How to make a scale model based on a 3d file

There is several methods to make a real life model based on a 3d file, such as 3d printing or milling. Most of them are expensive, very expensive. You need either to own one of these machines or outsource your work to someone who own one.
But there is also an other method that everyone can perform without any special tools or machine and here is how I do.

First of all, I stretch my 3d model into the scale I want it to be :

 

Then draw a section every X inch/mm depending on the material that you decide to use for your scale model.

In my case, I decided to use a 5mm thick foam board (3$) for my sections for a final size/length of the model about 11 inches.

 

Once the sections plans are defined, I drew the intersections with the volume, then a 5mm thick extrusion of each profile just as it will be in real life cut foam board sections.

 

Then I make a drawing of each volume section. Each drawing is sent to a normal printer. On each drawing I add a 2 inches vertical and horizontal scale to check, after printing, if there is no image deformation.

Then I cut these shapes, glue them on the foam board (spray photo glue) , and cut the foam with a X-Acto cutter. After cutting and assembly, this is how it looks like :

 

 

 

After cutting....

The next step consists into using a clay on this shape in order to make it smooth.

I tried different kind of clay but the one I really recommend is the "light weight stone clay" (Padico/LaDoll "Premier" ~10$). First of all, it is compatible with paper and foam. It sticks perfectly with these materials without melting them down. It's also very light (feels like paper on the fingers), easy to work with, not oily, not wet ad don't stick too much to fingers.

After a first clay application, this is how the model look like :

Then it's time for sanding...

Nota : I use regular 100 sandpaper and also a Dremel micro drill for some parts.

After a first sanding this is the model.

You can notice that there is still a lot of small imperfections, like holes. The clay that I use allows to put it again and again, even in a thin layer. Basically this part of the work consists in sanding, then finding the defaults, adding some clay, then sanding again, and repeating this as many times as necessary until obtaining a perfect result.

By the way, the method I use here for a small scale model can be used for any scale shape building (even a full size one). The only differences may be in the materials used.

(to be continued...) :)