When designing gears, there are many parameters that can affect the size. This push is enough to keep the pendulum swinging. The lever is designed so that as it is moving out of the escape gear, the gear gives it a little push. This causes the clock gears to stop and start rotating every second. As the pendulum swings back and forth, it rotates the escape lever in and out of the escape gear. Many pendulum clocks have the escape gear on the second hand axle. It will make one rotation every 60 seconds. Since our escape lever will have 2 teeth, one to stop the escape gear at each end of the pendulum swing, our pendulum will need to have 30 teeth. For a period of 2 seconds we need it to have a length of 1 meter. If the period is 2 seconds, this will basically make the escape gear our second hand since it is rotating one tooth every second. With each swing the escapement will allow the escape gear to turn one tooth at a time. That way, it will take the pendulum 1 second to swing to one side. For our clock, we want to have a period of 2 seconds.
If you have too heavy of a weight, you will not have enough energy to keep it swinging. As we will see next, the escapement helps give the pendulum a push. This is helpful because we want to keep the pendulum swinging. So the pendulum with the 5 pound weight will swing for a longer amount of time, than the 2 pound weight. The weight at the end of the pendulum does affect how many times the pendulum will swing. So, if you had a 2 foot long pendulum with a 5 pound weight, pulled to the right at 90 degrees, it would take the same amount of time to swing across and back as a 2 foot long pendulum with 2 pounds of weight pulled to the right at 30 degrees.
The neat thing about pendulums is that this time, or period, is not dependent on the amount of weight or length of arc, it's dependent on the length of the pendulum. The period of a pendulum is the time it takes to go from one side to the other and back again. They are a weight at the end of a string or pole, with a pivot at the opposite end of the weight. This allows the energy of the weight to be spread over a period of time so you are not winding the clock every 2 minutes. The pendulum swings back and forth moving the escapement lever in and out of the escape gear, causing the gear to stop spinning. The escapement is built out of the escape gear, escape lever, and the pendulum. This escape mechanism also creates the "Tick Tock" that you hear from clocks. From the word escape, it allows the energy of the weight to escape in a slow manner, as to not use up the energy at once.
We need some way to allow this energy to escape slowly. If it is placed on the hour hand, you can easily get by with winding once a day. The farther down on the gear train, the slower it will unwind. You want it farther down the gear train so you aren't winding the clock every 4 hours.
Placement of the weight and cord is a little critical. This isn't very practical unless you want to pretend you are in a time machine. If this was just the weight and gears, when the weight was released, the gears would spin for a few seconds and the weight would hit the floor. As it pulls down, it rotates the gears causing the minute and hour hands to rotate. The weight is wound around one of the axles. It uses a weight as the energy source, and a pendulum to regulate how fast this energy escapes. These have been in existance since the mid 1600's. The clock I have designed is a basic pendulum clock.