Many HCI fabrication systems are compelling as prototypes but remain difficult to reuse, extend, or transfer beyond their original publication. A common explanation is that adoption simply takes time. We argue that the issue is more fundamental. The knowledge needed to make fabrication systems transferable, namely how they behave across different materials, machines, and users, usually does not exist at the time of publication because the work required to generate this knowledge is rarely incentivized or rewarded. Drawing on engineering epistemology and prior debates in systems-oriented HCI, we reframe engineering maturity as epistemic work: sustained engineering effort that produces knowledge which prototyping alone cannot reveal. We propose six dimensions, Fab-ilities, as a vocabulary to describe what aspects of fabrication artifacts have become established and what knowledge remains tacit: (1) buildability, (2) executability, (3) reliability, (4) maintainability, (5) transferability, and (6) scalability. We describe five of our own projects (JigFab, StoryStick++, Silicone Devices, LamiFold, and PaperPulse), where varied attempts at dissemination, such as commercialization, spin-offs, and market exploration, each exposed different gaps between what we published and what transfer actually required.

Industrial assembly is shifting toward human-robot collaboration (HRC) to leverage the complementary strengths of both agents. However, traditional task allocation referred to as the Robotic Assembly Line Balancing Problem (RALBP) remains labor-intensive and often lacks transparency. We introduce DELEGACT, a framework designed to produce workable, intelligible human-cobot task allocations. The framework uses a Vision-Language Model (VLM) to extract atomic operations from expert demonstration videos, then employs a Large Language Model (LLM) to delegate these tasks based on robot specifications, operator competencies, and material definitions. We provide a proof-of-concept prototype and preliminary testing on illustrative cases. Results demonstrate the system's ability to reason about complex constraints such as precision, weight, and ergonomics. This paper illustrates how off-the-shelf foundation models can automate HRC decision-making via a human-in-the-loop paradigm while preserving operator agency and understanding.

Delays in direct teleoperation decouple operator input from robot feedback. We frame this not as a unitary problem but as three facets of operator uncertainty: (1) communication, when commands take effect, (2) trajectory, how inputs map to motion, and (3) environmental, how external factors alter outcomes. We externalized each facet through predictive visualizations: Network, Path, and Envelope. In a controlled study with 24 participants (novices in telerobotics) navigating a simulated robot under a fixed 2.56s round-trip delay, we compared these visualizations against a delayed-video baseline. Path significantly shortened task time, lowered perceived cognitive load, and reduced reliance on reactive "move-and-wait" behavior. Envelope lowered cognitive load but did not significantly reduce reactive behavior or improve performance, while Network had no measurable effect. These results indicate that predictive support is effective only when trajectory uncertainty is externalized, enabling operators to move from reactive to more proactive control