This week I have spent some time in the garage and a lot more time on the computer. The garage time has been spent rebuilding a biped robot built by Auzieman. He has a great site that is devoted to homemade robotics and everything related to building and programming them. This particular robot is a biped that uses six Futaba S3003 servos controlled by an Arduino board. The power supply is connected via an umbilical to save weight. The task that I have undertaken is refining the mechanics and making everything a little less loose! Think of it as a robotic 'shave and haircut'.
|Arduino Controlled Biped Robot|
The concept here is to build a robot that uses mostly similar or exactly the same brackets and servos to save cost. Developing a universal bracket that mounts Radio Controlled style servos is a difficult task due to the shape and size of RC servos. These types of servos are meant to be used in model cars and boats and not specifically as structural elements so they have very limited mounting points on one side only. A universal bracket then has to 'wrap around' the servo and provide holes/surfaces to mount whatever you dream up.Because of this universal requirement the brackets have a lot of complicated and relatively close tolerance bends. In many applications there is some unused surfaces and flanges that are just adding weight. With this in mind a universal bracket has to be made of thin and light material like aluminum sheet and use the servo as much as possible to provide the strength and rigidity. This means that hand making brackets of this type is difficult and requires some specialized tools.
My task this week is to take this robot apart and try and clean up the brackets and pivots. Anything loose in a robot makes accurate positioning of the appendages impossible.
|Universal Servo Bracket Concept|
So far this has been a pretty straight forward task. Due to the limited space getting all the screws in with nuts on them is a pain but possible with patience and a good pair of needle nose pliers!
Check out Auziemans blog for details on the robot construction and how to make an Arduino board talk to Futaba servos. there is a lot of good information there about the electronics and programming challenges of DIY robotics!