This was my 1st 'large' project on the B9, the acrylic radar assembly.
Using the normal procedures found on the net for this it was pretty much a follow the blueprints. But, I did make one change, I added two 1/4" smaller disks to the inside of the top and bottom piece of the large disks. This was so I had something to glue the outer curved piece to. For that, I heated the 1 inch wide strip in the kitchen oven (when the wife was out, timing is everything to a happy marriage) and then used the inner 'race' of the smaller disks as a bending, glueing guide while it was still warm. Worked out pretty well.... The burned fingers were not too happy about it, but it came out great.
For cutting the circles, a rotozip is the only way to go !! For three reasons, its fast, its easy, and gives you a great excuse to buy a new tool !!
I worked on this about 1hr a night for two weeks (I had to redo the top part once, I didn't like the way it came out) plus a couple of hours on one Saturday. Then I didn't like the L pieces I cut and redid them three times.... I'd estimate the time of 30hrs.
$40 in acrylic and then some glue.