Even though the projects design had to be greatly modified from its original 3 window design a I am really happy with how well the project has turned out and with all of the really positive responses I have got from other students and teachers. Without any more words here is the project.

Just in-case you haven't read my previous posts from way back about what the donation box actually is, here is a quick summary.

When somebody puts a coin into the machine it is sorted by currency and depending on the value of the coin a certain number of marbles are sent though a marble run (i decided on the rate of 1 marble per 10c). The idea of the project is that if it is made more interesting for people to donate then people are much more likely to make a contribution.

To better display this here is a video of the project in action

Also thanks to MWandel of woodgears.ca for his gear template generator and general articles on marble machines that made me pick this as a project

After i finish up with UNI preferences and scholarship applications i will hopefully have some more info up on what goes on behind the project

Edit: I now have another post up detailing some of the inner workings of the project HERE

Edit: If you are interested on more details on the construction of this project i have now made my portfolio available HERE.

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The project consisted of:

• Building a turntable to be controlled by the computer that can rotate the object accurately
• Convert a laser pointer to emit a line onto the object rather than a dot
• Have some way to take pictures of the position of the laser line on the object
• Write programs to control the turntable, find and process the laser line in the captured images and display the processed information as a 3d model

Here is a picture of the general setup I ended up using (I didn't get a good photo of the new stepper and gearing I got to rotate the object)

In this image you can see the turntable (black circle), the laser pointer being refracted into a line using the glass rod in the top right, the circuit board used to control the motor, and the board used as a quick way to trigger the camera.

Here are some images from the different stages of the process:

The object to be scanned

The object sits on the turntable and is rotated accurately using a stepper motor. The first stepper I used allowed 98 steps per revolution (the scan you can see below) while the second stepper motor I used had extra gearing and allowed 290 steps per revolution.

The hardest stage in the entire project is the extraction of an exact line from the image. The stages of this are:

1. Load the raw image
2. Extract the Red channel out of the RGB image
3. Find the entire line in this image as a 2 bit image
4. Decide upon an exact line through the previous blob ignoring noise

Coordinates are calculated for each point using how high in the image each point on the line is, what rotation the table was at in the image and some basic trigonometry to create thousands of data points that are then linked and covered with faces by a blender script to create a model.

The Raw Model

Then I have simply manually tidied up the model removing where the table appears in the scan and smoothing it.

Trimmed and smoothed

Then I have applied a stock wood texture to the model to produce the final result. I think that it has turned out rather well for a first go at creating a 3D scanner especially as it only took a few weeks and cost me nothing.

The finished product

I am happy to answer any questions you might have and last of all if you are still curious here are some of the sheets I handed in with my folio to show how the points were converted after extraction.

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