Robotic arm is the most common robot found in industries. Robotic arm is a programmable mechanical arm made up with several joints connected together. Links of the robotic arm forms a kinematic chain with an end-effector or robotic hand. The computer controls the robot by rotating individual motors connected to each joint.
In industry several kind of robotic hand(end -effector) are used like welding, gripping etc.
Here in this tutorial we are going to build a 6 DOF robotic arm from scratch.
Arm is made using simple tools no CNC or laser cutting required. Those who wants to make a cheap robotic arm with simple workshop tools can follow this tutorial.
Material or Part List
- MG996 servo motor x 5
- SG90 servo motor x 1
- Standard servo bracket x 5
- C bracket small x 1
- Gripper(end-effector) x 1
- Servo Controller x 1
- USB-Serial converter x 1
- Arduino Uno x 1
- Base Plate x 1
- Standard Servo Bracket Design
To make a servo bracket yourself. Download design files.(Links are given in bottom)
Take a printout with 100% scale. Cut exact dimension of design of servo bracket on paper.
Cut a dimension of 60 mm x 78 mm out of 2mm aluminium sheet. Now glue this paper on the aluminium piece.
In the design I have placed small circles of .5mm radius inside each circle. Get a center punch and hammer, put the punch on small circle and strike it using hammer so that there is a small mark on aluminium sheet exactly at the center of larger circle.
After tapping each circle, you can drill it easily and holes will be quite accurate. You will need 3mm, 4mm, 8mm drill bits.
After drilling, it’s time to cut the sheet at two parallel lines marked as 25mm
Now hold the bracket in vice tightly and bend at marked lines. See images below.
Now we can wash the bracket to remove the paper. Below is finished servo bracket.
Go and make another four standard servo brackets.
2. C Type Servo Bracket
Now make 1 C-type servo brackets similarly as mentioned above.
2. Straight Joint
Similarly make these two plates which will be used to make 2 joints.
One plate will be connected with servo horns and second is to provide support at back side of motor. Second plate will be joined using small rivets.
Programming and testing the arm
For controlling our robotic arm we are going to use MRG servo controller board.