorian-era telegraph key and sounder — all using simple and everyday materials.

For those who don't know a lot about telegraph it basically is a communication device or technology from couple centuries ago, widely used and developed during the Victorian Era by several people though initially invented by Samuel Morse.

It consists mainly of two components which we call as the Telegraph KEY/Morse Key and then the second component the Telegraph SOUNDER.

The telegraph key lets you send Morse code hence basically is an input device or sender, while the sounder is basically the receiver which makes a sound when the message is received.

While i tried finding a guide initially to make this myself, I found a problem most of them were too basic like just enough for a science demo or required special tools/machines such as a 3D printer etc while i neither had a 3d printer nor enough money to outsource it either at a shop etc.

Hence this is my guide on making one which looks authentic and works but with cheap and everyday stuff and is filled with a lot of creative ways i used to salvage a few parts here and there.

So let's get started!

1. Chipboard (generally a lot cheaper than mdf in small sizes but still strong)
2. Permanent marker
3. Old/dead 9V battery (for salvaging metal casing)
4. Old newspapers (for paper mache and surface covering)
5. Cutting knife / precision blade
6. Hardware:
7. 2x M5 screw – 20mm
8. 2x M2 screw – 25mm
9. 4x Small nails
10. 1x Regular-sized nails
11. Super Glue
12. Fevicol / PVA glue / Art & craft glue
13. Acrylic paints – gold and brown
14. Paint mixing palette (or just an old dish)
15. Wire Connectors/Terminals.
16. Magnet Wire/Insulated/Enameled Copper Wire.
17. 18650 Li-IOn Cell.
18. Small Spring from a click pen.

The first part of this project will be creating the telegraph key, which is essentially an input device for our entire telegraph system. It allows you to send messages using Morse code, which consists of dots and dashes, by pushing a lever.

Important Note Before You Begin:

Throughout this step, and indeed the entire project, please refer to the accompanying photos and diagrams for each step. They are crucial for understanding how the parts are shaped, assembled, and connected. I'll be providing dimensions, but the visuals will help immensely! All parts for the key will be cut from Chipboard.

Lets Begin!

Step 1: Preparing the Key Base

The base provides a stable platform for our telegraph key.

1. Cut the Base Pieces:
2. From your Chipboard, carefully cut two (2) identical rectangles, each measuring 13.5cm long by 7.5cm wide.
3. Apply an even layer of glue to one side of one rectangle.
4. Tip: If using craft board with a plastic coating, superglue (cyanoacrylate) often works best. For plain cardboard, MDF, or wood, standard wood glue or strong craft glue is suitable.
5. Carefully align the second rectangle on top of the glued surface, ensuring all edges match up perfectly.
6. Press them firmly together. You might want to place a heavy book on top while the glue dries to ensure a strong, flat bond.

Step 2: Creating the Key Lever Arm

The lever is the heart of the key – it's the part you'll press to make electrical contact.

1. Cut the Main Lever Sections:
2. From your Chipboard, cut two (2) identical pieces for the main lever arm.
3. Each piece should be a rectangle 10cm long by 1.5cm wide.
4. On one of the 10cm ends of each piece, create a taper: Measure and mark so this end narrows down to 1cm wide. Cut along your marks to create the taper. (Refer to the photos/diagrams to see the taper shape).
5. Just like the base, glue these two tapered lever pieces together to create a single, more rigid lever arm. Ensure they are perfectly aligned. Press firmly and allow to dry.

Step 3: Making the Thumb Pad (Key Knob)

This is the comfortable spot where you'll press down on the key.

1. Cut the Thumb Pad Circles:
2. From your Chipboard, cut two (2) circles, each with a radius of 1.5cm (which means a diameter of 3cm).
3. Glue the two circles together to make a thicker, more comfortable thumb pad.
4. Once dry, glue this laminated thumb pad to the tapered end of the lever arm, as shown in the illustration/photos.

Step 4: Constructing the Pivot Block for the Lever

This block will attach to the lever arm and house the axle (which we'll add later) allowing the lever to pivot.

Determine Piece Size & Quantity:

1. The goal here is to create a small block that will be the width of your lever arm (1.5cm) and the number of these is basically 15mm/thickness of your chipboard(in mm), for example mine was approx 3mm thick hence i needed 5 pieces stacked to get the desired thickness this is needed to provide better support or rigidity and it also makes the piece look better.
2. For this use rectangles of length 3cm and width 2cm for making the block and then as usual glue them carefully one by one.

Attach Pivot Block to Lever Arm:

1. Once you have got the block dry and ready paste it onto the lever from a distance of about 4.5cm from the non tapered end (refer illustration).

Step 5: Crafting the Pivot Supports

These supports will be mounted on the base and will hold the axle for the lever arm(pivot block), allowing it to move up and down.

For this

1. 
   
2. Shape the Supports (Rounding an End):
3. On each of the two laminated pivot supports, choose one of the 3cm ends to be the "top."
4. Carefully round this top end. You can sketch a curve first and then cut along it with a sharp craft knife, or carefully sand it into a rounded shape. Refer to the main illustration/photos for the desired shape. Both supports should have a similar rounded top.
5. (Photo: Show one support with the rounding line sketched. Photo: Show the two supports after rounding.)
6. Mark and Drill the Axle Holes:
7. On each pivot support, you need to mark the center point for the axle hole. This hole should be on the rounded end, positioned vertically in the center of the 2cm width, and at a consistent height from the flat bottom of the support. (You'll need to decide this height – it should allow the lever arm, when the axle is inserted through its pivot block, to sit at a good operating height above the base).
8. Crucially, the axle holes in both pivot supports must be at the exact same height and horizontal position so the lever arm pivots smoothly and sits level.
9. Method 1 (Precise): Measure carefully on one support to find the vertical center (1cm from either side of the 2cm width) and mark your desired height for the hole. Drill this hole. Then, temporarily clamp or tape the two supports together, perfectly aligned, and use the hole in the first support as a guide to drill through the second.
10. Method 2 (Visual alignment): Mark the hole position on both supports as accurately as possible.
11. Once marked, carefully drill a hole through each pivot support at the marked location. The hole size should be a snug fit for your chosen axle material (e.g., a small nail, a piece of stiff wire, a small machine screw).
12. (Photo: Show a support with the hole location marked. Photo: Show the process of drilling the hole, perhaps using a small hand drill or power drill carefully. Photo: Show both supports with their axle holes drilled, emphasizing alignment.)

We need to make the two necessary contacts for our telegraph that is:-

1. The "Making Contact" Point: This is our primary electrical contact that closes the circuit when the key is pressed i.e this contact will be involved in an electrical circuit in short,
2. The "Rest Position" or "Back Stop" Point: This will act as a mechanical stop so that when the lever arm returns back up it goes only till our desired rest height and not any higher and this is not involved in any electrically circuit.

Note: The terms Primary Contact and Secondary contact will be used hereafter in the whole guide hence remember that these mean only electrical contact i.e the front contacts only.

Let's do it:

1. Now we need to cut 4 squares of dimensions 1.5*1.5cm which will be the mounting piece for our contacts.
2. Then as usual stack 2 pieces and glue them together in the end we will be looking at two pieces one for each contact
3. Now we still need to place and glue the bolts/contacts (which will be 20mm M5 screws) in place but we will be doing that during drilling the other holes etc since we still need to paper mache this

This step is crucial if your chipboard has a glossy, plastic-like laminated layer on its surfaces. Removing this layer will significantly improve how well paint, glue for paper-mâché (which we'll apply later), and other finishes adhere to the board.

Important: If your craft board is already raw and matte (without a glossy surface), you can skip this step.

This is a simple step, take a knife and carefully and slowly peel of the glossy layer from either side from all the parts or pieces we cut.

Most of you diyers would know what Paper Mache is and how incredibly useful it is but for those who dont know in simple words it is a way of gluing layers of paper on to our project parts so it gives strength covers any undesirable cracks or holes etc and smoothens and provides a better surface for painting so lets do it!

Supplies:-

1. Craft Glue(PVA)
2. Bowl
3. Paint Brush or you can use even Hair Dye brush which works great.
4. Water
5. Newspaper(it works the best in my opinion)
6. Scissors

How to?

Solution Preperation:

1. This is pretty simple process take your glue and water and mix them in a ratio of 2:1 for example if you take 2 caps of glue mix it with 1 cap of water and then mix them well in the bowl
2. Now we need to take the newspaper and cut decent sized strips so the key here is the part size for example if we take the base, it is big so we will use somewhat larger strips but if it is small like the pivot joints we will use smaller strips.

Applying:

1. Now these steps apply to all of the parts;
2. Dip the brush in the solution and cover the surface of the part and the strip with reasonable amount of it.
3. Then take the strip and place it over the surface of the part and and once again on top of these apply the solution
4. Repeat the same process till all the area is covered and then leave it dry preferably overnight.

Note:If you are unable to understand or even if you i recommend to watch some videos online to get a proper understanding before you do the same.

Now for the telegraph lever to return back up we need a spring but we wont be using the regular cicular/coiled ones you see everyday but we will be making ourselves a spring made of curved metal strip.

For making this follow these steps

1. Salvaging Metal: The metal that works for this job is fairly finicky, so after testing a few, I found that the metal casing of an old 9v battery is a almost perfect supply for the metal sheet we need for constructing this springy metal strip.
2. Now using a flat head screwdriver pry off the metal casing from the battery and dont worry these 9v batteries that too used ones wont have enough energy to be able to cause anything bad but still be careful while prying open because if somehow some part snaps into air it may hurt you.
3. Once you have salvaged the casing flatten it out into a flat sheet
4. Then cut two strips of width 1cm along the longer side.
5. Once done take the two strips and as we do with everything else stack and glue them together using super glue, yes i know its not the most optimal thing to do but in my experience they are good enough to keep them together even during under stress from the lever.
6. We will be drilling the holes for mounting it to the base and lever as well as shaping it into its fuctional shape in later steps for now just let it dry and secure.

Now we will be drilling holes for passing the axles through the pivot block and supports, then we need to drill holes for the adjustment screws (2 in total) to go through the lever arm here one of it is the mechanical secondary contact and the other is the electrical secondary contact which is responsible for closing the circuit along with the primary contact also now finally we will be gluing the contacts onto the mounting square pieces we cut.

1. Axle:

Note:We will be using a nail as the axle hence make sure that the holes you make are snug but free enough for the movement of the lever arm around the nail/axle.

1. For this in total we need to drill 3 holes one through the entirety of the pivot block attached to the lever arm and the one in either side pivot supports which will be attached to the base.
2. Pivot Block: Firstly mark the centre line using the midpoint and scale and at just before the edge(refer image) using a nail and hammer or a drill if you have one drill a straight hole through it to the other side.
3. Pivot Supports: For this we will be first aligning the either ends together and at its top(refer image) mark and drill a hole through it make sure it is straight because if not this can cost the alignment.
4. Gluing the contacts:
5. Take 2x 20mm length M5 screws these will be the used as our contacts.
6. Now using super glue glue them to the dead centre of either mounting piece.
7. Let it dry.
8. Metal Spring(Strip): Drill holes on either side of the strip you can use a compass(the one used to draw circles and arcs etc) or any other sharp tool for this job(yes compass works i have got mine drilled using the same).
9. Holes for Top Rear and Front Contacts:
10. We need yet again another two contacts but this time these will be going through the lever arm ( using m2 screws) and we need to make holes for them.

Note: It is crucial that these screws are snug so we can utilize its threads to move them screw up and down and hence adjust them.

1. Firstly using a compass make a guide hole or how much ever you can go safely
2. Then screw the M2 into the guide hole and make sure it comes out of the other end.

Note:I am sorry for any discrepancies in the images but they should be enough for following the instructions i have given.

In this step as the title suggests we will be test fitting all the parts and then shaping the metal strip into a strip for this you need:

1. 4x Small Nails
2. 1x Regular sized nail
3. 2x M2 screws 25mm (we have aldready inserted these in the previous step)

Now lets get it assembled temporarily for our testing:

1. From about 2.5cm in the rear place and glue( using pva only we dont want this to be super strong since we will remove this out) the supports on either end while making sure you leave enough clearence in the middle for the pivot block to move freely you can then hammer 2 small nails from the bottom of the base to further strenghten a bit.
2. Now also shape the metal strip into a close enough shape resembling the one in the image we will be adjusting further while assembling
3. Now at a distance of 3 cm from your front contact/secondary contact(lever arm) we will be mounting our metal strip by hammering down the small nail into the lever arm (bottom side up) through the hole we made in the strip (refer illustrations/image).
4. Now pass the nail through the first pivot support then the pivot block of the lever and then through and out of the other pivot support.
5. Now place the primary contacts so that it perfectly aligns with the screws or secondary contacts on top(adjust them by unscrewing or screwing in a bit if necessary and in the front contact(electrical) leave a bit of gap so that they both are in contact only when the lever arm is pressed)
6. We are done with test fitting check on your side if everything works and then you can disassemble everything for them to be painted.

Now we will paint all the parts in the following manner

We need:

Brown Acrylic Paint

Gold Acrylic Paint

A Paint brush

A small paint mixing disc or plate.

1. Base: This is straightfoward paint it with the brown paint.
2. Everything Else: This needs a bit of mixing see in olden days they used to use metal specifically brass for making the other parts hence we will try to recreate the look
3. For this on you paint mixing disc or plate, mix your gold with a little bit of brown to get to a brassish or aged golden brown colour.
4. Then from now it is straightforward use the paint you mixed to paint all these other parts and let it dry before moving on to the next step.

We are now finished with the telegraph key! Now it's time for the final assembly.

Because you've already tested all of the parts, this phase focuses on permanently securing everything in place.

Assembly steps:

1. Assemble all components.
2. Place the lever, pivot supports, contacts, and spring in their final placements, exactly as you did during the test fit, but this add superglue to secure the pivot supports permanently.
3. Secure the metal spring.
4. Once everything is in place, hammer the final little nail through the guide hole to secure the metal spring to the lever arm.

Wire the Circuit

For the wiring i have used Insulated Copper Wire/Magnet Wire but it is not necessary and you can use regular wires of any kind and colour of your wish here is how you do it :-

1. On our front contacts both primary and secondary remove the paint around a small area until the bare metal is visible do the same to the tips of the contacts if you have painted it too, this is to make sure that we get a proper conduction.
2. We will be adding little wire connectors which will act as our terminal they come inside a plastic casing which can be removed by unscrewing both the screws entirely and then the actual metal connector will slide out which you can stick it using superglue like above(Refer Image).
3. Then, on one end of the wire remove the enamel coating which is the insulation here using a sharp knife or sandpaper then wrap it around the top contact and then route it down as you wish to the terminal connectors.
4. Cut it to an appropriate length and repeat the step for the other contact too.
5. Then scrape off the enamel/insulation on this end too and screw it into the terminal.

Basic Circuit Test.

1. To test it, connect a battery and a buzzer (or an LED and a resistor) in series, to the terminal connector acting as the switch.
2. When you press the lever, the buzzer/led should react accordingly to your morse.

Now lets Continue to the Sounder.

So firstly we will get the base done just like how we did for the key:-

1. Cut 2 rectangular pieces of length 13cm and width 8cm
2. Just like how we did with the key stack and glue them together.
3. If required use sandpaper to get uniform sides and this applies to all the parts.

This will be another rectangular piece which will hold the main components of the sounder and this piece will be placed on to the base and in turn the other components on top of this mounting piece.

For making this:-

1. Cut 2 rectangular pieces of length 8cm and and width 6cm
2. then Stack and glue them together into a single piece.

This is a more complex component to make precisely consistently hence i have broken it into multiple parts which can be glued to get our component, yes this does take a bit of time but it reduces our chance and cost of any error in comparision due to various reasons.

For this you need to get the following

We need to cut several rectangular pieces of dimensions:-

1. Cut 6 pieces of length 4 cm and width 1 cm
2. Cut 3 pieces of length 3 cm and width 1 cm
3. Cut 3 pieces of length 3.5 cm and width 1 cm
4. Cut 3 pieces of length 2.5 cm and width 1 cm

Now convert these into blocks by stacking and gluing 3 pieces of same dimension into a single piece

So that we get 2 blocks of 4cm*1cm and 1 block each for the other 3 dimensions

Using the illustration kindly paste them in order to get a shape similar to the one required.

Don't get confused with the yoke in a tesla or the one used in aircrafts this is basically the part which holds the striker piece (the metal piece which strikes to generate sound) and the return spring responsible to bring the striker back up when the electromagnet turns off.

For making this also get a spring from a click pen.

Ok follow these steps:

Firstly cut these rectangular pieces cut:-

1. 4 pieces, of length 6 cm and width 1 cm
2. 2 pieces of length 3 cm and width 1 cm
3. 2 pieces of length 1.5 cm and width 1 cm.

Then stack two pieces of same dimension into a single block

If done properly you will get 2 blocks of 6cm*1cm and then one block each for both the dimensions 3cm*1cm and 1.5 cm*1cm.

We will assembling it in the later steps.

As you may know i have gone through these steps for the telegraph key already hence kindly refer the steps 7, 8 and 12 respectively to get it done for the sounder too.

Mounting bracket:

We have already made this part just paste it onto the mounting plate as shown in the image

Once done move onto the next assembly.

Mounting Plate:

Like how we pasted the bracket onto the plate now in turn paste this mounting plate on the base leaving a gap behind a bit for the connectors/terminals to be fixed on.

Sounder Yoke assembly

Glue the blocks we cut together in the following way:

Basically use those blocks with length 6 cm for the sides and then the block of length 3 cm at the top and glue them.(refer image/illustration)

There is more to the piece glued on to the midsection

1. Firstly hammer down a small nail into it in its centre this is will be helpful for keeping the spring in place
2. Then take the spring and paste it onto the surface of the midsection(i.e block of length 1.5cm) using superglue.
3. Then Super glue it into the structure in a way that the height of the spring = to the height of this block from the top(refer image/illustration)

Once all the above is done take one piece of laminate(explained where to source and its further use in the next step(electromagnet))

We will be using it as the striker, for that

1. Pass it through the gap in the yoke into the mounting bracket and then glue one end of it to the spring properly centered
2. Now the striker rebounce mechanism should be working
3. Then at the places on the mounting bracket where the striker hits cut and paste small metal pieces from the laminates since cardboard is not sonorous. (refer image/illustration)
4. Also take another piece and past on the striker so that the length is enough for the electromagnet gets a metal to pull(Refer image).

We all know what an electromagnet is — In simple words It is basically a magnet but can be controlled and powered using electricity.

As a lot of you know there is this three main things that influence an electromagnet heavily ( do remember I am explaining in simple terms and an electromagnet as simple as it may seem has in reality a lot more complications and terms influencing it but lets keep it simple here and depth to an extent that is enough for this project).

1. The Core – This is the iron nail you would much familiar with and this basically helps with concentrating the fields to make the force more efficient and concentrated like a bar magnet.
2. The Coil – This is where the magnetic field is generated when electrical current is passed through it.
3. The Current – Usually more amount of current i.e amperes mean higher or stronger field strength but it is more complex than that but still keep this in mind so that if you feel the electromagnet you made isnt strong try changing to power source which can give higher current.

Choosing the core material and the thickness of the magnet wire for the coil:-

For the core i used I laminates which i salvaged from an old transformer which in turn were salvaged from an old dead inverter/surge protector and these transformers can be found in all kinds of devices also these laminates are make up a very good core and these are significantly better than iron nails for making electromagnets but still for some reason you are unable to get it then you can go for an iron nail and bolt but make sure it is at least 5mm in diameter and strictly made of IRON.

A tip from my side, if you are new to opening/disassembling a transformer please don't try brute force or try prying it open with a hammer and a flat head screwdriver instead watch a video first on how to and there is this simple technique that will make your life way easier.

You can also salvage the magnet wire from the same transformer too for making the coils for the electromagnet.

But which size/thickness to choose for the magnet wire, does it matter?

Yes, It matters a lot here is how

So in electricity there is something called resistance and current so if you choose a very fine thin wire it will have a lot of resistance and hence heat up faster when trying to increase current

And if you take a larger size like 1mm diametre good luck finding a power source capable enough, the resistance will be so low that it sucks a lot of power and most likely will trigger short circuit protection or if you bypass it you will fry the heck out of the power source

Hence i will recommend using ones which 0.5mm they are quite easy to coil since they are neither too thin to be fragile or too thick to be stiff also for our case they have a good enough balance of resistance for our case.

Hopefully by now you are clear with the theory and the materials to choose from and the source.

So, Let’s Build It

We need two electromagnets, hence follow these steps to complete one electromagnet then repeat the process again.

I would like to clarify one thing that 'I laminates' are the straight laminates which are named i since it looks like it.

1. Cut 5 I laminates to around 5cm length each.
2. Stack them neatly and flatten the edge where you cut if necessary.
3. Secure them together — either:
4. Thread the wire through holes in the laminates while leaving a bit of the wire free around 5-10cm for making connections(if present, for context the laminates i salvaged had holes)

or

1. Use superglue or tape to hold them together tightly along with the first winding with a free end to secure it in place and prevent it from moving and causing issues while winding the coil.
2. Start tightly winding the coil try to keep it as good possible.
3. Then once you have completed till the end start another layer on top and in total get around 3 full layers.
4. Once done take it back to the other side to make sure both the ends of the coil are on the same side also leave a bit of extra length of wire at the end, this all just makes wiring easier.
5. Then wrap it up in this order:-
6. First layer with black electrical tape.
7. Second layer with paper to make it fine since coil pattern can be seen through the wrap this makes it look clean and old school.
8. And a final wrap again with black electrical tape.

Finally, sand the ends of the coil since they are coated with enamel which is basically insulation.

We have already wired and added connectors to the telegraph key and this process will also be pretty much the same but before that:

Connect the two coils in series and strictly in series only to prevent heavy current draw.

You can add a resistor in series to the coil if you feel like the battery is overheating quickly and a lot (you would have to use batteries such as li-on 18650 for your power source and here comes another component i salvaged, i got my sanyo 18650 li-on from an old dead laptop battery you can get this dead batteries from your parents or cousins decade old laptop and no the 9v batteries cant give enough current).

Now that out of the way solder a singular wire to either ends of the coil once they are in series with or without the resistor (please refer the diagram if you have doubts).

Then Stick the connectors for these two and wire them up just like how you did for the telegraph key.

We are finally done with making this project, oof was it lengthy now lets wire it up both the sounder and the key just like you say in the thumbnail to a battery and complete the working victorian era telegraph key and sounder which we made mostly of cheap and salvaged parts

Now you can use regular wires but use thicker ones again we want the current to flow properly

1. Connect one connector of the Key to one connector of the Sounder directly with the help of the wire. (I dont think i need to say this but still unscrew the connector insert your wires and then screw it back up)
2. Then connect one seperate wire for each remaining connector that is one on the key side and one on the sounder.
3. Now the open ends you have got connect them to a battery (best to use an 18650 li-ion in my opinion).

You are done we have made such a great and pretty lengthy project successfully and this has taken me a lot of time too since i had to get all the dimensions by trial and error and also thank you if you have come till this far a like a comment on this would make me feel good.

Thank You! Happy Telegraphing.

-Thanish B Urs