This K'NEX double swing looks like fun!
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It can be built using:
1. A K'NEX Base kit.
2.Two Fimbles (or two cuddly toys of similar size).
First, assemble the nine 3D connectors shown in the photo opposite.
Please visit Handy Hint A4 if you need help to do this.
Next, add to a grey rod, as shown:
1.Two blue spacers.
2. Four silver spacers.
3. Two purple clips.
4. Four more silver spacers.
5. Two more blue spacers.
Then add the same to a second grey rod