I think I would start by cutting strips of the MDF 3 3/8 wide X 48 long.
Next, I would draw a center line down the middle of the strip and walk of
center points with a set of dividers every 3.4 inches.
Set up your drill press with a fence and drill your blanks with the circle
cutter others have mentioned.
One thing others have not suggested is using a router bit with a bearing on
it to control the depth of the cut. This is a whole lot easier than rigging
The slot can also be done on the lathe, easiest would be a metal lathe with
a mandrel set up, but the router would be the quickest way.
Last step would be to enlarge the 1/4" hole to 3/8". To do this I would
make a jig by screwing a piece of 1/4" or 3/8" to a sheet of 1/2" or 3/4"
and adjust your circle cutter so that the hole you make has an inside
diameter of 3 1/4 so your parts fit snug. With this clamped on your drill
press you should be able to drill out the pilot hole to size with no
I would recommend either a forstner bit or a brad point bit and to prevent
tearout, you might want to punch it half way and flip the disk over.
What are you using all of these disks for anyway?
About the time I had mastered getting the toothpaste back in the tube, then
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