You will need
- 21 ropes for lashings and guys
- 4 stakes to anchor project
- 1 round spar for roller
- 4 longer spars for A-frames
- 2 spars for A-frame bases
- 5 small spars for connectors
- 1 sturdy plank as see saw seat
- 2 tires to cushion landing
Before you begin
- Before building your seesaw, check that your ropes and spars are in good condition and not likely to break whilst it is in use.
- Try to scale the project with those building it. Nothing should be too heavy for one person to lift and use safely.
- Make sure everyone has sturdy shoes on and that the ground you’re building your seesaw on is steady, level and presents no other hazards.
- The design of this project is simple, but it needs tight and precise lashings. Everyone will need to work together to make sure everything’s level and to keep checking that the balance of the seesaw is correct.
- Use the attached assembly instructions for a visual explanation of the project.
Ready set seesaw
- Start making two A-frames. Take two similar-length spars and tie a sheer lashingon one end. This will be the top of one frame.
- Pull the two spars apart at the other end. Lash a third spar across the base of the ‘A’ to make the support. Use a diagonal or square lashing.
- Make a second A-frame in the same way and check that both are the same size and shape by standing them up, side by side
- Select a spar for your roller The width of this spar is how far apart your A-frames will be.
- Take the roller out once you have the size it needs to be as it will be difficult to make the lashings with the roller in place.
- Use a square lashing to fix the roller in position using four shorter spars and use a fifth to connect the tops of both A frames together.
- Lash the bottom ones first, this means that you can lay the roller in place on the bottom set to check the height again before fixing it in place.
- Hammer four stakes in the ground at 45-degree angle in a square around where the seesaw will stand. These will help to stop the seesaw tipping over so will need to be firm and the guy ropes securing them should be tied tightly. Using a round turn and two half hitches but with more half hitches is one good way to do this.
- Square lash a plank firmly to the centre of the roller. Make sure you have the same length of plank on both sides of the seesaw.
- Lay the two tyres beneath either end of the plank, to cushion the landing when either end comes down.
- Remember to explore the science behind seesaws too with the information in the dropdown below.
This activity demonstrated your pioneering prowess. While the design of the seesaw is simple, the knots and lashings needed to be placed precisely. This meant that you needed to slow down and think carefully before tying them. How many times did you check your lashings were correctly tied and tight enough to hold? Why might this be important, given what you’ve learned about levers and loads, and given the size of the seesaw you’ve built?
Planning ahead can be boring and get in the way of the fun, but taking your time to approach problems properly can mean a greater chance of success. How did everyone do their bit to help make the seesaw come together? This was a chance for everyone to demonstrate their strengths, whether those were knot-tying, instruction-following, project-managing or seesaw-testing.
- Outdoor activities
You must have permission to use the location. Always check the weather forecast and inform parents and carers of any change in venue.
- Poles and long objects
Be careful when moving poles or long items. Take care if the ends are sharp. Have appropriate supervision for this activity.
- Heavy and awkward objects
Don’t lift or move heavy or awkward items without help. Break them down into smaller parts if possible.