You just need a mandrel with a 1/4 ir 3/8" shaft on it. Any of the
handpieces loke Foredom have the mandrels as well as the 1/(" Dremel
mandrels.
Tool shops should have all the mandrels that you'd desire.
I'll note that a drill motor doesn't have enough rigiditity in the
pistioning of the chuck in and out of the motor to really handle a slitting
saw. You'll have all kinds of problems ussing something like this. Much
better would be to make up a sort of table saw with a groove in it so that
the winding mandrel with the rings on it can slide along nicely against the
blade.

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Why isn't there an Ozone Hole at the NORTH Pole?