Pendulum - drawing animation with the aid of a light box

After what I thought would take me forever to complete, I created a moving pendulum by using a lightbox to help me draw the arc and plan the main key points of the animation. I first used a light blue pencil to help me to sketch out the arc of the pendulum and then roughly draw where the 25 points of the pendulum would go. (Using a blue pencil for rough sketches and drawing over the top with fineliner or pencil works well as the blue cannot be read when photocopying the work.)

I knew that the 1st, 7th, 13th, 19th and 25th points were the main key points, and I had to plan the inbetween points in such a way that it makes the pendulum slow down nearer the top of the arc and faster near the 7th and 19th mark.

Slowed down to see each individual frame

Normal speed

My attempt at the pendulum worked well through how the swing of the pendulum runs in an arc and gains speed as it swings back to point 7 and 19.
I found this task difficult but interesting at the same time, as I've essentially learnt part of the basics and want to experiment more with different movements.