Things are shaping up nicely! I have the top nearly finished as of this writing. I'll begin taking you through the steps up to this point. I'm going to do this in small, digestible chunks for those of you who are not woodworkers. For the sawdust lovers who are reading this, please be patient... I'll get to the details you want soon enough.
Here is the material I'm using for my top. It's 1/8" melamine coated hardboard laminated to regular 1/8" hardboard. The opening for the router plate has been rough cut (VERY rough cut... I hate my jigsaw), and two points have been located and drilled out so that it can be mounted to the jig I used to rout out the opening to it's finished dimensions. The same points will be used to mount it to the substrate of the router table itself when the time comes.
Here you can see the finished jig. The two points I have circled with pencil line up with the two drilled points on the melamine top. When screwed down the top lines up perfectly with the jig so that the opening I cut matches the opening I have already drawn onto the top. The melamine surface mounted in the center of the jig serves only to to keep the router base level so the sides of the opening will be at right angles to the top. It also makes the job a lot easier because there is no chance of the router suddenly tipping to the side during a lapse of concentration on my part.
Here is the top screwed onto the jig, ready for routing. You can see the size of the whole thing as compared to my small level, which is one foot long.
And here is the router with a bearing guided bit chucked in it. The bearing rides on the inside edge of the jig I built while the cutters slice off the melamine. The bearing and the jig keep the cutters from removing too much material and the result is an opening that is perfectly sized to fit my router plate.
Next time: I'll actually turn on the router and get to the fun part!