Introduction: Lego Hexapod
The hexapod consists of three piers with a pair of legs on each one.
Every pier has an oscillatory motion that makes the legs go up and down as well as move back and forth alternately.
Step 1: This Is Everything You Are Going to Need
Step 2: The Piers
First step is to build a camshaft supplying the oscillatory motion to each pier. This is mounted on the support shaft and a perforated bar is used to give motion to the legs.
On each side of the pier, an articulated leg is set on the side supports, in such way it moves back and forth depending on the lateral displacement of the perforated bar.
Step 3: Putting Them Together
Piers central shaft and camshaft are fixed together using L shaped bars. In case of central pier, pinions are also installed to give movement coordination.
Then all the piers are put together, connected by the central shaft and camshaft, given that the lateral axes of the camshaft should be alternated.
On the whole device end, additional pinnions are added to improve coordination.
Step 4: The Geardrive
I have a PF Medium motor which runs pretty fast (about 400rpm) so it needs to be reduced, with the added benefit of increasing torque significantly.
In this case I set a 4 step cascade and the lower shaft on the picture will be the one delivering movement to our hexapod central shaft.
The gearbox is set between central L shaped bars, using the final shaft as pin point and an additional rod to keep it from turning around itself.
The bottom shaft receives the pinnion connecting the gearbox with the central shaft. Bushings must be used to avoid axial movement of pinnions.
Step 5: On Your Mark, Get Set, Go!
On top of gearbox there is a shaft, where the PF motor must be installed and secured using pins. Our Hexapod is ready to walk around the house and scare the cat. If you don't enjoy the company of a housepet, fun is limited to less than half.