Which of the following parts would a smaller, more inexpensive AM machine be best suited to produce?

A smaller, more inexpensive additive manufacturing (AM) machine is best suited for producing a conceptual model because these models typically do not require the same level of precision, material properties, or durability as functional prototypes or end-use parts. Conceptual models are primarily used for visual representation and concept validation, allowing designers or engineers to communicate ideas and designs without the need for advanced features found in more complex parts.

In contrast, functional prototypes usually demand higher accuracy and more robust materials, as they are intended to assess the functionality of a design before going into production. Production tooling involves creating molds or fixtures that need to be durable and precise, which would require more advanced machinery. End-use parts often must meet stringent performance standards and regulations, necessitating the use of high-end equipment capable of producing parts with specific mechanical properties.

With these requirements in mind, the cost-effectiveness and capability of smaller AM machines align perfectly with the needs of producing conceptual models, making them the most suitable choice in this context.