Domino placement rails and stiles

[DaveInPa]

I’m building a fence gate with milled 2x3s and using 2 dominos per joint. The orientation of the rails and stiles are different than typical face frames so I’ve never comes across this. I easily added 2 mortises to the end grain of the stiles (verticals) referencing from each side. Then added top mortise on rails using same setup and it all fits beautifully.

Now I’m stuck on how to accurately position to create the bottom mortise. Hard to explain exactly s9 here is a picture of the structure assembled and a close up of the rail and stiles. The bottom is the rail and I’ve penciled in where I need the second mortise.

 

[smorgasbord]

Well, the first thing is that you should rotate the mortises 90º. The way you have them oriented results in long grain to end grain glue surfaces, which will be weak. Then the question is whether the stile is wide enough to support two dominos side by side, each cut referencing the nearest face. For stock this thick, the DF700 is probably the better tool, but you might be able to make it work as long as you're still using two dominos per joint.

 

[cdconey]

I agree with [member=77266]smorgasbord[/member], rotate the dominos to go with the grain.  Use a spacer off of the top face ( between stock & Domino Fence) to get your double mortises lined up.

 

[ChuckM]

Orient the dominoes as per smorgasbord's advice, then mill the twin tenon as in (A) if the stock is thick enough according to the 1/3 rule, or (B) if it isn't.

Using a spacer as suggested by cdconey -- with only one and the same registration face --  is one way. Alternatively, you can set the fence height only once based on either of the tenons, and use the same fence setting to mill both tenons, registering on the opposite registration faces.

[attachimg=1]

 

[DaveInPa]

Thanks all!

I never thought about the domino grain direction with the mortised grain direction before but it makes sense.

 

[Packard]

I’m a dowel guy, so I don’t get involved with the orientation, but I do agree with Smorgasbord in that matter.

I do have to consider where to place the dowels.

Dowels (and dominoes) enhance the strength of the joint in two ways.

The first is how much lateral pressure the domino can handle until it breaks.

The second, and far more important in my opinion, is the tensile strength.  It’s ability to resist pressure to pull the dominoes out of their mortises.

On a fence gate, the downward pressure is cantilevered out and the pull will be primarily from the top of the joint.  So the dominoes should be positioned off-center and moved towards the upper par of the joint.

I don’t have any data to suggest how far off center it should be.

 

[Willy Eckerslike]

The rail sits on top of the stile in this instance.  Given that I've never seen that construction method before it means I've either not being paying attention (quite possible), or that there a valid reason.

I'm no mathematician/physicist but instinct tells me that the pulling upward force on the joint (pivoting on the inner corner of the stile) in this design will be greater than the pulling outward force on the stile (pivoting on the lower corner of the rail) in a conventional construction.  Happy to be proven wrong.

Is there a particular reason to build the gate this way?  I've got two large gates to build soon and I'm open to suggestions.  All the gates and doors I've made in the past have been using the traditional stile and rail arrangement.

 

[DaveInPa]

I’m far from an expert on this but my thinking was the rail should sit on top of the end grain of the stile to provide some protection from the end grain being exposed.

 

[Packard]

I retract my advice in my earlier post.  Not because I think it is in error, but because there is so much controversy on how to build fence gates. 

I looked on YouTube and there seems to be a dozen or more ways to build a fence gate that does not sag.  And some of the posts indicate that others are all wrong. 

I don’t think I know enough about it to comment at this time. 

I am showing the YouTube search so that the Dave can make up his own mind. 
https://www.youtube.com/results?search_query=how+to+build+a+wood+fence+gate

 

[Crazyraceguy]

I’m building a fence gate with milled 2x3s and using 2 dominos per joint. The orientation of the rails and stiles are different than typical face frames so I’ve never comes across this. I easily added 2 mortises to the end grain of the stiles (verticals) referencing from each side. Then added top mortise on rails using same setup and it all fits beautifully.

Now I’m stuck on how to accurately position to create the bottom mortise. Hard to explain exactly s9 here is a picture of the structure assembled and a close up of the rail and stiles. The bottom is the rail and I’ve penciled in where I need the second mortise.

As Packard said, I'm not going to debate gate building practices, but I can help with your original question, as far as placement to your scribed line.
The fact that you have already done the end grain side may complicate it some, but still do-able.
To make this easiest, cut the ones on the end grain part with the fence of the Domino set at 20mm.
This will put the centerline of the mortise 10mm from the edge.
Then you clamp another board, as a reference surface, right on the pencil line. Stand your Domino on end, with the base plate against the board (on the pencil line) and cut. This will put the mortise 10mm from the line.....and it fits [smile]
If you have cut your end grain mortises anywhere other than 10mm, you just have to compensate for that difference from your pencil marks.

 

[DaveInPa]

Thanks - so I used the 36 board height setting which means my mortises are 18mm from the edge. You are saying that the domino BASE PLATE is exactly 10mm from the mortise center. So I need to set my reference line (clamp a board) 8mm beyond my line so I’ll get a mortise 18mm from what should be my edge.

Said another way…the domino is manufactured with the mortise 10mm from the edge of the base plate so use that to make my calculations…

 

[Crazyraceguy]

Thanks - so I used the 36 board height setting which means my mortises are 18mm from the edge. You are saying that the domino BASE PLATE is exactly 10mm from the mortise center. So I need to set my reference line (clamp a board) 8mm beyond my line so I’ll get a mortise 18mm from what should be my edge.

Said another way…the domino is manufactured with the mortise 10mm from the edge of the base plate so use that to make my calculations…

Yes