As you can faintly see in the photo below, I marked each board with the lines for all of the pieces.
I used my radial saw to make all of the major 'board' cuts and although you can't see it (I didn't think to photograph the underside and the dust while cutting was too intense to bring the camera out), I mitered both edges at a 45degree angle so that each side would meet at the corners. Make sure you have a dust mask and goggles. These are key for all of the cutting and sanding. I sanded after every cut so that the edges were always nice and clean. I used my electric sander which made the process go quickly.
I used regular molding from the home improvement store for the straight pieces of molding. The ends have all been mitered to match the 45 degree of the board.
The round rosettes were purchased online, they are 2.5" diameter. I glued everything on with liquid nails and/or HWFF Foam glue. The foam glue is not as thick and dries slightly faster, which I ended up preferring.
I cut the square middle pieces from 1/2" pink foam and glued them on. One piece gets a round hole, three do not.
So up until this point I was motoring along and pleased with myself for all the progress. However the true test was coming...the curved top trim.
Originally I thought I could make this with my hot wire tool and I started with good result.
However when I started the curved piece it all fell apart. I couldn't get a jig together that would hold the tool at the right angle and curve it at the same time. I tried and tried (for way too many hours I tried, and thought, and ate some chocolate, and tried again). No, this was just not going to work. So while not exactly the right profile I came up with this.
I used 2 sizes of pipe insulation from the home improvement store. The ends are mitered at 45 degrees to match the sides of the board and the middles are at 35 degrees or so. I glued the ends on first and let them set up. Once firm and dry I added the curved middles. I was pleased with this and so went to the next step, adding small diameter window and door insulation in between the "steps" so that it would look more like real trim with the little peaks and valleys. The styles I used are below. The best part about these are that they come with adhesive built in. Just peel of the tape and you're ready to apply.
Next I cut craft foam sheets into 2" strips, mitered the outside edges to 45 degrees and glued them to the top of the pipe foam to create the "roof" of the trim
Then I added a large trim piece to the bottom and again mitered the ends. Now, for you observant folks, you will notice that some of the square pieces in the middle are solid, and others show a round recess. This is because the Poe stone has one side that has a bronze relief and the others do not. I didn't keep tabs on which piece was in front while I photographed.
This photo includes a really cute model to distract from the fact that I neglected to take photos of several stages.
One: I glued the four board components together and let them dry. I think you can figure how how that works so that's not a big deal. I used blue painters tape to hold them in place. This works well on the foam provided you stick it down really well and it's not too humid.
Two: I made simple rectangular boards and mounted them to the bottom. Again, fairly straightforward.
Three: I made the pyramid top and glued it on. Sounds so easy, right? NOT. Although it was fun to use my geometry skills for once in 20 years.
To figure out the dimensions of the four triangle shaped sides I first decided that the pyramid should be 6" high.
So for the first formula, you have to imagine a cross section of the pyramid. Take a straight line from the tippy top of the pyramid down to an imaginary table it is sitting on. Then continue that line to the middle of one of the sides. If you continue the line up the sloped side back to the top, you've created a right triangle. The height of the right triangle is 6", and the base is 12" (each side is 24", so half of that, to the middle, is 12"). From there you use your formula to get the hypotenuse of the triangle. a2 + b2 = c2 (those 2s are supposed to read as "squared"). Thus you get 6 squared (36) + 12 squared (144) = 180 whose square root is 13.41. So when you go to cut your triangle pieces, they should be 13.41" tall, and 24" wide at the base. I just drew them out and connected the dots to complete the triangle. Although you could again use your formula if you love it so!!
I cut the four triangles out of 1/2" foam and then mitered all three edges of each triangle so that they would match up flush when glued together. Now in reality they weren't exact, (well, at least my reality. Maybe you're a better carpenter- it wouldn't be hard) but I evened everything out in the end with some sanding and joint compound.
So that was a lot. Are you still with me? Only one more post to go...