Domino and Compound Angle Moldings

[jturner421]

A molding for one of my kitchen cabinets recently came off that was never properly put together. I'm looking to use 5X30 Dominos to reassemble it. I'm having a hard time figuring out how to cut the corresponding mortise on the opposing piece.

The angle once together looks like this:

There is not a lot of surface space to line up the Dominp

I'm not clear after cutting the first mortise how to retain the angle for the corresponding piece.  Any suggestions would be greatly appreciated.

 

[nclemmons]

I'd suggest you hold the piece with clamps or in a vise.  You can index off of both back-side faces with your lines drawn accurately across the two faces on both pieces. 

1 - The fact that both MORTISE plunge faces are on the SAME plane makes it easier.

2 - Open the Domino fence to 90 degrees and tighten it down.

3 - Mark your reference marks with a square across the two faces on both angles.  Square the marks to the backside edge.

4 - Place the domino with the 90 degree fence registered to the back-side of the moulding.  You want the Domino to fit flush to the interior of the angle, so the fence will not fully contact the back side since it is a greater than 90 degree angle.

5 - Plunge and then rotate the Domino 90 degrees and do the same on the other face of the same piece.

6 - Repeat on the other piece following the same procedure.

7 - The 'L' shape should give you registration to keep the domino flush when plunging and in alignment.

8 - The key thing is that the Domino references off the flat.  The mortise will ALWAYS be perpendicular to the face on both sides.  So you should be able to plunge into both sides and keep everything in alignment.

9 - The fence is your reference for spacing the Domino in from the back-side of the moulding.  You may need to increase or decrease to get your Domino in the right position from the back side.

Hope this helps.  Angles always make you scratch your head until you realize you want to plunge perpendicular to the face for all dominos.

neil

 

[Gregor]

The idea behind the domino is that you register it on the same edge of a seam, on both workpieces.
For this to work the approach is to put both the registration plane (where the drill comes out) and the fence firm against the two sides (that are at that edge) of the workpiece, which will perfectly align the domino in a repeatable way that results in a mortice perpendicular (to the face it's created in) offset by what you set on the fence (height) of the domino.

The problem is when you have to register on an edge that is sharper (as in your problem, as you can't use the inner side of the workpiece because the fence is so wide that it won't fit) and you need to reference from the other side to have a flat face for the fence to register.

You can work around sharper edges by clamping a helper block flush with the outer edge, resulting in a duller edge you can reference the domino against:
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