...Mas, FAÇAM QUALQUER COISA, PÁ!

Não, não há mais desculpa para não fazerem o que vos der na cabeça, não quando é tão fácil quanto ISTO, 2 Molduras, material de Escritório, o forno e o Aspirador lá de casa...

E quererem fazer ALGO! 
Quanto aos Moldes, só precisam de um por ideia, e podem bem ir fazê-los à FabLab mais à mão... 

Make a good, cheap, upgradeable sheet plastic vacuum formerdrcrash Tired of buying cheap plastic crap? Now you can make your own!
Or you can make nice and surprisingly sturdy plastic stuff in amazing shapes, amaze your friends with your technical prowess, and be the life of the party.Vacuum forming is a technique for shaping sheet plastics into 3D shapes, which you can do at home, easily and cheaply. And it's fun. It's the easiest way to make an infinite variety of shapes in plastic, or to make molds for casting shapes in other materials, such as concrete.The basic technique is to0. clamp a sheet of plastic to a frame (such as a windowscreen-type aluminum frame)1. heat it in an oven (such as your kitchen oven) until it's soft and rubbery2. stretch it over a convex mold of an interesting shape (such as a life cast of your sweetie's face), and 3. suck the plastic inward onto that mold with a vacuum system (such as your household vacuum cleaner)Once the plastic cools, you pull it off the mold and trim off the excess plastic, leaving a copy of whatever shape you sucked the plastic onto.  http://www.instructables.com/id/Make-a-good%2c-cheap%2c-upgradeable-sheet-plastic-vacu/

Ou querem fazer uma Impressora 3D, super-barata, com Sucata? Pois cá está como é, passo-a-passo, com CDs e DVDs que encontrem por aí, e pouco mais:

 

Complete newbie step by step, 3D printer with all parts listsdintid  
Intro, prelude, or just: who is this meant for?I wanted the title to include cheap, but lets face it: it is not cheap to build a 3D printer unless you have some/most of the components on hand or if you find just shy of £100 as cheap to make a tiny, not very good quality printer. This tutorial is all about starting from zero, figuring out and understanding all parts of a 3D printer and keeping costs down for this our very first build.
The upside is that all the items can be reused for a larger better printer at a later stage. I did that, and it Works wonderfully - better than an Ultimaker original in fact (proud).
It should be obvious which one is made from old CD/DVD drives, and which one I reused my parts in later :) I opted for a small printer, but you can just ordre longer metal rods and get a larger cabinet, and you have a larger printer at the same cost.
I have not kept strict tabs on costs, but the final printer, which is awesome, amounted to a total of just over £200 or so.
In short, I'm going to build a 3D printer made from parts from old CD/DVD drives and some aluminium pieces. I am going to provide complete detailed description on every single part needed. There will be no requirments on having advanced or expensive tools nor expert knowledge on anything.

http://www.instructables.com/id/Complete-newbie-step-by-step-3D-printer-with-all-p/  

 

...E se não, esta Fresa CNC resolve-vos o problema, lá está, mais um Projecto que só não faz, quem não quizer:

How to Make a Three Axis CNC Machine (Cheaply and Easily)oomlout 
The idea behind this Instructable was to fulfill my desire for a desktop sized CNC machine. While it would have been nice to purchase an off the shelf unit the issue of price as well as size proved prohibitive. With this in mind I endeavored to design and build a three axis CNC machine with the following factors in mind:
-Use Simple tools (needs only a drill press, band saw, and hand tools)
-Low Cost (this kind of got away from me however with everything bought off the shelf the cost for all parts is under $600 (significant savings could be made by skillfully sourcing some pieces))
-Small footprint (30" x 25" footprint)
-Usable working envelope (10" X-axis, 14" Y-Axis, 4" Z-Axis)
-Relativly fast cut rate (60" per minute)
-Small part count (fewer than 30 unique parts)
-Easy to source parts (all parts available from 4 sources (Home Depot + 3 online sources)
-Ability to cut ply-wood (Succesful)

http://www.instructables.com/id/How-to-Make-a-Three-Axis-CNC-Machine-Cheaply-and-/