Pop-Up Hydration Reminder Mechanism

I’m developing a reusable water bottle that physically reminds its owner to take a sip every hour. The cue I want is simple and visual: a small flag should rise from the lid when it’s time to drink and drop back down once the bottle is lifted or the cap is reset.

I need a mechanical concept that can live entirely inside (or be integrated into) the bottle cap without relying on batteries, electronics, or external apps. Think clock-work, torsion springs, cam drives, or any passive timing solution that can reliably cycle every 60 minutes as long as the bottle is upright.

Here’s what I’d like from you:
• A clear explanation of the working principle, including sketches or diagrams that show how the hourly timing is achieved and how the flag deploys and retracts.
• 3-D CAD files (STEP or SolidWorks preferred) of the mechanism sized for a standard 60 mm cap footprint.
• A short parts list with off-the-shelf components wherever possible, plus notes on tolerances and food-safe materials.
• Assembly/usage notes so a prototyping shop can build and test it without guesswork.

The mechanism should be sturdy enough for daily use, easy to hand-wash, and manufacturable via common methods such as injection molding or sintered metal for springs.

If you’ve designed small mechanical timers, pop-up indicators, or similar consumer-product mechanisms before, I’d love to see examples. Let’s create a bottle that nudges people to stay hydrated—no electronics required.