How to Modify a Servo Motor for Continuous Rotation ( One Motor Walker Robot )

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Introduction: How to Modify a Servo Motor for Continuous Rotation ( One Motor Walker Robot )

About: I am a French Canadian that loves robots and embedded electronics. I work on all kinds of cool projects, like a high-power electric push scooter controlled with an Arduino. Please visit my website for more ...

This instructable is part of the one motor walker.
https://www.instructables.com/id/How-to-build-the-one-motor-walker/

There are trillions of tutorial like this, I know :-)

They where taking at school during lunch break with a Sony Mavica camera ( floppy disk )!
5 febuary 2001, 12:18:50

Step 1: How to Modify a Servo Motor for Continuous Rotation ( One Motor Walker Robot )

The recommended tools for this project:
1 x safety glasses!!
1 x soldering iron
1 x desoldering pump
1 x wire strippers
1 x side cutter
1 x scissors, knife, x-acto, etc

You will need a set of screw driver to remove the four screws on the back of the servo.

Step 2: How to Modify a Servo Motor for Continuous Rotation ( One Motor Walker Robot )

I put a peace of tape so the gear box does not come appart when I remove the back cover.

Step 3: How to Modify a Servo Motor for Continuous Rotation ( One Motor Walker Robot )

Remove the back cover by removing four screws.

Step 4: How to Modify a Servo Motor for Continuous Rotation ( One Motor Walker Robot )

If you use a solder pump, it will be easy to desolder.

Step 5: How to Modify a Servo Motor for Continuous Rotation ( One Motor Walker Robot )

Be sure you have remove every solder before starting lifting.

When you are sure, take a flat screw driver to lift it.

Step 6: How to Modify a Servo Motor for Continuous Rotation ( One Motor Walker Robot )

Solder long wire to the motor.

Use the original servo wire. Remove the white wire.

Step 7: How to Modify a Servo Motor for Continuous Rotation ( One Motor Walker Robot )

This is the inside of the gear box.

Step 8: How to Modify a Servo Motor for Continuous Rotation ( One Motor Walker Robot )

After some thinking, I realise that you don't need to cut the tap for the one motor walker.
If you want to build the one motor walker, I suggest you try the to build the robot without cutting the tap.If you want to make a rolling robot by using servo motors for the locomotion then cut the tap.

To cut the tap please read carefully.

Warning!

I have already broken the entire gear by using a side cutter. I was sort of piss off!
I recommend you be carefull and use a hacksaw.

Take your time!

Put every thing back together and you have finish!
You can put some new grease it the gearbox if you want.

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    79 Comments

    If you would have replaced the existing potentiometer with a micro 5k potentiometer and centered it (google it ;) ) in addition to removing the limiting pin, you would have a "positionable" 360 degree servo motor that can be used with any device that will drive a standard servo and also used where a "stepper motor" can not at times due to space constraints... Like a small miniature robot crawler where even a NEMA 8 stepper is a bit large? Had that headache more then once! :)

    Keep up the good work. Looking forward to seeing more. :)

    if you follow this instructable and remove all electronics, you simply apply 5V directly to the motor and it will spin continuously.

    If you modify it for continuous motion can you still get the servo to return to its original position? I can get it to move with a flex sensor but once i stop it will not return to its original position before it was modified. Help

    so there is no pulse pin instead you program it like a dc motor but no motor driver right

    1 reply

    yes, no pulse pin.

    It's a DC motor. You use it like any motor.
    Depending of your application you will need a motordriver to control it.
    It's call an H-bridge for example.

    Can a servo make continuous rotation very acuurately (say 533 degrees 56 ' 00")

    8 replies

    no, get yourself a stepper motor.

    cna i also know the acuurate position of the motor after movt??

    a servo motor returns back to it's orginal position, ya? this is the EXACT same thing, but without the tab, so you can keep turning whatever it is you are turning before returning back to it's normal position.

    remember that the potentiometer inside the servo motor is not design to turn more then 1 turn. He wanted to turn 533deg. A winch servo motor could work since they turn more then 360deg.

    Ah, I see. I haven't really delved into the nitty gritty of how some of my rc equipment works, so I only know what they can do because I've had to troubleshoot them a lot.

    can it make continous rotations say 20 rotations and what's the cost??

    thnx for the reply

    have you google "stepper motor" or "stepper motor tutorials" before asking your questions?

    Stepper motors are exactly what you are asking for. You know the precise position of your motor after movement and you can say turn 20 turns.
    It will cost you 17.95$. No, the price of a motor can varie a lot. You need special electric components to drive stepper motors. Check pololu, adafruit and sparkfun to buy the motors and electric components.

    what is the rpm ofthe servo when used as motor?

    i want to know the program code used in the rotation of arm of humanoid robot urgently

    my email is- hansswati63@gmail.com

    1 reply

    here

    #include

    Servo myservo; // create servo object to control a servo
    // a maximum of eight servo objects can be created

    int pos = 0; // variable to store the servo position

    void setup()
    {
    myservo.attach(9); // attaches the servo on pin 9 to the servo object
    }


    void loop()
    {
    for(pos = 0; pos < 180; pos += 1) // goes from 0 degrees to 180 degrees
    { // in steps of 1 degree
    myservo.write(pos); // tell servo to go to position in variable 'pos'
    delay(15); // waits 15ms for the servo to reach the position
    }
    for(pos = 180; pos>=1; pos-=1) // goes from 180 degrees to 0 degrees
    {
    myservo.write(pos); // tell servo to go to position in variable 'pos'
    delay(15); // waits 15ms for the servo to reach the position
    }
    }

    i want to know the program code used in the rotation of arm of humanoid robot urgently

    my email is- hansswati63@gmail.com

    bro robomaniac i m not able to understand that how is the circit and the motor to be connected to each other in the servo motor after modification plzz help me out..

    i have got a question, if i cut this part off and everything is going to be fine will i be able to write something like 360 in the program?