Swing a Pendulum
By: Bill Dilworth
Date Created: February 14th 2006
Last Updated: March 2nd 2009
Bill Dilworth admits that "cutting-edge", when he was in high school,
was "two teletype machines with an acoustic modem link
to the University of Delaware's mainframe". Anyone remember
yellow punch tape?
Bill's mostly picked up PowerPoint on his own, doing occasional presentations at work and helping co-workers solve their computer problems. But he really hit his stride when his wife volunteered him for the post of Tech Team Leader at their church, where he's applied his PowerPoint and theatrical knowledge to the fullest.
Creating a pendulum swing animation is possible using PowerPoint 2002 or later - and involves creating a hidden pivot point. A pendulum (the real type) swings back and forth on a pivot point at the top of the weight's string, so we will need to create a shape that appears to swing at the end of a string and repeats back and forth from this pivot point. Here are the steps:
You can download the sample presentation here... (around 4 kb)
- Create a new presentation (Ctrl + N) and insert a blank slide.
Or insert a blank slide in an existing presentation.
- Choose the line tool in the Drawing toolbar and create a
standing line from the pivot point to the weight in its far bottom
(as shown in Figure 1). Start drawing from the center of the
slide, and hold the Shift key while dragging and drawing
the line so that you end with a perfect,
- Double click the line, or select the line and choose Format
| AutoShape. Either way you'll get to the Format AutoShape
dialog box - in the Size tab, change the Rotation value to 22.5° (see Figure 2).
Click OK to exit the dialog box.
- Draw a circle beneath the line - and change
the line thickness and color for both the line and circle as
required. Select both the line and the circle and right-click
the selection - in the fly-out menu choose Grouping | Group.
Your slide should have a pendulum swinging towards the left as shown in Figure 3.
- Select the pendulum and duplicate it (Ctrl +
D) - now select the duplicated pendulum and choose Draw (in the
Drawing toolbar) | Rotate or Flip | Rotate Left 90° (see Figure 4) - do this again to attain a rotation of 180°.
- You'll now have two pendulums with their weights in opposite
directions - drag the duplicated pendulum to that both the lines
join to form a single line as you can see in Figure 5.
- Select the top pendulum and click the arrow next to the Line
Color icon in the Drawing toolbar to open a fly-out menu - choose
the More Line Colors option in the menu to summon the Colors
dialog box that you can see in Figure 6. Drag the transparency
slider in the dialog box until 99%. Click OK to get back to the
- Make sure that both the pendulums are selected
(two lines and two circles) - and group them by right-clicking
and choosing Grouping |Group in the right-click menu. Since the
second pendulum is now essentially 99% transparent, you'll only
be able to see a very faint representation of that element on
- With the group selected, choose Slide Show | Custom Animation
to activate the Custom Animation task pane. In the task pane,
choose Add Effect | Empahsis | Spin. If the Spin option is not
available, choose Add Effect | Emphasis | More Effects | Basic
- Now select the animation in the animation list - and click
the downward pointing arrow next to the listing to reveal a fly-out
menu as shown in Figure 7.
- Select Effect Option to bring
up the tabbed dialog box shown in Figure 8.
In the Effect tab, place a check mark next to Smooth start, Smooth
end, and Auto-reverse options.
- In the Amount dropdown box, choose the Custom option and type
45° - also choose the Counterclockwise option. (see Figure
- In the Timing tab (see Figure 10), change Start to With
Previous, make sure Speed is set
to Medium, and Repeat is
set to Until End of Slide.
Click OK to get back to the slide.
- You can now scale the pendulum size to become larger, even
if the top area of the pendulum (that is 99% transparent) goes
above the slide area.
- Preview and save your presentation.