How To Make A Metal Detector?

A metal detector is a high power safety device. The application and algorithms of a metal detector are very interesting. We will show you how to build your own metal detector. This might sound intimidating, but it is relatively easy. With the right tools and our expert guidance, you can even start your own pro company. In this article, we will cover the steps to make a metal detector using two different methods.

How to Make a Metal Detector – Multiple Methods

In this article, we will show you two ways to make a metal detector. The first one is an easy metal detector. This will need professional materials. The second one is an easier version. This will include how to make a do-it-yourself or DIY metal detector.

Method 1: The Simple Metal Detector

Do not let the name fool you here. Although it says it is simple, the process is quite tedious. The components used here are accessible. The circuit used for this is quite simple. There is not much hassle. All you need to do is follow the instructions correctly. Of course. This article may leave you wondering. You might wonder if this is really possible? Will it work? We assure you it will. One thing to keep in mind before you start is to educate yourself. A piece of surface-level information on metal detectors will not suffice. You have to dig deeper. Find out the motors, mechanisms and protocols that govern these devices. 

Step 1: Gather The Materials

We will give you a list of all the things you need. Some of the terms might be quite technical. We will try our best to simplify it. However, you need to know that making a metal detector is not child’s play. You will need a little physics and geometry to make it work. If this seems too tricky, you can try the other alternative. While you gather the materials, be careful of the product quality. Sometimes, the detector does not work because of faulty materials. These are small particles. They are readily available in any store. Avoid purchasing things online. The size and quality might differ. 

Step 2: The Layout

A layout is basically putting your action-plan onto paper. Since you are just starting, you can either make one on your own. If this is difficult, use pre-made layouts. Before you go into the practical, you have to draw a layout. This is also called a schematic. A schematic design looks like the wiring map of a house. It is a rough sketch of the device. If you have a science background, this will be a piece of cake for you. Some people change the position of the switch and battery.

You can always experiment with the layout. You cannot make a layout on your own. We suggest that you find some available layouts online. Print this out for convenience. You can also alter the response system. This refers to the sound that comes after metal detection. Usually, this is a buzzer. But since you are doing it for experimentation, you can add any other sound. To make it fun, people add unrelated music. Always keep the schematic at hand while making it. You still need to know the theory before you apply. This is why the layout is essential. 

Step 3: The Coil

The coil is the backbone of the detector. It is a quick processing unit. This is where all the action happens. As you can tell, making the coil is also the most difficult part. You need accurate measurements for the coil. If you are unsure about the dimensions, use the layout. This is why we suggest that you use an existing layout instead of making one on your own.

This requires a lot of education and physics knowledge. We do have a few rough measurements in case you are still lost. With a coil that is 90mm, you will need roughly about 250 to 270 coil-windings. If the coil diameter is 70 mm, you will need to increase the windings. You can push this to 290 windings. Since this whole experiment is a DIY, you can make your coil.

You will need strong cardboard and a geometric compass. The coil is made using copper wire. Do not use regular copper wire. If possible, use lacquered copper wire. Use the general dimensions given above. Now, you might have to do a little soldering.

If you do not have the equipment for this, you can quickly run to an ironsmith and get it done. We are not entirely self-sufficient, right? If you are soldering it on your own, clean the coil and cardboard. Use sandpaper for this. If you are still uncertain, you can buy a coil. It will save you time. But if you want to make a metal detector from scratch, follow the above points. 

Step 4: Test Run

A metal detector requires a lot of test runs. You cannot continue making the detector without conducting at least three test runs. Before completing a test run, you have to assemble all the materials. Spread out all the materials and connect the circuits. You will have to be very careful with the PCB. Sometimes, people attach a board under the circuit. This is called a breadboard.

A breadboard absorbs the detected metal. It provides a buffer for the circuit. The first test run is accessible. You simply have to switch on the device. A DIY metal detector is battery-run. So use fresh batteries. Then slowly run a small metal over the laid out materials. Depending on the processing unit and sound, you will get different results. If you have installed a ‘beep’ tone, it will be loud if the metal is close to the device. 

Step 5: Structuring

Once your raw test run is a success, you can now make a metal detector. Now you can style the sensor however you want. You can use cardboard to make the handles. Avoid using mountboard. Mountboard is very weak. It will cause the whole device to collapse.

The handle has to be very strong. This is what holds the main components of the detector. The handle consists of the switch, battery and circuit. To put the whole device together, you need a rough sketch. Initially, there is no need to use accurate measurements. Just for safety, make three to four cutouts of the handle. Having multiple layered handles will make it strong. Now you need to make openings for putting the other parts. Make appropriate incisions on the cardboard.

This is easy to estimate. Check the size of the materials and make the cuts one inch bigger than that. Glue three of the cutouts together with super glue or wood glue. This needs to dry. Leave it for about ten to twelve hours. The cardboard has to become as strong as wood. Once the glue has completely dried, you have to make space for the switch.

The switch needs ventilation because it is connected to the circuit. You have to punch a hole onto the wood. This is for the switch and the wires. This hole should be of moderate size. Too small a hole will choke the cables. The last step of the structure is adding the coil. Now the coil can be attached 3 inches away from the switch. Use hot glue for this. Once you have made the cut and holes, put it all together. The steps here are essential. You first need to put the switch, then the battery. Lastly, put the PCB and coil. Once everything is dry, you can test the detector. The whole detector will look like a circular vacuum cleaner. 

Step 6: Testing The Device

Now, once you have assembled everything, you can test it. Run a metal device over the detector. Remember that this is just for small devices. You will have to keep the metal very close to the detector. If you assembled everything correctly, the detector would work perfectly.

Method 2: Using A Calculator To Make A Metal Detector

By now, after looking at the previous steps, you know that making a metal detector is not easy. It requires a lot of accuracy and patience. If you are at the verge of discarding the idea of making your own metal detector, we have something in store for you. We were doing our research on DIY metal detectors.

This was when we came across this fun way of transforming a calculator into a detector. Any method you use will need some use of science. However, our website has brought you an easy way to do this. We always have your back. All you need is a calculator and a few household items. This method is low cost and highly effective. Moreover, it does not involve cutting, pasting and using the equipment. This can even be a good backyard science experiment for children.

Step 1: Assemble The Materials

We will give you a list of all the things you need. Some of the terms might be quite technical. We will try our best to simplify it. However, you need to know that making a metal detector is not child’s play. You will need a little physics and geometry to make it work. If this seems too difficult, you can try the other alternative.

While you gather the materials, be careful of the product quality. Sometimes, the detector does not work because of faulty materials. These are small particles. They are readily available in any store. Avoid purchasing things online. The size and quality might differ. The things you need for this detector is very simple. You will definitely have a calculator at home. However, besides this, you will need an AM radio. We don’t live in a generation of radios. Radios are history now. But for this project, you are going to need one. You can buy a small radio. The small ones are inexpensive. This will be within your budget too. 

Step 2: Adjustment         

Making a calculator based metal detector is fun. The radio acts as the siren. First, you have to switch the radio on. Keep the antenna in good coverage. Once you switch it on, find a high signal channel. This is the highest end of the bandwidth. You do not have to tune into a channel. Remember this. You just have to keep the tuning between two channels. You should be able to hear the static of the radio. Make sure you stay away from the channels. If your radio is old, it might take a while to catch the signal. Keep the volume high, so you will know when you have reached the desired channel. The static should be loud. 

Step 3: Positioning The Devices

The primary thing you need for this project is a calculator. Any kind of calculator will do the job. If you want the best results, use a calculator that is of the same size as the radio. This will help you in further steps. For now, you have to position the radio and the calculator. Keep them in close proximity. Both the devices have to be switched on. The best way to do it is to keep the calculator on top of the radio. Due to the antenna and sound waves, the frequencies will interact. In two or three minutes after the positioning, you will hear a loud noise. This will be a beep or a loud static. Once you hear the tone, try not moving the devices.

Step 4: Putting It Together

This will be a challenge if you do not have help. After you find the position, keep the device as it is. If you move it around too much, you will lose the position. If this happens, you will have to start over. This can be very time consuming and frustrating. Therefore to avoid this, seek help. After you have found your position, press both the devices tight. Now, ask someone to tape the radio and the calculator together. Once again, do not lose the placement. Tape it firmly. Either of the devices should be unable to move. 

Step 5: Testing It

A metal detector requires a lot of test runs. You cannot continue making the detector without conducting at least three test runs. Before conducting a test run, you have to assemble all the materials. Spread out all the materials and connect the circuits. The first test run is easy. You simply have to switch on the device. Switch on the radio. You can use any type of metal for the test run. Now comes the fun part. Each time the metal gets close to the calculator, it will beep. The calculator will make the same beep tone as in the previous step. The fun part is that as you take the metal device closer to the calculator, the beep rate will increase. This will sound like an ECG machine. Therefore, a calculator metal detector is smarter than the previously used method. 

Step 6: Understanding The Science Behind It

At the very beginning of this article, we told you about the importance of having knowledge. You need to know why a metal detector functions the way it does. Therefore, in this method, you do not need to use or attach any battery or circuit. All of this is inbuilt. You will simply be extracting the waves and power from the battery. Calculators have a circuit that produces the same frequency as a radio. Therefore, the radio waves and the calculator circuit act together. These waves are now quite strong. Once you bring a metal device close, the waves bounce off the metal. This causes a beep tone. Therefore, as you can see, this is a fast and easy way of making your own metal detector. 

Things You Will Need

Both methods have different requirements. The so-called simple method needs an elaborate list of things to make a metal detector. The second method needs only three household appliances.

Method 1: The Simple Method

Internal parts needed:

• Triple 5 coil.

• Ohm resistors

• 9-volt switches, batteries, cable and wires

• Copper wires

• Gaffer tape

• Superglue

• Buzzer

Tools needed:

• Cardboard and breadboard

• Soldering wire and iron

• knife, ruler, pencil, geometric compasses

• Schematic chart

Method 2: Using a calculator

You need only four things for this method. These include an AM radio, a calculator (scientific or normal), scotch tape. The fourth thing is metal for the test run. You can use a spoon or a knife. 

Final Thought

We hope this article gave you a fair idea about metal detectors. These are devices used for extreme security. However, it is important to keep in mind that DIY detectors have a shelf life. They will not go on forever. It depends on the battery, coil, and formation.

The good thing is that you can always rebuild it. The second method is easier and children-friendly too. This can be a great way to teach children simple rules of science.

You can do a fun experiment out of this too. There are no safety hazards with the second method. If you are trying to push your boundaries, then try the simple method. It requires a lot of patience and accuracy. We hope you enjoyed the process. Moreover, if you want to buy one, you can choose an amazing metal detector for yourself.