Here is a suggested beginner strategy for building your prototypes:
Focus on making your proof of concept first.
1. Buy a spiral notebook :
2. Label it “my invention name..”
3. Make a sketch with detailed diagrams and date the pages (spiral notebooks cannot lose the pages)
4. Make your proof of concept. You could also make a 3D model. They are great for augmented reality simulations and are often easily ported for 3D printing.(Keep a list on the side for things that your product ..must have…nice to have… definitely should NOT have. It will help tremendously when you have to trim the design. Which you always will, on multiple occasions.
a) To keep the costs down try and use up household items or things you can buy from the hardware store.
b) You can also have it 3D printed if you make the model digitally.
c) Many local libraries have a 3D printer than is either free or inexpensive to use.
There are a number of online services too if libraries do not offer 3D printing.
You3DIt.com is good for those who are not tech savvy.
Ponoko.com is another good one.
MakeXYZ.com isn’t a 3D printing service so much as it set you up with people with 3D printers in your area.
For more complicated prototypes make the pieces separately and assemble them after they’ve been printed.
GOOD LUCK WITH YOUR PROTOTYPES!