Construction of babycloud and related images


Balsa wood

I used 2mm, 3mm, 5mm and 10mm balsa wood for the various parts of the robot body. To make the corners, I soaked in hot water 2mm and 3mm balsa wood and let them dry in the sun. Initially I wanted to make bigwheels out of balsa but it was impossible to make a good hub to attach them to the motor.

Motor, wheels and workarea

The hub needs to be perfectly aligned to the motor shaft, and since I couldn't make one I bought this Tamiya narrow tire set. The work table as it looked like sometime in july 2006 while working on the initial body design. Assembling the first robot body. Yes, ok, I admit it; a workarea is never that arranged during work.

Making the robot body, first design

A top view. I liked the layout of the different components. Side view. At that time, I had no wheels. This was a critical mistake as you can see bellow. Rear side. A toggle switch controls the line following function; a dark or light coloured line to follow.

And destroying it

Bottom side. Between the motors and the switches I have constructed a battery holder for two 9V batteries. Guess what. Motors should be lowered to accept the wheels I bought or they will never reach the ground. It's ok... I only had to redo the whole thing. Bugger! Since I hadn't learned any electronics CAD program yet, I printed this layout and drew the circuit by hand. It wasn't too hard. Really!

Circuit board and construction of the new robot body

The circuit board complete. You can see a LM393, NE555, 4017 and a 7806 voltage regulator. Preparing the parts for the new robot body design. Assembling the main compartment.

Adding the sensors and the switches. The rear side. The bottom side. Batteries are held into position with the help of a balsa piece and a pair of screws.

The back side. The pushbutton turns on/off the hood lights. LEDs show when sensors are balanced over a line. A general view of the finished lower body. Bottom view.

Sensor bracket painted black to keep ambient light from reaching the sensors. Bottom side covered with thin balsa wood. Notice the thick coat hanger wire. Minimal surface contact for low drag. A view of the LEDs under the hood. I didn't pay much attention on how to optimally arrange them.

Making a track and testing the robot

The track. Outer dimensions are 150x140cm. Line width 4cm. A photo taken during a test run with a voltage regulator on a solderless breadboard. You can see a small video during the testing phase.

Experimentation with a homemade caster wheel and hood construction

I first wanted to make a caster wheel to support the back side but it didn't last long. If I had replaced the ABS plastic arm with a wire it would have been perfect but that idea came too late... This is the balsa wood construction that rests on top of the robot and supports the wax hood. Trying to make a wax hood... Not a cloud shape on this one. But it does look interesting!

I poured melted wax on a homemade container and waited to get cold enough. I then worked it with my hands to form a shape I like. Only small pieces can be worked by hand at a time because the wax deforms and collapses under its own weight. Different color combinations would make it look neater. Unfortunately, after I put on the central cover the whole hood lowered too much to be useful. I hated to redo it, so I didn't.

That was the color of the central cover. The trick with that pool of wax is that you need to make the whole surface have the same depth (about 2-3mm) witch is harder as the area gets bigger and bigger. The final configuration I worked with. I made a large container and when it was cold enough I placed it over the paper construction covering it completely. Then let it cool.

   
And when it was rock solid, I removed piece by piece the paper inside. After that it was ready to be placed on the robot body.