| First, I’d like to apologize to the community for my clumsy entrance — I probably came across like a drunk guy stumbling into a party he doesn’t yet understand. I should have spent more time learning the community norms first. That said, let me try to respond to your very insightful and constructive questions. At this scale, water tends to replace the air film and introduce surface tension and capillary forces between the ball and raceway. That adds drag rather than reducing friction, especially when combined with fine particles or residue. So your concern is absolutely valid. Our honest answer is that we’re constantly balancing real-world usability against technical constraints. We did consider applying hydrophobic coatings to the raceway, but in practice those coatings wear off very quickly at the actual contact points inside the bearing, which makes them ineffective over time. Instead, we focused on making the internal structural components corrosion-resistant and water-tolerant, and designed the system so that, rather than trying to completely block water from entering, it can be easily cleaned and quickly dried. The “sticky” or sluggish feel water introduces in a micro-bearing is temporary. In practice, you can restore normal performance by blowing it dry with a hair dryer in about a minute. The analogy we often use is washing your hair: if you’re not in a hurry, it will air-dry on its own. If you need to go to sleep right away, you use a hair dryer. In either case, the impact on the overall experience is minimal. By the way give me a bit of time — I promise I’ll put together a more systematic report with photos and data from our testing. There’s no real secret sauce here, just a lot of trial, error, and tiny tolerances. |
Usually more technical post get better traction, so if you have some interesting side quest building the device, it may be better. But it must be interesting. What is your favorite anecdote about building the device to tell to your fiends over a beer? (Bonus points if it's a technical friend.)
Some ideas from https://www.youtube.com/@Clickspring . But the guy is extremely good so it's a very high bar, it's not necessary to be as good as this guy to post here. (Anyway, I prefer a blog post with photos than a video.)
If you have two accounts, you can ask hn@ycombinator.com about how to merge them, or perhaps they will tell you to just use one of them and never use the other again.