Interested in making your own swing you can carry along to festivals or to the park on sunny days?
Than this instructable is perfect for you!

Step 1: Step 1: Materials

A piece of linoleum (or something similar) that's at least 80cm long and 20cm wide
Some synthetic rope (about 20 meters should do it) with a diameter of 8mm
A pine beam (I used one that's 50cm long and 4cm thick)
18 eyelets (10mm)
Eyelet puncher
A hammer
A utility knife
A skateboard deck
A drill
A pencil

Step 2: Step 2: Making the Seat

Place the skateboard on the linoleum and draw the around the edges. (image 1-3)
This should be around 78cm long and 19cm wide. (image 4-5)
Cut out the shape with a utility knife or use a shear machine for the rough edges and finish with a utility knife (image 6-8)
Drill 9 holes at each side with a 10mm drill. These holes should be at 4.5cm from the side at one side and 9.5cm from the other (this is measured from the furthest point of the arc). The space between each hole is 7.5cm. (image 9-12)
Use the eyelet puncher and a hammer to get the eyelets in place (image 12-13)
You should have something similar to this (image 14)

Step 3: Step 3: Making the Suspension System

Cut the beam in half (image1-3)
Mark 2 points on each half (image 4)
On one side at 3cm from the edge. The next one is on the same side at 11 cm (image 5-6)
Do the same with the other half
Turn the beams 90 degrees and find the middle of the 2 points you've drawn earlier, this is your third point
The fourth point is at 11cm from this point
Drill these points with a 10mm drill
It should look like this (image 7)

Step 4: Step 4: the Rope

Cut the total amount of rope you need (see below) in half

The length of rope you use is important. If you want to know how much rope you need you need to know how high the tree branch is.

Example:

The tree branch is at a height of 4 meters and you want your swing to be 50 centimeters from the ground.
4 - 0.5 = 3.5
you'll need this length 4 times + the rope that goes through the suspension (about 60 cm) + the rope that goes through the seat (about 160 cm)

That makes a total of 16.2m

With this you calculate with a maximum height, you can always go lower ;)

Step 5: Step 5: Preparing the Swing

weave the rope through the seat (the middle hole isn't used)
start at the bottom and go up
do the same on the other side
take the rope on one end and put it through the 2 lowest holes of the beam
do the same on the other side

Step 6: Step 6: Swinging

How to get the swing in the tree:

stand on one side of the tree and throw the beam over the tree
use the rope from the same side of the seat but on the other half and put these through the other 2 holes of the beam to put the seat in place. You can also adjust the height of the seat by pulling more rope through the beam.
stand on the other side of the tree and throw the other beam
do the same to put the seat in place