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Nostalgia, really -- I have fond associations of these with childhood train journeys. I could just about imagine a genuine use case in some kind of hostile env

Nostalgia, really -- I have fond associations of these with childhood train journeys. I could just about imagine a genuine use case in some kind of hostile environment. You could probably make one of these very resistant to water/temperature/radiation, with the controller kept safely out of the way.

argvargc 5y ago
That sparked an interesting idea: would these work in a zero-gravity situation (mechanically I mean), and if not, how to adapt them so they would? (And agree with the nostalgia - I'm sure for many the sound is associated with a quiet anticipation or excitement of embarking on a journey.)
- martin_a 5y ago
  They probably won't. After a flap has passed the upper lip, which is kind of holding it back to have a precise "flipping point", gravity will take care of moving it down. No gravity, no flap. ;-)
  - amelius 5y ago
    You could use suction or flow of air to overcome this. Or perhaps even a spring.
    - martin_a 5y ago
      Or just some kind of display that does not rely on gravity, yes.
- grishka 5y ago
  > how to adapt them so they would? Add rotary springs (is this a valid term?) to the flap hinges so they're forced down once released from the top edge of the frame.
- ridaj 5y ago
  I think they'll work... Somewhat? As the card is pushed through the face, there's a small amount of spring energy that it stores by bending, which gets released when it makes it through the opening and propels it forward + downwards. Normal gravity just adds to that motion and keeps the flap moving down. Zero g doesn't help as much but the card should already have momentum out of the gate. In zero g the problem may be more dealing with the rebound as the flap hits the bottom of the frame - it may bounce back up and float. May need some dampening or magnetic trick to keep it down... In any case they probably won't work upside down.
mjhagen 5y ago
I used to have one of these, but left it above the radiator. All flaps warped beyond repair :( So if you're going for resistance to harsh environments you'd have to source a better material for the flaps, at least.
- grishka 5y ago
  Hm, after watching and listening to videos of these displays at airports and train stations (don't think I've ever seen one in person), I thought the flaps in the commercial ones were made of thin sheet metal because the flipping sound was somewhat sharper than the OP version.

argvargc 5y ago

That sparked an interesting idea: would these work in a zero-gravity situation (mechanically I mean), and if not, how to adapt them so they would? (And agree with the nostalgia - I'm sure for many the sound is associated with a quiet anticipation or excitement of embarking on a journey.)

martin_a 5y ago
They probably won't. After a flap has passed the upper lip, which is kind of holding it back to have a precise "flipping point", gravity will take care of moving it down. No gravity, no flap. ;-)
- amelius 5y ago
  You could use suction or flow of air to overcome this. Or perhaps even a spring.
  - martin_a 5y ago
    Or just some kind of display that does not rely on gravity, yes.
grishka 5y ago
> how to adapt them so they would? Add rotary springs (is this a valid term?) to the flap hinges so they're forced down once released from the top edge of the frame.
ridaj 5y ago
I think they'll work... Somewhat? As the card is pushed through the face, there's a small amount of spring energy that it stores by bending, which gets released when it makes it through the opening and propels it forward + downwards. Normal gravity just adds to that motion and keeps the flap moving down. Zero g doesn't help as much but the card should already have momentum out of the gate. In zero g the problem may be more dealing with the rebound as the flap hits the bottom of the frame - it may bounce back up and float. May need some dampening or magnetic trick to keep it down... In any case they probably won't work upside down.

mjhagen 5y ago

I used to have one of these, but left it above the radiator. All flaps warped beyond repair :( So if you're going for resistance to harsh environments you'd have to source a better material for the flaps, at least.

grishka 5y ago
Hm, after watching and listening to videos of these displays at airports and train stations (don't think I've ever seen one in person), I thought the flaps in the commercial ones were made of thin sheet metal because the flipping sound was somewhat sharper than the OP version.