LEGO Clock Escapements

I've decided to rebuild my LEGO clock and have begun playing with newer improved escapement mechanisms. I'm aiming for a 1 second period for the pendulum, which would allow me to put a second hand on the clock that actually moves once per second.

There are 5 escapement mechanisms in the video. For the final assembly I'm leaning toward either the 8 tooth (second version) or 12 tooth escapement. While the 24 tooth escapement is tempting to use, it's very finicky and difficult to get running efficiently.

Thanks to BenVanDeWaal for inspiration.

Category:

Science & Technology

Tags:

• LEGO
• clock
• escapement
• pendulum

[Error383]

Thanks for the 24 teeth-escapement idea. I have improved it further, resulting in a clock that runs for about 4 days, using a 2L bottle going down for about 1,2 meters.

:)

[sforbs]

@Error383 Cool! I'd love to see how you did it, it sounds like a very efficient set up.

[BenVanDeWaal]

(contnd) at the moment of impulstransfer; it looks like an (adjustable?) sandwich of three thin plates. My 2nd question is: where is the locking lever resting on and rotating about? It must have a hole, but seems rather thin. Is this a genuine Lego part?

Kind regards,

Ben.

[sforbs]

@BenVanDeWaal

Thanks! To get things adjusted just right, I used some odd little pieces to change the shape/location of the contact point on the pendulum. These were different for each mechanism, some adjustable (mechanism #2, #4, and #5) and some not adjustable (#1, #3)

I used part 32028 on mechanisms #1 and #5 to make the arm on the pendulum the right length. Mechanisms #2 and #4 use part 3794 with a "tile" piece on top that can be adjusted

The part supporting the locking lever is part 2817.

[Error383]

@sforbs Yeah, i used an edged suspension using a knife and i kinda cheated by using a 64 tooth wheel i found in some other machine that fitted on my lego as well! The major improvement was the locker though. It ruins you efficiëncy if it isn't proper designed, so improving that dramaticly affects your running time. I'll might make a video of it :)

[KEvronista]

@killerbeenl

d'oh! no, the larger diameter offers less leverage than the smaller. the 24t gear is the ideal scape wheel.

KEvron

[KEvronista]

@killerbeenl

....now it occurs to me that, while the 40t is substantially heavier than the 24t, it offers greater impulse leverage due to its larger diameter, as well as the extended duration. it's a toss up that can only be resolved through experimentation. maybe i'll undertake....

KEvron

[KEvronista]

finally got around to building my own version of the 24t escapement. the thing's a juggernaut! i started to mimic, more or less, your own design when it occured to me that i could achieve greater leverage from the escape wheel by extending the length of the impulse arm. i've also got it designed so that the wheel spins in the opposite direction. i don't think i'll ever design with anchors again.

KEvron

[KEvronista]

@killerbeenl

....so, i've been doing some homework. according to bricklink's catalog, a 40t gear weighs 3.76 grams, while a 24t crown gear weighs a mere 1.1 grams. the 40t offers 67% more duration, but at a cost of more than 300% in weight. axle friction accounts for a good portion of the drive train torque, but ultimately, it's the weight of the escape wheel that accounts for most of the torque demand. in short, it seems the 24t crown gear is actually the ideal escape wheel.

KEvron

[KEvronista]

@killerbeenl

yeah, i figured the angle of attack would be an issue. i've devised an anchor escapement for the 40t gear, in which i use the tiny 1x1 slopes (peeron part #50746) as the pallets. they might be useful in resolving your design.

KEvron

[killerbeenl]

@KEvronista The angle on the 40th tooth wheel, then i mean between the teeth makes it almost impossible to make a gripping/ stopping mechanism on it. I've tried it a lot because it would be ideal 40 seconds times 2/3 is 1 min exactly.

[KEvronista]

with which of these escapements do you intend to build your clock? the 24t would seem to be the ideal choice, but i imagine it may be more problematic in practice than the others. any luck with a 40t gear?

KEvron