Monday, January 28, 2008

Frame dadoes

3-wing slot-cutter. The bearing makes the resulting cut 9/16" deep, 1/4" is needed. The slot-cutter is bigger than the hole in the table so it's inserted from above, then the collet is tightened under the table - a royal pain.

Without a properly-sized bearing, another crazy jig is required to limit the stock getting any closer to the cutter than 1/4". Since curves will be cut, a radius needs sit over the cutter, and clearance allowed so the stock can be manipulated without wedging against the fence.

The bit shank length won't reach the whole cut (indexing from one side), so it's set up to take the required 3/8" of width in two passes, one on each side. This automatically centers the dado, but doesn't forgive ANY variation in stock width or feed pressure. The stock has already been flipped, the cutter is finishing the second pass, completing the dado in one of the center stiles.

In mid-cut on the curved top rail, it's obvious that burying the slot cutter in the fence wouldn't work.

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