How to Make a Fully Rotational Servo

Tutorial by YNZE- via Instructables.
In this Instructables I will show you how to make a fully rotational servo from a standard 9g servo. This is my first Instructables so I hope you like it.

Step 1: The Parts And Tools You Will Need

For this project you will only nead two parts:

• A 9g servo

• A small 5K ohm potentiometer 

You will also need the folowing tools:

• Soldering iron

• Solder

• Knife

• Screwdriver

• Drill

• Tape

• 'Arduino and pc' or servotester

Step 2: Take The Servo Apart

First screw all the screws out of the servo and cut the stickers so you can take off the bottem and top part of the servo.

Now take out the motor, the sercuit board and the gears and cut the wires that go to the potentiometer as close to the potentiometer as possible.
Don't forget where the gears go :)

Step 3: Modify Some Parts

Take the bottom piece of the servo and drill a hole of about 5mm in the middel. After that we nead to cut the little piece of the biggest gear, check the pictures for more detail.

Step 4: The Old Potentiometer

Now take the potentiometer from the servo and cut the leads where the wires normaly go as short as possible.

Next we have to take the wiper out of the potentiometer so the shaft can turn freely (this can be a bit difficult), if you did it right it will look like the picture.

I broke mine a bit but that is no big deal.

Step 5: The Sercuitboard

 

Put a Tiny piece of tape on the chip on the sercuitboard of the servo to prevent shortsercuits (make sure to cover the leads of the chip aswel).

Cut the middel lead of the 5K potentiometer a bit shorter and solder it on to the sercuitboard where the old potentiometer was.

Step 6: Put Everything Back Together

First put back the modified potentiometer and put a piece of tape on it to prevent short seruits.

Now put back all the gears and put the top part of the cover back in place.

Now press the motor back in it's place and put the sercuitboard with the potentiometer facing out (upside down) in the case.

Now close the servo with the endcap with the hole in it and put the screws back in place.

Step 7: Finish The Servo

Now is your fullyrotational servo done.

You will only have to copy the code below or use a servo tester and calibrate the servo.
Upload the code to the arduino.

Plug the servo into the arduino.

Run the code and turn the potentiometer left and right until the servo stops turning.
Make sure it does not turn or make noise anymore.

Now you are done and you can use the servo.

If the servo starts moving again at a given moment, you can always turn the potentiometer to calibrate it.

The code:
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/*This very simple code will set the servo to 90degrees.
*connect the red wire to 5volt, the brown wire to ground and the yellow wire to pin 9 of the arduino.
*Made by: Ynze Selders
*/
#include 
Servo myservo;
void setup() {
myservo.attach(9); 
}
void loop() {
myservo.write(90); 
}
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If you want to do it with a servotester you only have to plug the servo in to the servotester and set it to 90degrees. Now you can turn the potentiometer until it stops turning.

Source: Instructables