A thermocouple is a small,namable piece of metal that changes shape when heat is applied to it. When it is heated to a specific temperature, the metal becomes more round and thinner in order to tolerate more heat.
This allows you to connect a thermocouple device to a device such as an oven or rangehood. Once connected, you can regulate the temperature via a cooktop or by using a hot water system.
There are two main ways of making a thermocouple. The first is to use an electronic device such as an oven or rangehood and connect it to a liquid-based sensor. The second is to use a solid-based sensor and make your wire insulation thicker.
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Print the shape
Once you have your thermocouple, it is time to print the proper shape. Most thermocouples are circular, but if you want a linear one you must print the required length.
Circular thermocouples have a diameter that is equal to their length. They can be difficult to place in hot water due to the circle shape, but they should still be inserted into the water as soon as it is placed onto the printer.
Linear thermocouples do not have a diameter that is equal to their length. They must be placed in cold water before being inserted into the hot water, and then heated before being connected to an object.
Find a metal rod
When you’re ready to make your first Thermocouple, the first step is to find a metal rod about 6-8 inches long. You can buy them in hardware stores or specialty electronics stores, but they usually aren’t very expensive.
Usually, these rods are sold as thermometers or probes, but you can make a Thermocouple without a thermometer if you have one!
Why use a thermometer? Because it gives you an idea of how hot the environment is. A thickly insulated pot will not heat as well as an open pot with an alert sensor on it.
Find a metal disk
There are many uses for a metal disk. You can make jewelry with them, paint them with thermal paper, or create tech tools. Any of these can be very fun!
In all cases, the disk must be placed in a container with heat. The container should have adequate space to allow for temperature change.
If you do not have a metal disk, you can still make a thermocouple! In this case, you just need to wrap your finger and/or hand in warm cloth to create the same effect.
You can also make both types of thermocouple using the same hand- and finger-based method, just use different surfaces to wrap on.
Sand the disk flat
Once you have your thermocouple, the next step is to make it sanded. You can do this by using a power tool or by hand, both!
With the use of a power tool or hand, first mark the perimeter of the disk with a pencil. Then, using a knife or utility knife, cut into the disk along the marked area.
Finally, gently pull out the cut piece and sand away! This can be done several times until you have a flat and smooth thermocouple.
Useful links: See this link for more information on how to make an alcohol-based thermal probe using your new thermocouple.
Shape the end of the rod into a rounded tip
When working with thermocouples, it is important to shape the end of the rod into a rounded tip. This prevents your thermocouple from getting stuck in a straight, sharp-tiped thermocouple.
A flat-tiped thermometre can easily be forced up into a hole and then pulled out again, due to the heat that has been applied to it. This can cause it to break or remove some of its stability.
When making your own, you will need to apply some epoxy in order for the round tip to stick, and then you can finish digging it in!
How do you make one? You can start by purchasing a long metre lead, cut them down to your desired length, and then applying some epoxy on top of that.
Sharpen the other end of the rod
Once your Thermocouple has a good length of copper wiring in the other end, it is time to make some improvements. You can do this by heating the metal with a hot iron, or by bending the copper wire until it is round.
Wrap copper wire several times around the disk, then twist it together and solder it
Once you have your Thermocouple, the next step is to wrap it in more copper wire. You can use whatever thickness of wire you want, but make sure there is enough space between the two wires.
Then, twist the two wires together and solder them to create a circuit. This process takes a little bit of skill and practice, but can be done!
Now that your Thermocouple has a location where it can heat an object, you are ready to use it! Use it as described in previous articles, or create some new uses for it.
Wrap copper wire several times around the rod, then twist it together and solder it
Once you have your thermocouple, you need to wrap it in some kind of insulator. The copper will conduct heat, but the insulation protects the rest of your device from that.
You can use electrical tape, or you can use non-conductive material like paper towels or towels. Non-conductive material is usually what you want if you are going to wear your thermocouple on a clothing item.
Make sure to put some extra insulation on the end where the wire goes into the device. This will prevent it from getting cold and failing.
Now that we have our thermocouple, we are going to connect it to our device! First, we wrap the end with some extra insulation, then twist together the two wires and solder them. Using an all-purpose solder is good for this step.