Hi!
I am making a Spray Painting Robotic Arm as my final year project. I want to select an appropriate motor for each joint of the robotic arm. I am using Aluminum for the structure of the robotic arm having density 2.7 gram/cubic centimeter. Also I am using Air brush for painting purpose which weighs around 500 g. So which motor will be suitable? stepper or servo?
You’ll need to estimate the weight of the motor as it’s very important to the calculations. Over-estimate if necessary. If you are considering a stepper motor, the only way to get enough torque would be to use a geared stepper motor. Note that these are quite a bit more complex to control than servos and you would need some way of zeroing them since their angular displacement is relative, whereas for a servo motor it’s absolute.
Not sure what you mean. Can you include a small image?
Finding the center of mass for a 3D object is not straightforward and is best done by experimentation. That depends on the orientation in which you will pick it up. A spray gun is certainly an odd shape, but you can assume the part is symmetric about at least one axis. For the other two axes, the most important is the distance between the center of mass along the X (horizontal axis) and the axis of rotation. Try balancing the spray gun at the center along its length and move the points of contact until its roughly balanced.
The part looks symmetric about three axes, so the center of mass would be located in the center of the part (overall length / 2, 25, 1.5).
You can come to the right place. Take a look at this guide to get you started choosing the right servo. Once you have read through the Robot Arm Torque Tutorial, use the Robot Arm Torque Calculator.
yesterday, i open the package of my Arduino robot arm and turn all arms up, carelessly, i broke one arm with little scrach, how should i fix this?
Thank you so much. So nice of you. One more thing I would like to ask is about the center of mass of the object. In tutorial, It is taken as the mid point of the length of the object. So, How do I found the location of the center of mass of my object?
Since my robotic arm has 5 degrees of freedom, so how do I calculate the center of mass of each individual arm linked together to make a complete arm? I have attached a drawing of one of the individual arm. I want to calculate the center of mass of this arm.
Should I use servo or stepper?
In Robot Arm Torque Calculator, I don’t know the weight of the motor I am going to use. So What would be the mass of the actuator/motor?
Thank you so much 