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The Staging Cone is designed to be able to attach by way of shear pins to the booster airframe and to the sustainer by a geometrical fit. The upper cone of the Staging Cone is to be the exact geometry (in the positive) of the sustainer nozzle (expansion section) so that is it sits properly with no tilt and such that the entire outer area inside the nozzle is in contact with the cone. This calls for fine, yet unspecified, tolerances.
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The main design change from Demo II is the that the Staging Cone (Phoenix) will be made in two separate pieces. This was done for the purpose of making machining faster and more practical. It may also have the unintended (but welcome) consequence of making the part cheaper. This is due to the fact that there is less material that has to be cut away since the smaller diameter cone is made from a separate piece of stock from the larger diameter base (booster airframe retention).
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- Take both stock and face both sides on the lathe
- Turn outer profile (for both)
- Bore our inner profile (for both)
- Use Radial Indexer on the mill to drill holes (in both)
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