In this insturctable I am gone explain to you how to build a dog swing in 4 steps
( special tanks to my dad , he made this swing)

Supplies

Materials are
7x 75 cm of 50mm pvc tube (total of 5.25m of tube) take 2 short pieces to connect the bends to the y pieces this is not included in the total length
6 90°bends
2 y pieces
6 eye screws
2 chains of 140cm in length
And a board of 70 x 42 cm
Tools
A hack/pvc saw
Pvc glue
A wood saw if the board is not the right size
Plaiers in case you need to open the eye screws

Step 1: Sizes

Take al your parts and cut everything to size
Pvc pipe to 75 cm
Chain to 140cm
And the board to 70 x 42 cm and sand over the sharp corners

Step 2: The Frame

Take 4 of your bends and 4 of your pipes and make 2 U shapes (see picture 1).
Now connect the y parts to your U shapes (see picture 2) you should now have a triangle structure .
Now connect 2 remaining bends to your remaining pipe(see picture 3) and with 2 short pieces connect in as is in picture 2 .
Now take a dril an dril 2 holes around 3 cm form the bends as shown in picture 3 an screw in 2 of your 6 eyes
The frame is now done.

Step 3: The Swing

Take your board a dril 4 holes in the corners.
And screw in the eyes. Like picture 4
Now connect the ends of the chain to eyes along the short side of the board do the same thing on the other side .
Now you only have to hang your swing so it's level with the ground
Now it's done you can customize it how even you like.