Very simple:

You need, a stepper motor.
a 3d printer
those 2 printed parts.
an android cell phone (or tablet)
a line laser, like:

http://www.ebay.ca/itm/650nm-5mW-Red-Laser-Line-Module-Focus-Adjustable-Laser-Head-5V-good-/381374426229?hash=item58cbafec75

Download and install this app: scan3doid (around 5$)

https://play.google.com/store/apps/details?id=com.gsohler.scan3droid&hl=fr_CA

Then I suggest unplugging x motor from your 3d printer and plug your new scanner's one.

Or, you can also prepare a parallel plug so that when you install the scanner, both the x motor and the scanner motor will move at the same time.

Now you have to determine how many "x mm" makes a complete revolution of the stepper. To do it, I used pronterface and counted the number of mm +1 before one complete revolution. for me it was 40mm.

Then send G92 X0, This sets, x to zero, without the need of hitting the end stop.

Then send a command G1 X40 F20

the x is the number you just determined earlier. and the f is the speed... If it goes too fast or too slow, play with it.

The best is when it makes a complete revolution in 50-55 sec.

Install the camera lens just where the arrow points: it makes a nice 30 deg between laser and camera. I suggest using a heat gun to shape the cellphone support to your cell phone.

When you are ready, use the app to record video and follow the instructions of the app.

The app is not perfect, but it works. I then had to make little "cleaning, but you can see the shape of the toy I scanned.

I've put an original stl file direct from the app.