16.821 is a capstone class centered on building an aircraft. Many students learn a technique for layups through this class. Here, we'll break down that technique into several steps.
- Make a Mold
- Prep the Layup
- Do the Layup
Make a Mold
Not every layup requires a mold, but for some (like a nosecone layup or bulkhead layup), molds are very useful. They ensure that your part comes out the right size and shape, and also gives the part a beautiful surface finish if done properly! To make a mold:
- Buy some RenShape.
- RenShape is a dense, sturdy foam that is very easy to work with. Aluminum is a preferred mold material because it is harder and less porous than the foam. But, Renshape is cheaper, lighter, and easier to manufacture, especially when the mold becomes very large.
- 16.821 uses this type: https://www.freemansupply.com/products/machinable-media/renshape-modeling-and-styling-boards/renshape-440-styling-board
- Create a CAD model of what you want the mold to look like.
- Using the CAD model, route the shape into the RenShape.
- Sand the RenShape mold.
- It is important to be detail oriented in the next couple of steps.