How to Build a Cedar Log Swing. A cedar log swing can add a unique look to your backyard and provide many hours of enjoyment. If you have some carpentry skills, you can build your own cedar log swing in a day or less.
Cut 45-degree angles at both ends of the four 97-inch logs. The angles on each log should run in opposite directions. Lay two of the 97-inch cedar logs on the ground in a V-shape, arranging them so that the ends are exactly 72 inches apart. Do the same with the other two logs.
Drill two pilot holes into the tops of the 97-inch logs at the point where the angles meet at the top of the V. (One hole should be about 2 inches above the other.) Use two large bolts, at least 8 inches long, to attach the logs together at the top. Affix a washer and nut to the end of the bolt and tighten with a ratchet or wrench. Attach the other set of logs together in the same fashion.
Chisel both ends of the 84-inch log to create a wedge shape that fits snugly into the angles formed by the tops of the A-frame.
Drill a hole from the top of the 84-inch log to the bottom. The hole should be 8 inches from either end of the center post. You will use these holes to suspend the chair.
Insert the hooks into the holes you just drilled out so that they extend from the bottom of the log. Use two washers per hook, then use the nut to secure the hook bolts into place with the hook openings facing forward. The hooks and eye bolts will provide the swinging point for the cedar swing.
Drill two angled pilot holes in the near the ends of the 84-inch log so each hole points to one of the legs in the V you have created. Set up the legs and screw the 84-inch log onto the top of the 97-inch logs with heavy duty bolts at least 6 inches long, securing the ends with a nut and washer.
Cut two 48-inch lengths from the 3-inch-diameter cedar log to use as cross supports for the A-frame. Use 6-inch bolts to attach the cross supports to both legs on each side of the frame so that the cross supports are parallel to the ground.
Add additional support to the swing by attaching four diagonal braces at the top of the A-frame that run from the center beam to each leg on the front and back. The braces should attach at 45-degree angles and connect 24 inches down the sides and across the top of the frame. Use the 3-inch logs.
Build the chair for the swing by building two 66-inch long rectangular frames with the 3-inch logs. One of the rectangles should be 66 inches by 2 feet (this will be the seat), while the other should be 66 inches by 3 feet (this will be the back rest). Add a horizontal brace in the center of each rectangle. Measure and cut the 1-by-4 boards to match the short measurements on the rectangles. Lay the 1-by-4-inch slats across the rectangles in a vertical direction, attaching them at the top, bottom and center with small wood screws or finishing nails.
Sand the boards of the swing with medium (about 120-grit) sandpaper until they are smooth to the touch.
Use two 3-inch logs to run from the bottom of the chair to the eye hooks in the center beam. Screw the eye bolts into the top of the logs, at the very center, with the help of a large screwdriver. Attach the logs to either side of the base of the chair, about 10 inches from its front. You can choose the length of these logs to match the height for your swing so your feet touch the ground when you sit on the seat.
Build a support brace that runs from both sides of the chair's back side up to the log with the eye bolt. Use the 3-inch log and cut an angle into the end of the log as needed. Attach with 4 1/2 to 5-inch wood screws.
Hang the chair on the swing by placing the eye screws onto the hook bolts.
Cover nail heads and screws with the wood putty.