Layout for Using Dominos to Attach Tops with Tenons

[TomInNC]

I would like to make some speaker stands like those below. I would like the column to be hollow to run speaker wire down to the base and out to the receiver. My plan is to just domino the column together to create what's basically a long box. I know I could just screw the base and top on, but that would be too easy, so I want to attach them with dominos. Aside from measuring very carefully, are there any tricks for laying out mortises for attaching bases and tops with dominos? Mortising the column is easy enough, but it is less clear how to best transfer the mortise locations to the top/base to properly align them. It seems like the issue is similar to using tenons to attach a chair seat to the legs, but I've never made a chair, so that isn't much help. 

 

 

 

[Ronn W]

I think that that is a tough layout for a Domino - in the middle of a flat surface.   I would consider using wood dowels and using dowel centers to set the locations.

[pkinneb]

I agree with Ronn on this one dowel centers would make this easy peasy.

[Von]

I think I've seen the equivalent of dowel centers for dominos, but I'm not finding them readily. In any case, agree dowels would seem a good alternative.

[gee-dub]

Here's an example of dominoes in the middle of a flat surface. 

Using scrap blocks for an offset fence make this pretty intuitive once you learn to think upside down and backwards .  Seriously, it all boils down to using a common reference surface for the mating mortises (mortisi?).   You can also use one tight mortise and other loose-fit mortises to make lining things up easier.  there will not be a terrible amount of stress on this joint, right?

[wtnhighlander]

Mark the center point for the domino on the ends of the box, the tap a small finish nail int the mark. Snip it off about 1/8" above the surface, and it becomes the 'dowel center' to mark the overhanging top & bottom pieces.

Drill and appropriate pilot hole to make the cut off nail easy to extract.

[Coop]

I use @gee-dub method as well. As you can see, all of his dominos are not aligned with the outer edge of the bottom piece. Here’s a simple video to demonstrate. There are others out there as well.

Well, I just thought I could copy and paste the intended video. Don’t know if it’s me or the fact that it is a YouTube video. Search case work using the Domino on you tube. 

[TomInNC]

Thanks for the feedback on this. For some reason I didn't get the normal email notifications about new posts. 

For either the domino or dowel approach, should I be concerned about glue joints constraining the wood movement of the top and base? When I attach table tops, I use z-clips, figure 8s, or buttons to allow for movement. If you look at the picture, there appears to be a lot of cross-grain orientation. Is it ok to use a glue joint here because the dimensions are smaller (maybe 9 inches wide) than what you would have for a table top?

[wtnhighlander]

My experience so far has been that pieces that small rarely move enough to cause trouble, but environmental conditions in your neighborhood may be quite different.

[Von]

Rule of thumb I learned was 1/8" of movement across the grain per foot (yes, this is a gross simplification) and not to worry about anything less than a foot.

[Coop]

@Von, this seems a little extreme but maybe not. Is this from personal experience or research. And I’m sure it also depends on one’s location. 

[Von]

On 5/13/2024 at 10:11 PM, Coop said:

@Von, this seems a little extreme but maybe not. Is this from personal experience or research. And I’m sure it also depends on one’s location. 

Hi Coop. It was a rule of thumb I heard.... somewhere. Norm Abrams/NYW perhaps?

"Research" would definitely be an overstatement, but it's worked for me and I've looked at actual wood movement charts over the years and while it's clearly a gross simplification it hasn't struck me as obviously misleading. As someone smart once told me, all models are wrong, some however are useful :-)

And I'm curious, does it strike you as too much or too little?

 

[gee-dub]

  Doweled from underneath, not Domino'd but maybe a good example.  I have a 7/8" thick, 23" wide cherry top on a media cabinet.  We get pretty mild humidity swings around here.  I used a modified breadboard that is more of a tongue and groove.  The tongue runs near full length.

I mortise the front and insert a decorative spline.

 

The dowels enter from below, penetrate the breadboard, the spline, and enter the breadboard again but do not penetrate the top.

The front dowel fits tight to maintain the front profile throughout the year.  The middle dowel is centered in a 1/2" long slot while the rear position is centered in a 1" slot.

Sorry about the bad pic.  I was using my phone and firing blind.  The movement of the top makes the tongue to groove relationship at the rear go from a slightly recessed tongue to an 1/8" or so of proud tongue. Probably about 3/16" overall.  This method works well if a piece is not mounted to a wall and a constant front elevation is desired. 

The Domino has width settings that easily allow a similar construction mid-panel or anywhere else for that matter.

[TomInNC]

Thanks. That's a nice piece. Regarding the dowel connection, do you only apply glue to the dowels? Or do you run glue along all of the contact points between the top and the base? I'm assuming just the dowels to allow for movement, but I wanted to be sure. 

[gee-dub]

On 5/17/2024 at 7:07 AM, TomInNC said:

Thanks. That's a nice piece. Regarding the dowel connection, do you only apply glue to the dowels? Or do you run glue along all of the contact points between the top and the base? I'm assuming just the dowels to allow for movement, but I wanted to be sure. 

Thanks.  There is a journal here.  The position I want fixed, the front in this case, gets glued for the full dowel length.  I even put an inch or so of glue at that position on the T&G.  The slotted positions do not get any glue on the tongue; they have to be able to allow movement.  I put a spot of glue on the last portion of the dowel to go in just to fix the dowel in place.