For a long time I wanted to build a quadruped robot. And... you guys may have seen in some of my videos that I have many dogs at my home (precisely four). What better inspiration I would have to build a robot dog?

Below you see my little buddy Sebastian, which accompanying me in the long nights in the lab.

Mechanics

The design process of the parts begins with a brainstorming, then I adjust the drawings to get something satisfactory.

Specifically for this project was also required a study on canine anatomy. Actually a very superficial study, just to maintain a similar morphology to a real dog.

All the brackets and mechanical parts are homemade with high impact polystyrene sheets and a bit of PVC pipes (except for the chest, made out of aluminum).

What's new in my process of making parts is that I used a 2 mm thick aluminum sheet for the main part of the body. But the technique was the same: metal ruler and sharp blade (and pliers to help break off the unwanted parts).

To give it a good finish, I have sanded it and end rubbed with steel wool. I used mask and gloves because the aluminum powder is irritating.

Electronics

The brain is an Arduino Mega 2560, with a sensor shield to facilitate the connections.

The power is provided by ten Ni-MH 2500mAh AA batteries. They are arranged in two packs of five batteries, and the packs are connected in parallel, which provides a total of 5000mAh @ 6V. To take some weight off of the body, some batteries were in the legs (two on each leg). Two batteries are inside of the chest.

Final notes: unfortunately the robot dog ended up not being able to walk, due to weak servomotors. But it was a good experience and gave me more know-how for the next iteration.

Below you see one more video of my robot dog "airwalking". :)