Mini Garden Zip Line STEM Challenge

I think our garden zip line using teddies is one of my favourite activities we’ve ever done, just because it’s so adaptable to children of all ages and abilities. My 4-year-old uses it as a big imaginative game, talking to her teddies, telling them not to be scared and lining them up so everyone gets a go. My 6-year-old makes the most amazing harnesses for us to test, and my 7-year-old likes to time the descent and find the fastest combination of zip line, harness and incline of the wire. I cannot tell you how much it made me smile to watch the three of them busily working away on their different approaches to the activity.

The zip line is brilliant outside on a fine day and also a great indoor boredom buster. You could even set up several zip lines in a row and race!

Garden Zip Line

What you need to make a teddy zip line

Teddies or small play figures

String, wire or wool

Pipe cleaners and straws

Timer

How to make a teddy zip line

This is a great activity for learning about correct experimental methods.

Start by listing the potential variables. Have we forgotten any?

Experiment Variables

Type of zip wire

The incline of the zip wire

Weight of teddy

Type of harness

To test one variable, all other variables must remain constant. For example, to test whether the weight of the teddy makes a difference, the type of wire, incline and harness must stay exactly the same. It’s good practice to repeat each test 3 times and calculate the average time taken to help reduce errors.

Test each variable by recording the time taken for a bear to travel from top to bottom.

Try to work out the best combination of each variable to get the teddy to the bottom of the zip wire fastest.

Things to think about – garden zip line

Friction

We found the descent was much slower with our rough string than with smooth wire. This is because the string is rough, meaning there is more friction to slow the bear down. In the same way, our harness with just the pipe cleaner made for a slower descent than the pipe cleaner and straw. The straw is much smoother, and so reduces the friction, speeding the bear up.

Please be very careful with this activity, it’s for teddies and small soft toys only!! Supervise children at all times.

More Friction Experiments

Simple slipping and sliding activity.

Try one of our fun forces and motion experiments.

A rocket zip line is another fun friction experiment idea and can be found with 69 more space-themed science experiments in This Is Rocket Science.

Last Updated on July 9, 2025 by Emma Vanstone