A while back someone had asked how I planned on finishing the top and back of the cabinet since there are no straight lines. After a number of years I'm finally able to explain the answer with some actual pictures. From a design standpoint its very important to me that the curves of the cabinet be a structural part of the cabinets shape, and not a facade seen only from the sides. The last thing I wanted was to have the cabinet end in flat panels on the back and top, so the top and back will have curved panels that follow the profile of the cabinet.
There are two curves along the top with a vent in between.. the second of these, at the rear of the cabinet wraps around from the top to the back and ends in an arched opening. An additional curve at the bottom rear of the cabinet extends upward from the floor ending in an opposing arc, so when seen from behind the cabinet has a circular opening that will be used as an access hatch for the monitor and insides.
To make these shapes I built forms much like the one used for the coin door/kick panel arch. To ensure that the resulting pieces would fit the spaces intended for them, I built the skeleton of the forms in place on the cabinet. The "wider at the top than the bottom" nature of the cabinet meant every few inches of each form was a different width. Combining that with the curved shapes would have been more math than I think I could ever learn, so making the forms a near "mould" of the space the panels sit in seemed to be the easiest and most accurate way to build and then trim them.
I printed out arches in the shapes of the curves I wanted to create then made MDF templates from the printouts and cut the arches out of poplar. I screwed them into position on the sides and then attached a couple of plywood panels between them horizontally with epoxy. Once removed the idea is that they create a form exactly the width and shape of the side panels, making it easy to trim the final curved panels to the exact width/shape of the space they occupy by using these forms as a cutting template with the router… (keeping in mind that the width of the cabinet changes from the top to the bottom I was really concerned about gapping and the panels not fitting flush.. they sit
between the side panels, not on top since that'll give it a much more finished look.)
I made a bunch of matching arches to build each of the forms.

For each form I screwed (not glued!) an arch on to each inner side of the cabinet. Then I epoxied plywood to the arches and once dry, unscrewed the arches from the sides. I had wax paper in place to avoid any problems with the epoxy squeezing out.

Here is the first form removed from the cabinet but maintaining the toenailed angle of the sides.

After removing the first form I found that, despite my best attempts to avoid it, epoxy had squeezed past the protective wax paper masking between the poplar curve and the cabinet side. As I panicked and hastily checked to ensure no epoxy had stained a visible part of the cabinet's side…imagine my surprise as I discovered the face of Nolan Bushnell staring back at me like so much Face-of-Mother-Theresa-in-a-Cinnamon-Bun.

If you don't believe me read the fine print in the article below. You'll need to ctl+click it to open it full size in a new window. The actual image is viewable much larger than what it defaults to below.
