OK guys I don't draw on a computer anyway and I'm using this picture to make the plans so here we go. Lets start with cutting the parts for the top and bench seats. It's up to you what material you want to use. There are a number of different woods you can use, the most common would be redwood, cedar or pressure treated pine. To make the material for the top come out symmetrical I planed it with using 10 2x6 boards for a diameter of 55". What I have drawn is simplified and you could save lumber by shortening some of the pieces that would go to waste but that is your choice. Lumber also varies in size so you may have to alter my dimensions. Lay out 16 straight 2x6 boards 56" long face down on the floor or if you have a large enough bench. Then mark the center. You may have to tack a thin piece of plywood there because the center may be on a seam. Then make a protractor like I have illustrated and set the nail 27 1/2" from the pencil notch. Now from the center mark you can draw a 55" circle which would be the top. Now move the nail out to 31 1/2" and draw the inside line of the benches. Then move the nail out to 44" and draw the outside edge of the bench. Now the dotted line is the center of the walk space between the benches. If you mark a line 8" from that line this will give you 16" between the benches. If you want a different space you can cut it smaller or bigger however it appears there is not a great deal of seating space between the leg and the end of the bench so I wouldn't make the space much bigger. After you've got everything laid out to suite you, you can cut the radius with a saber saw or band saw and sand the edges after it is assembled. If you use a saber saw you might want to cut outside the line. I've never had a saber saw that would cut 90 degrees all the time. You could also screw some 1x4's across the back side and use a circle cut router if you have one. Now with what you have there, there is only two benches. Once you've cut out one of the benches out you can use it as a pattern to make the other two which are not shown on the drawing.
The next drawing is the cross members to assemble the top and have a place to attach the legs. Use the longer 2x4 perpendicular across the joints of the top to tie them together and then run the shorter ones with the grain. Then if you plan to make a hole for an umbrella don't put any fasteners directly in the center. You will need some additional blocking on the ends but that could just be some 1x4's.
For now just wait on assembling the bench tops. Let me know if I missed anything. I'll work on the next step.
Last edited by Steve Neul; 04-05-2012 at 02:46 PM.