Project: "Making a Big Wall Clock"

My wife and I visited some old friends of hers and as we entered their house, I couldn't help but notice a great clock. It was 20 inches in diameter so it would have been hard  to miss. I thought it was just an "art" piece, but as the hands turned, I saw that it was a real battery operated giant clock — and I had to make one.  I took a couple of measurements.
	I think making a copy is doable, but I either had to make a detailed paper copy or just get to the shop and start dummy-ing it up.    I am using a 24" X 48" piece of MDF. The original is MDF painted black. The outside diameter is 20", but I am going to cut the first circle at 22" diameter so that I have room outside the actual clock to screw down templates. I start by drilling a 1/8" hole to hold the center pin.
I have mounted this circle jig (click here for information) to the plunge base of my new PorterCable 890 series router. I have inserted the pin at the 22" position (arrow).
	I am installing a 1/4" diameter up-spiral bit.  I expect that this bit plus the vacuum attachment will give me good clean cuts. By the way, this circle jig  dimensions are based on using a 1/4" cutter. If used with a larger diameter bit, you adjust the dimension accordingly.
I have plunged the router so that the bit just touches the surface. That is "zeroing" the router depth. Then I raise the plunge stop and set it to the 3/4" thickness of the MDF — and then I add a "skosh" to route a clean break all the way through. Note that I have placed the workpiece on a piece of 1" Styrofoam insulation board. I can route into this without any problems.
	With the vacuum hose connected to the router base's port and the router, itself, plugged into the vacuum, when I route, the dust and chips should be drawn out of the groove — "should be" being the key words.
With the router plunged abut 2/3 of the depth, it is like cutting butter. The up-spiral bit cuts cleanly without any resistance. Furthermore, the cut is clean and the groove is dust-free. The vacuum setup with this base is perfect. Without this hook up, the groove would have had to be cleaned after each pass.
	Now I have a very clean cut 22" diameter circle.
I took this picture to show you the foam insulation board that I have under the MDF. Cutting into this board does not create a problem. It is a good way to keep the MDF off table tops that could be ruined.