For my first "newbie" experience in the world of robot arms I played with RC Servo Motors. They are relatively strong and compact plus they have their own gear reduction.

This project was a 3-Axis arm - a rotating base and two joints. Having built hundreds of speakers using MDF, naturally the base and arm segments were made with MDF :)
V Click thumbnails for full size V


I used a Hitec HS-7980TH Mega Torque motor for the base rotation and shoulder joint. And a Hitec HS-5805MG motor for the elbow joint. These motors are amoung the strongest RC servos.

And I used a YEI Servo Center board as the motor controller and driver. This board could drive up to 16 motors, as long as you didn't exceed a total draw of 1-amp. And you can daisy-chain up to 16 boards for a total of 256 motors!

The motor board could take simple serial commands from a PC, so I wrote my first robot arm motion app in C#/.NET WinForms.

Some pics:



Some videos:



This worked okay until the shoulder joint failed. The tiny plastic teeth of the servo horn shredded :( I should have expected this but ... first lesson learned for a newbie.

Thousands of very cool robotic projects can be made using RC servos, but as for a strong arm capable of lifting some weight these little guys just wouldn't do.

So on to my next project - Stepper Motors.