The easiest way to draw a perfect circle is by using a hacksaw blade as a guide. Nail one end of a hacksaw blade into the centre of the formply, making sure that the other end is close to the edge. Put a marker in the opposite hole of the blade, then spin it around 360° to mark out your circle.
Clamp the formply securely to a bench. Put on your safety glasses, dust mask and ear muffs. Then use the jigsaw to cut out the circle for the back of the floating hoop shelf. Sand the edges to make them smooth.
Use the tape measure and a marker to measure the length of the horizontal shelf and the vertical dividers. The shelf will be the length of the diameter of the circular base, which in our case is 600mm. Make the dividers half that length, minus the width of the ply. In our case the top divider is 287mm from the horizontal to the frame edge and the bottom divider is 273mm. Once you have measured the horizontal shelf and supports, put on your safety equipment and use the jigsaw or drop saw to cut them out.
Measure the ply for the outer frame of your shelf. Both pieces should be half the length of the radius of the back circle, but add a little bit more so that they overlap and can be joined together. Wearing your safety equipment, jigsaw the ply to size.
Place the shelf in the centre of the circular base, so that the ends are flush with the edges. Bend one piece of the flexible ply around the base from one end of the shelf to the other. Pre-drill holes in the flexible ply and the ends of the long shelf. Use the drill and the black dress-screws to secure the ply in place.
Pre-drill holes into the circular base plate for the supports. Put the supports in place. Screw the supports to the base plate and the flexible ply.
Working your way around the shelf, drill the black dress-screws to secure the flexible ply to the shelf, the supports and the base plate. Pre-drill the holes first to stop the screws from burring.
To make sure the shelf and supports are secure, turn the shelf over so that the base plate is facing upwards. Pre-drill holes into the shelf and the supports through the base plate. Screw the shelf and supports to the base plate.