Introduction: Servo Modification for Continuous Turning (Simple)

Hi Guys. So today I'm going to show you guys how to modify your servo for continuous turning/rotate in a very simple way. I believe that you have Google-Ed the way to modify your servo for continuous turning for your own purpose. I modified my servo to make a mini Spy Tank, what about you? Comment below and let me know ;)

For people who are on a rush. Skip to the last step.

BTW sorry for poor English

Step 1: Clean Up Your Working Desk !

Clean up your working desk before you start all of your project. A messy desk doesn't help !

Step 2: Prepare Your Tools

In this project you will need this things:

1x Servo that you want to modify

1x RC transmitter & receiver (or anything that you use to control your servo e.g Arduino)

1x Battery to power up the electronic parts

1x Hammer

1x Tools required to disassemble the Servo(screw driver)

1x Hot Glue Gun and Hot glue for sure

Step 3: Disassemble Your Servo

Not necessary to remove all the parts of it. Follow the steps and you'll know what you need.

Step 4: Find the Gear With a Pin on It

In Servo motor, there is always a gear with a little Pin to prevent the Servo to overturn and damage the Potentiometer inside the Servo(normally it's the main Output Gear of the servo) Since the Pot can't turn 360degree continuously. Find out the gear and start working on the little pin. I used hammer and simply knock the pin into the gear, there's still some space below for me to "store" the pin inside the gear. Beside using hammer you can use other way you like to remove or make the pin become completely flat with the gear surface. With this, the Pin will not stop the Servo from turning continuously anymore.

Step 5: Shorten the Potentiometer

Find the potentiometer and shorten the 'handle' of the Pot.

For those who don't know how the Servo motor works, basically there's a Potentiometer inside the Servo and controlled by a Circuit board. The Pot read the position/degree of the main output gear because they both are attached together, this is the reason why we want to shorten the potentiometer to prevent the pot turns with the output gear when the servo start turning. When you transmitter a signal to the board, the board immediately read the position of the pot, if the pot isn't in the right position, it will send the signal to the motor to start spinning until the position you sent is reached, otherwise it will keep on spinning. Yes, this is how we are going to modify it.

Step 6: Working on the Potentiometer

Power up the electronic part of the servo motor(always beware of short circuit, so don't work on a electric conductive place). Sent any signal that you want the motor to be stop at. In my case, I want the motor to stop at middle of my throttle of my transmitter. So, I pushed my throttle about 50% where i want it stop. The motor should start spinning crazily. In this moment, start to turn your potentiometer slowly to left or right until you find a place where the motor stop spinning. Use your hotglue or other things else you want to keep the potentiometer in place.

And Done ! Just reassemble your servo and you're good to go.

Tips:

Put some grease on the gear before reassemble.

Electronic parts don't have to assemble back into its original place (just simply put into the free space inside the servo. For reason why, in my case, i put too much hot glue on the pot and it stuck when I want to reassemble it back to place. This safe up sometimes for assemble or disassemble the next time also)

Step 7: Extras

Some of you may have seen some person online used resistor to replace the pot.If you guys are wondering, this if how it works.Potentiometer have three pin the 5v, Signal and Ground pin. When the pot is at '0' , the resistance from 5v to the signal pin is '0'. When the pot is at maximum value, resistance from 5v to Signal pin is also at maximum(normally for a servo pot is about 5k ohm, you can find out yours using a multimeter and hook up both 5v and Ground pin). So, they used two 2.5k ohm resistor, one connect from 5v to signal and another one from signal to ground. This should keep the resistance at the middle. This is same as turning the potentiometer to the middle value.If you wanted to let your Servo stop at '0' , you should use a 5k ohm resistor and connect it from 5v to signal pin and bypass signal and Ground Pin(use some small value of resistor instead of bypass is better, but bypass will do)

But i believe that some of you may not have the exact value of resistor lying around. So i created this Tutorial for all of you.

Step 8: Overview

Step 1: Disassemble Servo

Step2: Remove Pin from the gear that stop the Servo for continuous spinning

Step3: Shorten the 'handle' of pot to prevent it from turning together with the gear

Step4: PowerUp servo and things you use to control the Servo and set to value where you want the Servo to stop

Step5: Turn you Pot into position where the motor stop spinning and secure it in place(Hot Glue or anything else)

Step6: Reassemble and Done !

Comment below and let me know what i can improve !

Comments

author
Anirudh Ralhan (author)2016-11-22

That is a nice and well explained Instructable. Thanks for sharing :)

author
Sooncheng (author)Anirudh Ralhan2016-11-22

Welcome and thanks too