Coil Winder Using Arduino

Why this project was built?
I work at Prabal Learning Innovations, an educational startup. One of our educational kits contains a 3D printed part that is wound with a copper coil to demonstrate electromagnetic induction. Winding the 3d printed part usually requires two people, one to hold the motor and the other to hold the 3D printed part. So, I built this machine, to do the job.

P.S. Check out Prabal. We make a lot of experiential learning kits and experiments.

What can this project do?

Even though this machine was built specifically for my company's needs, the code, as well as the design, can be tweaked as per different needs.

Step 1: Things Required

Step 2: Project General Outline

The whole setup is attached to a high-density foam piece using screws. A wooden piece or any other more rigid material would have been a better choice for this since the screws seem to lose their grip eventually because of the not-so-rigid nature of the foam.

Step 3: Connecting the Hall Sensor

I have used a hall sensor module to count the number of windings. The hall sensor is a device that is designed to detect the hall effect. There are two different types of hall sensors - analogue and digital. I have used the latter.

To know more about hall effect and how the hall sensor works, refer to this video -

Each time the magnet attached to the motor goes past the hall sensor, it goes HIGH. An interrupt function is used to count the number of times the hall sensor goes HIGH (thus counting the number of windings). The image shows how the hall sensor is connected to that Arduino.

Step 4: Connecting the LCD

The LCD display is coupled with the I2C module and connected to the Arduino. The image shows how the LCD display is connected to the Arduino.

Refer to these videos to know more about LCDs and how to connect them to the Arduino.

Step 5: Connecting the Servo Motor

The servo motor distributes the copper coil evenly across the 3D printed part. The image shows how the servo motor is connected to the Arduino.

Refer to these videos to know more about servo motors and how to work with them.

Step 6: Connecting the Push Button

The pushbutton is used to confirm the input given through the potentiometer. The image shows how the pushbutton is connected to the Arduino through a pull-up resistor.

Refer to this video to know more about pushbuttons and pull-up/pull-down resistors.

Step 7: Connecting the Buzzer

The buzzer gives a beep sound as soon as the winding is done. There are two different types of buzzers, active and passive buzzers. I have used a passive buzzer. The image shows how the buzzer is connected to the Arduino.

Refer to these videos to understand more about buzzers and how to program them.

https://www.youtube.com/watch?v=dHYKRrlPNzM&list=PLGs0VKk2DiYw-L-RibttcvK-WBZm8WLEP&index=24

Step 8: Connecting the Potentiometer

The potentiometer knob is used to give the input regarding the amount of coil to be wound around the 3D printed part. I have used a 10KOhm potentiometer. You can use a different potentiometer. Use the schematics to connect the potentiometer to the Arduino.

Refer to this video to learn more about potentiometers:

Step 9: Connecting the Motor, Battery and Self-locking Switch

Use the schematics to connect the motor to the battery through the switch. Make sure to get the exact same switch. If you don't find it, you can always get a different switch and use the continuity testing feature of the multimeter to figure out how to connect it, to perform the same action.

Step 10: Connecting the Arduino

Use the schematics to connect the Arduino to the battery. I have used a battery pack made of three Lipo cells. The total voltage of the battery pack is 11.1V (3.7V x 3). The Vin pin allows an input between 7-12V. You can use a 9V battery, commonly available at stores.

Step 11: Code

Step 12: Calculations

NOTE: You will not need this calculation if you want to wind based on the number of windings, instead of the weight of the copper coil to be wound.

The inputs given through the potentiometer knob are just numbers between 0 -1024 (the analogue values that the Arduino reads). These values are then mapped between 0-30 (using the map function in the code). These values are nothing but the amount of copper coil (in weight) that the user wants the coil winder to wind around the 3D printed part.

The Arduino however is not equipped or assisted by sensors that can sense the weight. However, the program contains a hardware interrupt function triggered by a hall sensor, that helps the Arduino count the number of windings. Thus to relate the user's input and what the Arduino is capable of doing, a calculation outside the program has been done. It is a simple calculation that determines the number of windings required to wind a particular amount (in grams) of copper coil. The calculation equates the potentiometer input to the number of windings required to satisfy the input.

This is how it was done.

Step 1: I weighed the empty 3D printed part. Its weight was, say, 11 grams.

Step 2: Then I manually wound copper coil around it until the weight increased by 1 gram (from 11 grams to 12 grams).

Step 3: I counted the number of times I had wound. It was, say, 14 times.

Step 4: Now,

14 windings = 1 gram

Step 5: That's it. Just multiply the input from the potentiometer knob (after mapping it) by 14 to get the value of totalWindings. So, for example, if 5 grams of the copper coil has to be wound, then the value of totalWindings would be 5*14 = 70.

NOTE: Even though a significant part of the calculation involves the things that are specific for my project, the method, however, can be used for different projects.

Step 13: 3D Parts

Use the image map as reference to identify parts.

NOTES:
1. The 3D printer I used sometimes prints incorrectly. So, I had to round off a lot of the dimensions. So some of the slots/holes ended up becoming slightly bigger. Please edit the files as per your requirement. The designs are simple.

2. The lids of the "Arduino shell" and "box cover" were screwed on top. The "extension" parts were just glued using a glue gun. Frankly speaking, the "extension" parts were made because of the initial confusions in the design. However, having the "extension" parts gave me the freedom to debug the circuit while testing, without unscrewing the lids. I could just remove the extension parts along with the lid (since its just glue stick, it came off easily). You can omit the extensions by re-designing the "Arduino Shell" and "box cover" parts taller if needed.

3. If you don't find the exact screws, you can use different screws and re-design the slots/holes accordingly.

Step 14: Working Video

This is the working video

Step 15: Working

This is the downloadable file of the working video.

Comments

[xuguizhen83]

?

[xuguizhen83]

Arduino:1.8.19 (Windows 10), 开发板："Arduino Uno"
Coil_Winder:1:10: fatal error: LiquidCrystal_I2C.h: No such file or directory
#include <LiquidCrystal_I2C.h>
^~~~~~~~~~~~~~~~~~~~~
compilation terminated.
exit status 1
LiquidCrystal_I2C.h: No such file or directory
在文件 -> 首选项开启
“编译过程中显示详细输出”选项
这份报告会包含更多信息。

[shibunagendran220]

Hey everyone. Thanks for your love and support. Means a ton. I have updated the code file after some of my friends said that they couldn't open it. The code file has a lot of instructions (code description). I have tried my best to explain the code. Please comment if more clarity is required. I would love to work on that.
I have also added a few instructions to "Parts" section.
Thanks again.

[MotherGoose74]

Hello I can’t seem to convert the SLDPRT to STL. Is this something that is available or some guidance website to convert.
Thank you
Jay

[bettergenius]

Hi, In step 12 you mentioned about doing some calculations. Where in the code do you put that, I looked for your example in the code 5*14=70 but its not in there at all.

[SinL4]

Hi, what happens to this below ?

C:\Users\Downloads\Coil_Winder\Coil_Winder.ino: In function 'void setup()':
C:\Users\Downloads\Coil_Winder\Coil_Winder.ino:59:68: warning: invalid conversion from 'volatile int (*)()' to 'void (*)()' [-fpermissive]
attachInterrupt(digitalPinToInterrupt(hallPin),windCounter, FALLING);
^
In file included from sketch\Coil_Winder.ino.cpp:1:0:
C:\Users\sinch\OneDrive\Desktop\arduino-1.8.16\hardware\arduino\avr\cores\arduino/Arduino.h:151:6: note: initializing argument 2 of 'void attachInterrupt(uint8_t, void (*)(), int)'
void attachInterrupt(uint8_t interruptNum, void (*userFunc)(void), int mode);
^~~~~~~~~~~~~~~

[Rontapp]

I have the same motorspin error as previous comments, how did u solve this?

[shibunagendran220]

Heyyy. I sorry. My project is at my office and because of covid travel bans, I am stuck at a different place. I am unable get my hands on the project to figure out the issue.

The error seems as though the variable is declared as a local variable and not as a global one. Please try declaring the variable as a global variable.

[vtom013]

Hi I got weird error : Arduino: 1.8.13 (Windows 7), Board: "Arduino Uno"
C:\Users\7M\Downloads\Coil_Winder\Coil_Winder.ino: In function 'void setup()':
Coil_Winder:61:3: error: 'motorSpinFunction' was not declared in this scope
motorSpinFunction();
^~~~~~~~~~~~~~~~~. Can You help me with that . Thank You.

[shibunagendran220]

Hey :D
Sorry for the late response and sorry about the error. I am trying to figure out why. I will get back to you quickly. Thanks :D

[Rontapp]

Did u get an answer to this error?

[shibunagendran220]

Heyyy. I am terribly sorry for the late reply. My project is at my office and because of covid travel bans, I am stuck at a different place. I couldn't get my hands on the project to figure out the issue.

The error seems as though the variable is declared as a local variable and not as a global one. Please try declaring the variable as a global variable.

[vtom013]

Thank You so much.

[Luan Estevam]

boa noite ,estou com um problema no codigo ,e nao consigo compilar ele na parte ,motorSpinFunction pode me ajudar estou precisando muito ,gostei muito do seu projeto!!!

[thediylife]

This is really cool, I love how you've managed to use relatively cheap components to build this!
One thing you might want to consider in your code is to try using a variable speed of movement for the servo, so speeding it up at the ends of travel. Because of the time taken to slow down and reverse direction, you land up getting more winds at the two edges. Speeding up the servo movement near the ends of travel should help with this.

[shibunagendran220]

Hey. :D
Thank you. Means a lot <3
Ya, you are right. I will surely implement that when I build an advanced model of this.
Thanks for the suggestion :)

[Captain_Nemo]

Why did you use a physical switch instead of an H-bridge to control the winding motor?

[shibunagendran220]

A relay is also a good option to give Arduino the control over the motor.

[shibunagendran220]

Hey. Great question :)
Yeah, using an H-bridge motor controller is a better choice since it gives the control of the motor directly to the Arduino. The reason I did not use it is because the number of connections to the Arduino was already making it difficult for me debug. It was getting congested inside.
Probably, an upgraded version of this project will include the H-Bride integrated into the setup. It's certainly more reliable (but not as dramatic and satisfying as the servo arm pushing the self-locking switch). :p

Thanks :D

[acheide]

A detailed and informative Instructable. Thank you.