Breadboard End with Dominos

[FS7]

And that should be reason enough to use longer tenons.  Breadboard ends use pinned tenons for a reason - to prevent the ends from pulling away from the mating member with seasonal changes in humidity.  You can compensate by cutting the breadboard with a concave inner edge but why not just build it right to start with?  6 x 50 mm Dominos for a breadboard on the end of a dining table is far too light for my liking.  For the OP's project, yeah, OK, maybe.  But what's so hard about just routing a deeper mortise?  3/8" x 1.5 - 2" is not hard to do with a plunge router and double edge guide or template and bushing.  

John

My attitude has always been "it's wood, if it breaks, then I can fix it." Obviously that's not always true, but I've done a lot of things as experiments (always with things I keep, or give to immediate family with their awareness) and I rarely if ever see additional problems. Interestingly enough, I did run into gaps like you describe on a breadboard end once, but as far as I know it was not due to seasonal changes. In fact, I simply cut the breadboard off and re-did the same design with larger tenons. At that point I had only the top done, so it was just a fancy panel waiting for the rest of the work (I finished that piece after two years last year) and I could monitor it over time and fix again if needed. As far as I can tell it was an imperfect mating surface, not humidity changes. Of note would be the fact that the current version of that has been stable for three years in that direction while doing what a breadboard should in allowing for seasonal expansion. It is also pretty uncommon for wood to warp in that dimension after drying. That I believe is called "crook" and almost always happens when wood is drying to EMC, not from seasonal humidity. I could be wrong.

You're right, it's not that much harder to add in that safety factor. I simply contend that it's not necessary and an 8x50 Domino breadboard configuration will be more than enough. It is not hard to find plenty of forum threads and articles discussing the perceived necessity of spring joints in breadboard ends, based at least in part on the fact that dry wood won't normally move that way. Thus perfectly flat surfaces (much easier to achieve than a good spring joint) should be sufficient. My attitude in the beginning was "if this works, this will be great, because it's so much faster and easier," and I believe at this point it does work. I know it's the traditional way to do it, but it does seem like a "belt and suspenders" approach based on potentially quite improbably scenarios,

[lincmercguy]

I decided to try both methods with some scrap oak. Cutting the tenon material was pretty easy after doing some metric conversion. I glued the tenons in tonight so I'll have to pin them tomorrow.

I did learn a couple of lessons already.

1. Don't get lazy on supporting for cutting the mortises. They ended up at a slight angle. I'll have to do better on the production side.

2. Drill for the pins before cutting the mortises. 

I could see how a plunge router with a spiral bit would be better for this, but I don't have a festool router that works with a track. I'd have to build some kind of jig to hold it in place for an edge guide. The fact that this is a small project actually works against me here. I think a drill press and using a bit with a drill to widen the holes will work for this one.

We'll see how the rest of the test goes tomorrow.  So far, I'm leaning towards wider tenons, but not going through the work to setup mortising with a router. If I was building a dining table, it would be a different story.

   

   

   

[fredhargis]

I think what you've done there with the wider tenons will work just fine, once you iron out the bugs you came across..

[FS7]

I decided to try both methods with some scrap oak. Cutting the tenon material was pretty easy after doing some metric conversion. I glued the tenons in tonight so I'll have to pin them tomorrow.

I did learn a couple of lessons already.

1. Don't get lazy on supporting for cutting the mortises. They ended up at a slight angle. I'll have to do better on the production side.

2. Drill for the pins before cutting the mortises. 

I could see how a plunge router with a spiral bit would be better for this, but I don't have a festool router that works with a track. I'd have to build some kind of jig to hold it in place for an edge guide. The fact that this is a small project actually works against me here. I think a drill press and using a bit with a drill to widen the holes will work for this one.

We'll see how the rest of the test goes tomorrow.  So far, I'm leaning towards wider tenons, but not going through the work to setup mortising with a router. If I was building a dining table, it would be a different story.

One thing I came across yesterday when thinking about John's advice was stainless steel round stock. In the interest of removing as little stock as possible from the Domino (were you to use that) I would suggest using blind stainless steel pins from underneath. This is not dissimilar from knife scale assembly, so it should work. But with a 22 or 24 mm width tenon, you could have more than half the material remaining on either side even if you allow for 3/8" total movement. In addition, with 1/8" pins, you could center them 1/2" or 5/8" or so from the edge of the piece, allowing for strength in that direction as well.

I would think this would work well and in addition, you could more comfortably cut the expansion slots with a Dremel spiral cutting bit.

[Handplanesandmore]

There are many many youtube videos showing breadboard ends done with the domino machine. Their execution may vary, but the majority stick with factory tenons, the way I'd use too if I'm to make a dominoed breadboard end.

If a wide tenon is desired, I wouldn't spend the time making it on the tablesaw and router table. I'd use two festool tenons in a wide mortise instead. After all, why is a domino machine used in the first place for the breadboard end? Simplicity and speed.

If I needed to use a router, a tablesaw, make some jig etc etc, I might as well go the traditional way of making a breadboard end. Which may indeed be necessary if the dominoes aren't the suitable way of doing the breadboard project. Just to cater for seasonal movement rather than a structural requirement (such as a wide breadboard end for a big dining table), I don't see why the factory dominoes can't do the job.

But I look froward to learning from lincmercguy's findings.

Simon

[lincmercguy]

"If a wide tenon is desired, I wouldn't spend the time making it on the tablesaw and router table. I'd use two festool tenons in a wide mortise instead. After all, why is a domino machine used in the first place for the breadboard end? Simplicity and speed.'

With my test piece, I was actually surprised how quickly I was able to produce the tenon material. It took about 15 minutes. I planed a piece of scrap oak to slightly thicker, ran it through the drum sander to get the final thickness (it helps to have a test fit mortise cut for this), jointed the edge, cut to width based on my test mortise, then just ran through the router table with a small round over bit, and cut to length. Since most of that it setup, I should be able to produce a larger batch in the same amount of time.

Cutting wider mortises didn't really add additional time, I just added marks 1/4" on each side of my original to make a 1/2" wider mortise with each cut. On the breadboard side mortises that need to be wider to allow for movement, I used the same marks, but set the Domino to its widest setting.

I might be a tenon fabricator convert now for certain applications.

I think tonight I will cut fresh breadboard ends from scrap to try drilling for the pins first and getting my mortises properly perpendicular to the edge. It's not like I'm running low on scrap pieces.

[Handplanesandmore]

It took about 15 minutes.

You have quite an efficient setup, I must say. If I set up my tablesaw and router to get a batch of some good fit tenons, it must be at least half an hour, or more likely 45 minutes to an hour! That compares to 30 secs of grabbing the double tenons.



Simon

[lincmercguy]

The tablesaw was just to cut to width, so it's usually ready to go. I did the round over routing on the router table, which was fairly quick to setup. I'm sure it wasn't an exact fit for the round over, but close enough to be structurally sound.

I'm much more efficient in my shop than I was when I was working out of my garage a couple of years ago.

The drum sander (new for me) helped sneak up on the proper thickness more quickly as well.

I'm sure with the size of this project, factory tenons would allow enough movement and there isn't that much stress on the parts to begin with. It's a hope chest for my wife's niece that I was commissioned to build, so I want it to be nice.

[lincmercguy]

BTW, I think my woodworking has improved over the past couple of years being able to throw together a test for an entirely new to me technique in an evening and get it about 90% right. I've kind of made it my primary hobby since I got my shop built. New tools and toys can help, but it's also taken me a while to get confident with the Domino I got earlier this year.

[jteneyck]

That's such a small piece that I'm sure the Dominos will be more than sufficient.  And now that you've seen how easy it is to make loose tenons why would you buy Dominos again?  

The one thing missing on your breadboard end is the stub tenon.  It keeps the two piece in alignment from edge to edge, not just where the tenons are.  It also provides for a daylight free appearance in case the end pulls away a little.  It's just really hard to beat how breadboard ends were designed.  And if you make them this way you don't have to figure out how to route a deep mortise in the end of the field.  



Only in the side of the breadboard end, for which I have the perfect machine, but a router and edge guide will work fine, too.







John