grimthorpe's 4 legged gravity escapement in lego technic

[halnwheels]

I love watching this escapement in action but coming across this being done with a child's construction material! - I LOVE IT!

BRAVO!

[irkibby]

I'm a bellringer and I sometimes peer into the glass fronted clock case in the corner of the tower, looking at the Gravity escapement. I'm seriously impressed you managed to build one in lego!

[dan020350]

a large tower clock - i see, so that is what its called. :)

[ve2zzz]

This escapement is widely used in large tower clocks. One of it's main advantages is it's high isochronism. Because the added energy comes from the leg's weight and not main weight's impulsion, a change in the main weight (or in the geartrain's conditions (lube drying out for example)) has very little effect in the pendulum's amplitude (the main weight lifts the left and right arms. and THEN, these arms give impulse to the pendulum alternatively.

[Chironshands]

This is a nice design. Good job pulling it off in such a compact form.

[Builderboy2005]

it doesn't seem that it puts energy back into the pendulum, how does it keep going?

[horolophile]

As the pendulum swings to the right, it picks up the right gravity arm at a higher position than when the two part company on the return swing to the left. The height difference between the pick up and release points is the energy added to the pendulum. The same goes for the left gravity arm. When the pendulum picks up a gravity arm, it unlocks the escapement, which raises the other gravity arm back to its higher position, ready to be picked up by the pendulum on its next swing.