Robotic Servo Arm

We're going to make a robust robotic arm which can lift weights and move it. Lets get started with this cool stuff.

Step 1: Making a Robot

This project is about doing a robotic servo arm. I've used 2 stepper motors and 2 servo motors here. We can also use servo instead of steppers but steppers are more durable and precise.They can also handle more weight which will be useful here as I've used steel instead of plastic for the parts.The main control is done by using an arduino uno. The power supply was given from laptop directly. But we can also give 5V supply directly using a battery.

Step 2: All About Steppers

For stepper we need motor drivers uln2003 or uln2004 and l293d based on the mode in which we use them. For unipolar mode,we need darlington array to amplify the current and for bipolar mode, we need a h-bridge motor driver as we need to give bidirectional power supply. I've used the steppers in both bipolar and unipolar modes in this project. Bipolar mode gives more torque while unipolar is more accurate when it comes to step size. Based on the data sheet of stepper motor, we can calculate the steps taken for one revolution.The gear ratio and step size will be available there.

Step 3: Connecting the Parts

The connection diagram is given below. Care must be take to ground all the gnd connections with the gnd of arduino. For servo we can directly give 5V taken from the arduino board. But stepper draws more current.So we need to provide a separate source not more than 5V for the steppers if the rating is 5V. We can also regulate the voltage using voltage regulator IC 7805. Refer the pictures to connect the components.

Step 4: Arduino Code

Copy paste the code in the arduino ide. If you don't have the libraries included in the code,please download them before running the code.Enter the no. of steps you want your motor to go. The first stepper is the one in the base and the stepper2 is the one which controls the height of the servo motors. Next, you need to enter the angle in which you want the servos to go. Calibrate and position them properly so that they go in mirror motion.

Step 5: Final Steps

Connect everything securely using jumper cables and mount them securely .Try your best to balance the setup from tilting. Screwing down the stepper to a wooden frame might do the job.After uploading the code, you can lift some object and control it to place it at some other location. You can even add this to a robot on wheels and make it big!