Tuesday, June 12, 2012

Three servo walking robot, shifts weight/legs, feet rotate body forward

Found on Makezine.com: http://blog.makezine.com/2011/10/20/how-to-three-servos-walking-robot-video/

This robot is from a how-to on Let's Make Robots by Frits Lyneborg. It is a simple walker that has a nice design. Often walking robots can be quite complex.

There are three servo motors: two for the feet and one at the hips that shifts the weight and position of the legs. There is a four bar linkage in the "leg area" that lifts one leg up at a time. The side bars are the legs, which also hold the servos for the feet. The upper, normally horizontal bar has a high stick with the battery pack, so that when bar is slanted the weight is tipped to one side, which helps the walking movement. While standing on one foot, the foot servo rotates so that the body swings forward. The basic idea is like when you "walk" a large object, like a big board or piece of plywood, by tipping it a little on a corner and swinging the other corner forward, then repeat by alternating the corners.

The creator also uses paint mixing sticks and hot glue, which is simple and works great. He hot glues symmetrical pieces together so that any drilled holes will line up exactly. Then he cracks them apart. The microcontroller is just a simple Picaxe.

Alarm clock project: landing page

This is a landing page for my alarm clock project. There are three posts on this project, so I though it would be helpful to have one overview page that I can direct people to.

I have a cheap plastic alarm clock that had small buttons, specifically the alarm off button. So I wanted to replace them and mount bigger buttons (I added a big snooze button too). I used Adafruit's small and simple arcade buttons (which I've described in this informative post, in case you want to know about them for your project) and wired them to the button contacts on the inside. I took out the CD player to make room for the buttons cut holes in the top to mount them. It turned out great in the end.

First post: initial opening and beginning research
Second post: cutting
Third post: installing buttons and final look

Finished project

What it looks like inside.