Cal Poly ACS: Why Are Reaction Wheels Angled at 29.3 Degrees?

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The discussion centers on the design choice of Cal Poly's ACS, specifically the 29.3-degree angle of each reaction wheel. The angle may be intended to optimize performance by aligning the wheels with the center of mass (CoM). Participants express concerns about having too many reaction wheels, as redundancy can add unnecessary weight. A proposed solution involves creatively positioning the wheels on the edges of a triangular pyramid to maintain redundancy without increasing weight significantly. The conversation highlights the balance between effective design and weight management in spacecraft systems.
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Here is a link to Cal Polys ACS they built. My question is: they claim each reaction wheel is angled at 29.3 degrees. Why would that be? My only guess is that they are each pointed at the CoM.
 
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You certainly don't want three reaction wheels (one per axis). What if one fails? You certainly don't want six (two per axis), either. Too much weight. One way to get redundancy at a minimal cost is to get a bit creative in the layout, arranging the reaction wheels on the edges of the triangular faces of a right square pyramid.
 
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