Tools and Materials
For this project you will need six pieces of 12-foot pressure-treated 4 x 4 lumber, one 12-foot pressure-treated 4 x 6 piece of lumber, concrete mix, metal swing set post brackets, circular saw, drill with screw bit, level, post hole digger, clamps and a socket set.
Measuring the Area
The first thing you should do is measure the area around where the swing set will go. The length of the swing set will depend on the size of the yard. Make sure you build it far enough away from obstacles so the swings have adequate clearance. Also, measure so that you have no more than 10 feet between your support columns so your top bar doesn't sag. The length of the swing set will depend on the size of the yard.
Building A Frames
Now you should build your support columns. The first thing you should do is make notches in the four pieces of 4 x 4. To do this, measure 6 inches on one side of the 4 x 4 and make a mark. Set the circular saw to 12 degrees and cut 2 inches into the wood at the mark you made. Then, with the saw at the 12 degree setting, cut from the top of the 4 x 4 until you reach your first cut. Repeat this on four of the pieces and clamp them together in pairs, forming an "A" shape.
The remaining 4 x 4 pieces will be used for braces on the A frame support columns. On one of your frames, measure two places where supports will go. Usually, there would be two supports, but you can put more if you feel more comfortable doing so. Transfer your measurements to the remaining 4 x 4 and cut the support beams (the saw will most likely stay with a 12 degree angle). Attach the support beams to the A frame.
Setting Up the Frame
Once you have your A frames complete, measure where they are going to go. Use the post hole digger and dig a hole for each post that is 18 inches deep. Mix the concrete with water so that it is the consistency of really wet mud. Place the A frames in the holes and cover them with concrete. Use the level to determine if the posts are straight or not. It is extremely important that they are so be sure to spend time moving them if necessary. Once all the posts have been set in concrete and are straight, let them dry for a few days. Once they are dry, attach the 4 x 6 to the top with screws and the metal brackets. Now that the frame is complete, you can purchase the playground equipment you want.