This is my take on the many choices out their for building a hexagon swing with a fire pit in the middle. Most have raised fire pits so I decided to try it with a sunken pit instead.
Step 1: Start
I started by using 6x6x10s. I created the Hexagon with scrap 2x6x8. I cut the 30 degree angle on each side to create the hexagon. Final board length was 95 inches. To create the concrete forms I again just used scrap 2x6 to create a larger hexagon. You can see my horizontal boards running across the bottom lining up the corners of both the 6x6 hexagon and the concrete forms hexagon.
I wanted my fire pit to be sunken instead of raised like I have seen so many others. Again using scrap 2x6 I created the centerpiece. Each of the 6 boards were cut to 25 inches in length with 30 degree angles on each end. I also now removed each top 2x6 one at a time and replaced them with the final 6x6 top piece. Again 30 degree saw cuts on a 12 inch sliding saw. I used 10 inch long timberlok screws down through the uprights and through the hex angles.
Here I added a series of 2x6 hexagons each one rotated to point to the centerline of the next. I also added 6x6 45degree angle bracing cut to 24 inches. This gave the swing stability. At this point everything feels solid. Since the fire pit is sunken I used 4 inch pvc with a cast iron top to drain off any water. I dug a small trench to set the pipe in and then used 2x10 to build the final fire pit form.
View looking up.
A view from the back deck. I used a bit of brown release and did more of a slate finish along the inside of the hexagon and kept a stone finish to border it all in.
I found a heavy duty hexagonal 36" grate online. I have had this set up for 2 yrs now and all the water drains off with no issues
This view show the concrete after the sealer was added. It really brings out all the colors and gives it the finished look.