Domino: How to mortise at the end of a narrow, mitered rail?

[CNX]

Hi all,

I need to mortise at the end of narrow rails of a high chair, little over 3/4 x 1 x 8 inches. I could use the narrow frame fence, but the problem is the end of the rail is mitered by few degrees. I wonder how you stabilize such narrow and mitered stocks for Domino.

I'm thinking about cutting MDF with the same miter angle, while my miter saw is still in the same miter position and use them as spacers (or wedge) for the narrow frame fence or somehow clamp down on the MFT.

I would greatly appreciate your advise here.

Thanks

 

[Healeyjet]

Can you do the mortise before you cut the angle on the end then maybe just trim the domino a bit shorter.
Ward

 

[ear3]

Can you do the mortise before you cut the angle on the end then maybe just trim the domino a bit shorter.
Ward

And use a deeper plunge depth

 

[Stone Message]

The motice needs to be at right angles to the cut line.

Peter

 

[CNX]

Well, the mortise-before-miter won't be a good idea, I believe and this is why.
If you cur a mortise before I miter the edge, the mortise is parallel to the long axis of the rail, but then the tenon would be angled with respect to the mitered surface. If this is the case, I believe I need to bore am angled mortise to the chair leg, which seems even more difficult.

I think it is always easiest to mortise perpendicular to the butted surfaces by Domino regardless of mitered or not.

Does it make sense?

 

[CNX]

I guess I double-posted with Peter, If I understood Peter's post correctly.

 

[Healeyjet]

I guess when he said " mitred by a few degrees" it wouldn't be a big deal if you used the wider slot on the leg end.  I understand what you mean Peter.
My bad.
Ward

 

[MahalaHomecraft]

I think the best thing to do would be to cut 2 pieces of material the same thickness as the piece you'e trying to mortise, at the same angle.  Then you can lay all three pieces on your workbench with the cut edges lining up, clamp them together, and the 2 pieces on the sides will keep your face sitting flat.

 

[Carl Prentiss]

The motice needs to be at right angles to the cut line.

Peter

I can think of a few scenarios where this may not be true depending upon which way the domino is oriented. The below illustration would have the fence set at 45* for both pieces and may be equal or complementary angles. Apologies for dragging this somewhat off topic as it doesn't apply to what the OP was looking for:

 

[wrightwoodwork]

Rubbish , you could do it like that I suppose I certainly wouldn't. Two reasons makes it harder than needs to be going at tight angles to the cut line as Peter says I personally think is far easier. The second reason is thier is an area above the tenons that had the potential to snap off as it looks maybe on 3or 4 mm.

 

[Stoli]

I made a couple of jigs when I had to do something possibly similar.

Here is a crappy video I put together for last year's contest.  Ended up not submitting since it was really just photos stitched together:

Here are the actual pics:

 

[RDMuller]

Since you are using 3/4 inch stock, you have an alternative option that is great.  Built a jig on a piece of MDF or plywood to hold the piece to be mitered in place at the correct angle.  Then, do not use the slip down fence on the Domino to set height.  Rather, use base of the Domino as the center of the bit is 10 mm above the base.  See this video for taking advantage of this on both Dominos and biscuit joiners.    You can do this on thinner or thicker pieces by shimming either the work or the tool.
Roger Muller Video on Domino and Biscuit Joiner Depth

You can find several Festool videos out there at my Festool channel.  Just google  Roger Muller Youtube channel festool

 

[Carl Prentiss]

Rubbish , you could do it like that I suppose I certainly wouldn't. Two reasons makes it harder than needs to be going at tight angles to the cut line as Peter says I personally think is far easier. The second reason is thier is an area above the tenons that had the potential to snap off as it looks maybe on 3or 4 mm.

Sorry you found my example rubbish. I'm just not ready to concede that a domino has to be at right angles to the cut line. Is this one any better?

 

[wrightwoodwork]

???

Rubbish , you could do it like that I suppose I certainly wouldn't. Two reasons makes it harder than needs to be going at tight angles to the cut line as Peter says I personally think is far easier. The second reason is thier is an area above the tenons that had the potential to snap off as it looks maybe on 3or 4 mm.

I can see that working better and not having the same risk of break out. As it don't appear to have the same risk of breakout from the pics I can see then a block to get the angle to rest the domino on to get the cutting. To me there is no point in complicating a job just for the sake of it. sometimes the simple way is the right
Sorry you found my example rubbish. I'm just not ready to concede that a domino has to be at right angles to the cut line. Is this one any better?

 

[Carl Prentiss]

I don't know what you just said. You don't need a block. You set the fence at 45*. I'm just trying to illustrate my idea that the domino does not have to be at right angles to the cut line and sometimes can provide more integrity being parallel to the long edge.

 

[CNX]

Thank you all for sharing your thought.

In the end this is what I did, which worked.

> While my miter saw is still in the same angle, I cut a scrap (but straight) MDF with about 4-inch width.
> I sandwiched the narrow stock with the pieces of the MDF and flush the surface of the mitered end.
> Then I can get a reasonably good reference surface to register Domino.

Several points, though.
> Because my stocks were milled from thicker ones, I didn't have MDF or other stocks with the same thickness. Therefore, I had only the narrow stock to register the Domino fence. It was OK, though.
> Thinking back, I could have done what MDMuller suggested. A much better approach! Not sure why I tried to use the height fence. I didn't need it....
> My biggest mistake came from a totally unexpected place (as usual), which I want to share with you.

- I aligned the center of the stock and a mark on a leg, which are reference lines for Domino
- When I tried to bore a mortise into the narrow stock with a miter angle, I decided to offset little bit to the obtuse-angle side because I'm afraid the mitered mortise bored through the side of the narrow stock
- Of course, this shifted the rail position on the leg  [mad] I'm stupid....

Charlie, what you drew is exactly what I tried to do in the beginning and I believe non-Domino approaches may do this way. However, because Domino's cutter always comes out at the right angle from the Domino face, it is quite difficult to bore a mortise at non-right angles. Yes, the fence can be tilted at any angles, but whatever the angle of the fence, Domino always bores mortises at the right angle of the face. I guess that is what Peter and Wrightwoodwork meant.

 

[darita]

I know we're talking Dominos here, but wouldn't biscuits work well here? 
Oops sorry...forgot these are narrow pieces.

 

[Carl Prentiss]

Glad you found a workable solution and hope you took a few photos. Looking forward to seeing the final outcome.