Nothing announces the start of summer quite like children playing on a swing set. A wooden swing set built from scratch is an enduring expression of parental love as well as one of the few recreational play sets that can increase your home's resale value. Since safety is so important, some people may be tempted to overengineer the design of a swing set. However, a basic A-frame design is quite safe.
Dig four postholes that set off a rectangular plot at least 2.4 m (8 feet) long and 1.2 m (4 feet) wide. Each posthole should be 60 cm (2 feet) deep. To prevent the swing set's top rail from sagging, do not allow more than 3 m (10 feet) between postholes on the long sides of the plot.
Construct the two A-frame end sections by attaching two 10 by 10 cm (4 by 4 inch) posts to each A-frame bracket or A-bar swing set bracket. Adjust the brackets to an angle such that the bottom ends of the posts of each A-frame can be set into the pairs of postholes along the 1.2 m (4 foot) sides of the plot. Because of the size of the A-frames, it may be easiest to assemble them close to the postholes where you will be positioning them.
Before connecting the top 10 by 15 cm (4 by 6 inch) rail to the two A-frames, drill holes in it for each swing or other swing toy that will be suspended from it. Allow enough space for each swing or other suspended toy to be used safely.
Use either long nails, heavy screws, or bolts to connect the top rail to the two A-frames. For a secure fit, cut notches into the tops of each A frame that will fit the 10 by 15 cm (4 by 6 inch) rail. If needed, add diagonal corner bracing to support the top rail. Once the top rail is securely connected to the A-frames, cut off unneeded sections of the rail that extend beyond either A-frame.
Position the swing set frame by placing the bottoms of the posts of each A-frame into the postholes along the 4-foot sides of the plot. Do not secure the A-frames with cement yet, since you still may need to adjust the posts slightly after adding support brackets to each A-frame.
Cut the remaining 10 by 10 cm (4 by 4 inch) posts into pieces that will serve as braces for each A-frame. Nail or screw at least two braces between the posts of each A-frame. Add enough braces to prevent wobbling. Trim away any excess wood and smooth out sharp edges along the A-frames, since children tend to be attracted to sharp edges, often with unfortunate results.
Mix the cement following the manufacturer's instructions. Pour it into the postholes around the bottoms of each A-frame post. Use enough cement to secure the bottoms of the posts. Let the cement set and dry for at least one day.
Test the frame again to make sure it doesn't wobble. If it does, repeat Step 6, adding enough cement to secure each A-frame entirely.
Attach the hardware for swings or other swing toys to the top rail, after the swing set has been securely positioned and the cement has entirely dried. For each swing, you'll need two eyebolts, 3.6 m (12 feet) of 1.2 cm (1/2 inch) chain, and a swing seat.
It is easier to paint or stain your wood before beginning construction. A wood stain is not only attractive but also protects the wood from the elements. Consider looking online for swing set construction kits that include precut hardware, brackets, braces, swing seats, and other swing toys.