|
|
|
|
Set the combination square to 4" and check mortise depth. Tenons are cut to 3 3/4" so a 4" mortise assures clearance. |
. |
|
|
|
|
Check mortise width using a framing square. The framing square has 2" blade and 1 1/2" wide tongue. The framing square should move freely in the mortise. If the framing square blade it is snug, the mortise is too tight. Timber framing joinery should fall together. |
Check mortise length. |
|
|
|
|
The over drawn lay out line indicates the point where the 45 deg back slope would meet the bottom of the mortise. This is a helpful visual marker when cutting the joint. |
Check the mortise back face for 45 deg. |
The combination square blade should touch the face at the surface of the timber. Enough wood is removed from the back face so the brace tenon will have clearance. If excess wood is removed it is okay.
Check the mortise front face for square. The combination square blade should touch the face at the surface of the timber. The front face is the most important surface of this mortise. The other faces of the mortise (sides and back) are just for clearance for the brace tenon. However, the brace / timber forces are transmitted through the brace mortise front face. Also, the distance from brace mortise front face to brace mortise front face is very important to make a square frame.
workshops / timber frames / gazebos / outbuildings / playhouses / apprenticeships