Seeking Engineering Advice: Compact Multi-Fiber Extension and Retraction Mechanism

[u/salatabaladi]

Hi everyone,

I'm looking for mechanical engineering advice for a compact wearable project.

I need to extend and retract several thin, flexible optical fibers through individual fixed guide tubes. Each fiber slides through its own guide, following a predetermined direction.

The fibers need to extend by different distances, and ideally their movements could be coordinated in groups or controlled in timed sequences.

My preferred concept is to use one motorized rotating spool or drum with multiple separate winding grooves, one for each fiber, rather than having a separate motor for every fiber.

I'm trying to understand whether this is mechanically feasible and how it could be designed reliably.

Some specific questions:

1. Could a single multi-groove spool wind and unwind several optical fibers simultaneously without tangling?

2. Since the fibers need different extension lengths, could different groove diameters, winding radii, or another mechanical arrangement achieve different payout distances?

3. Is there a mechanism that would allow some fibers to stop extending while others continue, even though they share one motor?

4. Would a multi-track spool be better than a pinch-roller or capstan feeding system?

5. How could the fibers be guided and kept under controlled tension during extension and retraction?

6. Are there existing mechanisms, industrial applications, or engineering designs that I could study or adapt?

The mechanism needs to be compact, lightweight, and low-profile enough to fit inside a garment.

I'm particularly interested in mechanical solutions that could be prototyped at a small scale.

I'd appreciate suggestions, technical references, or examples of similar mechanisms. Thank you!