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Design for Manufacturability
It is very important to consider how a part will be machined when designing it, even if you will be sending it out to be manufactured by somebody else. The design of a part has a direct influence on what machine tools and tooling is used to manufacture it. Poorly designed parts can be expensive to produce or sometimes impossible
Mill
- Design
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- the part to be machined in the fewest number of clampings possible
- Radii should usually be greater 1/8". A 1/8" end mill is a common small end mill size
- Features requiring an end mill longer than 4 times it's diameter are usually difficult to machine
- Fillet internal corners
- A boring bar can be used on the student shop manual mills to bore large diameter holes.
Water Jet
- Very quick and inexpensive way to make parts with simple 2D geometry
- Holes with important diameters should be undersized and drilled to size on the drill press
- For tapped holes can be tapped after cutting
- There is usually some draft on the cut edges
- The surface finish of the cut edges is usually quite rough but can be easily cleaned up with files
3D Printing
- The most practical application for 3D printing is to prototype injection moulded parts
- MS doesn't do any injection moulding but 3D printing can still be of use to us where a plastics might be used on a real car or where complex geometry is required but strength is not important
- FDM 3D prints have orthotropic tensile strength
- You can use heat set inserts or helicoils to put tapped holes into plastic parts
Welding
Fits
Press Fits
A good rule of thumb for a press fit diametral interference is 1/1000th of the diameter you are trying to fit. So if you have 10mm shaft,