Intro: Ikea Robotics : Moving Table
* I am attempting to recreate this project in it's entirety, but have not located all associated files. I will update this as I find them. The project consisted of a table and a chair. I will begin with instructions for the table and follow up with a chair Instructable.
This project began as an exploration of dynamic architecture but evolved more into a study of "living" furniture, and how it would feel to have furniture in our homes that had lives of their own.
I chose Ikea because it is engineered well, but made cheaply; so it is somewhat valueless after a person is done using it. So I had no qualms about cutting it apart and shoving a bunch of electronics into it. Also the hollow structure of many of the pieces make it very amenable to structural modification.
Step 1: Table Dissection and Concept
The goal when modifying these pieces was to conceal the technology and maintain the existing lines in the design of the pieces. This is essential as I wanted the users to perceive the objects as furniture, rather than a chair sitting on a mobile platform.
The first step when building this was to investigate the structure of the table. The MO of Ikea seems to be to get the as much structure as possible out of as little material as possible. This allows pieces to be cheap and light, but that means that they also don't age well. As you can see above, the table has reinforced edges of particle board with a largely hollow center. The hollow parts are strengthened with a honeycomb of paper. The legs are also hollow, reinforced at the ends with particle board. This allows the structure to support the hardware that joins the legs to the body.
Step 2: Mechanical Architecture
The illustration above describes the basic architecture of this system:
A single stepper motor rotates the four legs at the same time, ensuring that they all point in the same direction. This "all wheel steering" method allows the table to move in any direction without rotating.
Each leg is powered by a single motor which is always driven in the same direction. (In my prototype, I only drive two of the four legs and the other two turn free). In this way, the table can immediately drive in any direction desired. However it also means that the table cannot rotate, as the wheels must always turn in the same direction.
Step 3: Leg Fabrication: Rotating Shaft
The first step is to prepare the legs to be attached to the body:
If the threaded stud has been inserted into the ends of the table legs, it should be removed. A 1/4" hole is drilled through the particle board at the end that joins the table body. The particle board piece that caps the opposite end is removed completely.
A 1/4" bolt is dropped through the hollow end, through the 1/4" hole. A flange bearing is fixed to the end of the leg with a lock bolt. So we now have a threaded shaft fixed to the leg rotation, and a flanged bearing that will allow this entire assembly to rotate against the flange.
Step 4: Laser Cut Components
The only custom fabrication piece here are the laser cut mounts for the stepper motor driving the steering, the wheels mounts, and the joint where the legs connect to the body.
These pieces could also be 3D printed, or just fabricated by hand. In any case, their purpose is to reinforce the important parts of the body.
Step 5: Leg Fabrication : Attaching Wheels and Motors