Festool Domino DF 500 - Manual (Page 18)

18 Domino DF 500 Tenon Joiner
Making Three-Way Lock Miter Joints
Three-way miter joints (also called a parson’s joint) have
been around for ages as a way of creating a corner joint
without having any endgrain visible. Using the Domino
Tenon Joiner, you can create easy to construct, locking,
parson’s joints.
The key to these joints is that they require floating tenons at
45 degrees to the main body of the wood. Unlike non-locking
joints, no single piece can be removed from the joint without
separating all three pieces. The joint must be assembled or
disassembled all at once.
The first step in creating the joint is creating the frame
stock. Each piece of the frame must be square in profile. In
this example, the frame stock is 2 inches by 2 inches.
Smaller stock can be used, but you may have to trim the
corners of the tenons where they intersect (the transparent
image in the middle-right shows the Domino tenons just
barely touching).
The square frame stock then needs to be mitered. Each
piece is mitered at 45 degrees from two different faces,
creating a pointed, double miter.
With the frame stock cut and mitered, set up the Domino
joiner. The following settings are based on using 8x40mm
tenons in 2-inch by 2-inch frame stock:
1.
Set the fence height between 8mm and 10mm.
2.
Set the plunge depth to 20mm.
3.
Set the mortise width to the minimum setting.
4.
Using a sharp pencil, mark each mortise location at
45mm (1¾ inch) from the point of the miter (see image
below).
5.
Plunge a mortise slot at the pencil line of each piece.
6.
Assemble all three frame members simultaneously.