I am using DC motors to build a robotic arm. I want to make the base shoulder (which rotates and lifts) more stable and stronger. How should I design this using DC motors?

Also I would like to put the motor for the elbow in the base for efficiency. Which design best suits this?

UPDATE I am building a robotic arm for a payload of approx. 1-2 kg and using DC high torque motors. In this model, I am using only a shoulder with a gripper. The gripper is self made by me weighing approximately 400 grams. I want to have a proper design and material choice so that the shoulder part remains less heavy and more stable.

In addition to this I want to operate the movement of the gripper, i.e. the up and down motion, by using the motor in the base part. What should be my design and better alternative?

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    $\begingroup$ Could you give some more explanation of your current design concept, so that more effective answers can show up? $\endgroup$ – Gürkan Çetin May 23 '15 at 17:46
  • $\begingroup$ Thanks for the suggestion, I have updated my question with some more details. $\endgroup$ – Ravi Vashisth May 25 '15 at 10:17
  • $\begingroup$ how many total degrees of freedom will it have? 2 in the base and 1 in the elbow + 1 in the gripper? what is the length of the arm? what is the intended use? what kind of sensing will it have / need? how fast / accurate does it have to be? you need to provide much more information if you want informed answers. $\endgroup$ – Ben May 25 '15 at 19:24
  • $\begingroup$ it will have a degree of freedom of 2 in base, 1 in elbow and 1 in gripper, The length of arm includes 30-35 cm from shoulder to elbow end, 10 cm from there to gripper or less. The use of this arm is for lifting or simply can say pick and drop like function. I am using ATmega32 right now for programming and speed is not an issue right now. $\endgroup$ – Ravi Vashisth May 26 '15 at 16:59

We built a robot arm similar to the model in the following link.


We used 3D-printer to print all the links so the link mass is small but strong enough. BTW we only used cheap servos but the arm moved not bad so I think the high torque motors are okay. I suggest you start with a 3 DOF arm and if you want any design reference you can search on grabcad.com. There are plenty of great design models. Have fun!


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