The escapement wheel was machined from Aluminium plate and press fit to a brass hub. A torque load is appled to the wheel via a spool, line and weight in the rear side of the supporting post. The wheel is 70mm in diameter and has 9 teeth. The rocking arm has 4mm diameter pins that engage the wheel. The rocker arm swings plus/minus 10 degrees and the wheel provides the travel limit. The top of the rocking arm is 40mm from the pivot and the two lugs have a gap of 30mm. A 29mm wide block attached to the rear face of the pendulum contacts the lugs to flip the rocking arm and allows the pendulum to swing freely, clearing the lower lug by about 0.5mm. The leading edge of the escapement wheel teeth have a profile to provide a small torque to the rocking arm driving the engaged pin towards the wheel. The slope on the top of the teeth kicks the pin when it is released by the pendulum and the rocking arm transfers some of that energy to the pendulum. All of the bearings are brass bushes, pressed into the post. The friction losses here are significant.
In full swing [QuickTime(23MB)] ... and at full volume.
The weight has a small pulley with a 9x5x3mm bearing.
The sensor that will eventually measure the pendulum's state (left or right).