Joint Wars: Half-Lap vs Bridle and House or not?

[smorgasbord]

That's great, too - especially the tusk tenons on the splayed legs. How did you cut the mortises for them? I don't know if you can tell from my photos, but I "cheated" and cut them like I cut the square dog holes - flat face with a router and then laminated a side piece on. I didn't own mortise chisels at the time, not that I'd be any good with them.

I also like the built-in shelves with no drawers - easy access to everything on them.

What are the dog-holes for?

Did you see my earlier post on a back-fence zero-clearance cube? Might not work with that factory fence you have there, though.

 

[jeffinsgf]

That's great, too - especially the tusk tenons on the splayed legs. How did you cut the mortises for them? I don't know if you can tell from my photos, but I "cheated" and cut them like I cut the square dog holes - flat face with a router and then laminated a side piece on. I didn't own mortise chisels at the time, not that I'd be any good with them.

I also like the built-in shelves with no drawers - easy access to everything on them.

What are the dog-holes for?

Did you see my earlier post on a back-fence zero-clearance cube? Might not work with that factory fence you have there, though.

I cheated, too. The legs and stretchers are 3-piece laminations. With very careful cutting and alignment, I made the mortises by leaving a gap in the center and made the tenons by making the center long. The only "real" mortises are the ones for the tusks. I chopped them out with a mortise chisel. Before you're too impressed, the legs and stretchers are sassafras. It's pretty soft stuff. Strong, lightweight and easily worked. A little tougher to cut than white pine, but only a little.

I use the dog holes for all sorts of stuff. I made the bench tall, because I hate bending over when I'm cutting. I've found all kinds of jobs I prefer at this height. I keep a bunch of track clamps stashed under the top and we have a wedge clamping kit made for 2096 tables that I use a lot.

I'll have to check out the zero clearance cube. I need to give that saw some love. I hardly ever cross cut on a table saw now that I have it dialed in.

Now that we've completely hijacked your desk thread...back to our regularly scheduled programming.  [big grin]

 

[smorgasbord]

Back to desk design, in this other thread I had started exploring these Nakashima designs:https://www.festoolownersgroup.com/general-friendly-chat/seeking-your-ideas-for-a)-slab-desk-and-b)-small-night-table/msg728304/#msg728304

But I had also wanted at least one drawer, which I didn't want above my lap and didn't want all the way to the right. So, started looking at designs, such as a few posts above, with a slab side and a 3-4 drawer unit. And that was kind of clunky, so I was going to taper not just the slab leg, but also the drawer unit, which led me down an angled dovetail rat-hole for the drawers. And then my wife said the design was getting too heavy looking.

So, I thought - why have both a big slab leg AND a big drawer unit? Instead of clever joinery to support the top from a thick slab leg, why not support the top from the drawer unit? Easy to attach the top to the drawer unit (could even use plain ole screws, but I won't), and the width of the drawer unit is at least at much as the two legs (one slab one square pole) in the Nakashima design, above. So, then all I'd need is a base stretcher on the ground to stop tipping.

I started to draw something out, and still will, but here's a somewhat ugly similar design:

My top will be that thicker one-piece of cherry posted in the other thread, and I'll recess the drawer unit in from the side about 20cm to clear the "notch", and the base stretcher will be proportioned better, but that's the general structural idea. My wife hates it, but I think she's not able to imagine the wood differences.

Thoughts? Remember, this table is just about 5' wide and almost 2" thick.

 

[rvieceli]

[member=77266]smorgasbord[/member] if I get a vote and mine probably doesn’t, absolutely not. Even with a nice piece of cherry on the top the drawer unit looks like it should be made out of plywood.  [sad]

One option if make your drawers a rolling file cabinet and keep it at arms length. Roll it over when you need it 

If you are convinced that you need the drawer assembly as part of the desk, then it needs to have some special treatment to make it “worthy” of the nice cherry.

Here are a few folks that do wonderful work that would make the drawers a nice addition.
https://www.caseyjohnsonstudio.com
https://www.casey-mccafferty.com
https://www.joelescalona.com
https://www.jorybrigham.com/sterling

Ron

 

[rvieceli]

Here are the Instagram links which usually have more ups and in process pics than the websites
https://www.instagram.com/caseyjohnsonstudio?igsh=Y3oyOHZ1OWN6bGF0
https://www.instagram.com/casey__mccafferty?igsh=d3J0NHlreGJjcWYz
https://www.instagram.com/joelescalona?igsh=MWprMGNxbmY1dnJlZA==

R3MmQ2

Ron

 

[smorgasbord]

[member=77266]smorgasbord[/member] if I get a vote and mine probably doesn’t, absolutely not. Even with a nice piece of cherry on the top the drawer unit looks like it should be made out of plywood. 

I would do something different for the drawer stack - I was talking the structural aspect of the construction.

And this is one way Nakashima integrated a drawer stack in his designs:

Suppose I took that and more firmly attached the top to the drawer carcase, maybe with a larger base, then replaced the slab leg with a floor-level stretcher as in the earlier picture I attached?

 

[Michael Kellough]

My 2 cents is to go back to the original design and create a stand alone drawer unit later.

A drawer for the slab table should be invisible to someone walking in. Like a literal pencil drawer with wood runners. Consider that a pair of heavy lineman’s pliers will fit in a drawer less than 3/4” deep. What do you really need to put in the drawer other than even thinner stuff? Make it wide if needed since it will be very lightweight. I think even Bluetooth keyboards will fit in a 3/4” drawer?

Maybe the drawer unit could be short and could crouch (separately) under the table. Detached, and not so heavy (bulky) that you can’t pick it up and move it when fully loaded. No wheels required, instead, short legs that allow some air (let you see the floor) underneath. Short enough that you could put a couple bulkier things on top of the drawer unit and keep the main table clear for longer.

 

[smorgasbord]

Even with a nice piece of cherry on the top the drawer unit looks like it should be made out of plywood.  [sad]

Yeah, my wife nixed that one right away, even though I made it clear I was talking about the structural aspects and nothing else. It's a lesson to me that presentation matters, and why homes with "good bones" but needing work can be bought cheaply.

Anyway, I'm not great at Fusion360, but here's what I drew up:
[attachimg=1]

I'm still not happy with this, but I think it communicates just enough of where I'm going with this. A tapered-side drawer cabinet on a Nakashima-style half-lap bottom stretcher base.

 

[Packard]

Back to the joinery…

I could not find an illustration online, so it will have to be by my description.

Years ago, I read a magazine article where they illustrated an ultimate strength joint. 

It was a box/finger joint made with 1/8” fingers using the maximum cut depth on his table saw.  On my saw, that would be 2-7/8” deep.

So on a 2-1/2” wide stock that would be 20 fingers.  I do not recall how he got the glue into the voids though. 

1/4” or 3/8” thick fingers would be much easier to glue and I would probably go with that.

My ceiling height would limit the board lengths to about 40”, but that would probably be fine for a desk height (28” - 29”).

This would provide far more glue area than any of the previously described joints. 

I’m trying to figure a jig to allow a router to cut this joint.  I can’t get to 2-7/8” depth with 1/4”, but I think I could find a router bit that has a 3” cutting length straight cut x .375” diameter.  I still can’t visualize the jig though.

 

[smorgasbord]

The length of the fingers in a box joint is typically set by the thickness of the other piece of wood, since this is normally done for boxes (!) and thus right angle joints.

For the kind of base construction I'm talking about here, the joints are "Tee" joints, not right-angle joints. The only way I can imagine having ⅛" fingers that are 2&⅞" long for Tee joints is to think of it as a multiple mortise and tenon joint where you have a lot of thin (⅛") tenons into equivalent mortises.

And while a bridle joint can be used for right angle joints, extending that to be a multiple-bridle joint is, I think, what you're talking about with lots of long, thin "fingers."  I suppose I could build a base that is essentially an open, 3-side box of 1.5" thick members, but that's really just a thick U-shaped frame, and yeah, that might be strong, but also not the look I want, nor does it solve the cross-member aspect, which is needed to stop the table from spilling to one side. Except for using 2 of the U-shaped frames, but then I might as well just buy a pre-made metal U-shape base and bolt it on like so many epoxy river people do today.

Maybe I'm totally misunderstanding you, in which case a picture or link to such would be helpful.

 

[Packard]

Back to your original image.

Bottom right joint.  A simple bridal joint, then drill from the bottom a 3/4” x 8” hole and epoxy a 3/4” x 7-1/2” steel machine bolt.  The hole should be slightly oversize but tight enough that you can still have the threads bite into the wood.  Epoxy on the threads and the hole. 

I considered just a straight piece of steel rod, but with the epoxy I suspect that there will be enough hydraulic resistance to make inserting the rod nearly impossible.

3/4” might be bigger than needed and 5/8” or 1/2” might be fine.  You are not going to find any performance data for this type of joint.  The rod will primarily keep things from racking side to side.  The bridal joint will be needed to keep things together.

In my imagination, this works perfectly.  I have no real life experience with this amalgam joinery.

 

[luvmytoolz]

I've been looking at these pics for some time, and I've gotta say it, I think if you're going with a design like that I'd be putting some copper or brass folded sheet to protect the timber from serious scuffing, cause no-one I know would have the self control to not be resting feet and shoes on that bottom brace.

 

[smorgasbord]

[attachimg=3]

... no-one I know would have the self control to not be resting feet and shoes on that bottom brace.

Yeah, the Nakashima dining room table we have has a similar bottom stretcher and yes, it does show some signs of wear from shoes after over 50 years of daily not-overly-respecting family use. But, it's not bad or ugly and George N. himself talked about wear being a good thing, giving the piece character.

That said, our family now doesn't wear our shoes indoors, this is a desk for my use, and given the top is asymmetrical, my design has the bottom stretcher located further away from where I'll be sitting. Maybe it shows in this Fusion360 renderings:
[attachimg=1]

[attachimg=2]

 

[jeffinsgf]

I think the asymmetry helps both the function and the aesthetic.

But, I'm wondering about the large tapered leg. Is that a slab with the center cut out or an assembly of 4 pieces? I'm thinking I would like it better as a solid slab.

 

[smorgasbord]

I think the asymmetry helps both the function and the aesthetic.

But, I'm wondering about the large tapered leg. Is that a slab with the center cut out or an assembly of 4 pieces? I'm thinking I would like it better as a solid slab.

Funny, I did the cut-out specifically because I wasn't happy with a solid slab leg, feeling that was taking away from the solid slab top. My original idea was to cut out the leg from the other slab I ordered and keep the free edges there, too. That immediately felt too over the top distracting. Then cutting the solid slab out proved difficult given all the void and cracks, so I ended up ripping the other slab into some various width boards according what I knew I needed (eg bottom stretcher), and what made sense given my resaw/planing width (350mm), while trying to have cracks/voids either in the middle or cut off. The tables I saw from Nakashima tapered the sides of the slab leg, and I liked that.

And then since I'd be gluing up the slab leg anyway, I thought a Limbert-cut-out kind of thing might be less heavy and add some simple design appeal. Like Limbert, it wouldn't be a frame - the grain in all pieces would run vertically (actually semi-vertically for the stiles), so attaching to the top would be easy (unglued dominos and DF700 connectors).

At this point I'm going to cut my scraps to validate that the size and location will give the top good support and then take the design considerations from there. I did think I could add a thinner contrasting panel in the cut-out, or could do some edge treatment (like chamfering), but one thing at a time I guess.

BTW, the top is pretty roughly drawn. I traced a photo in Fusion, but didn't bother with all the points and their tangents to get matching hard corners, etc. It is pretty close to the right dimensions overall though.

 

[smorgasbord]

In a recent video, Jon Peters decided to use half laps, just to keep it simple...

The full build video is out now, and the half-laps are anything but simple:

He seats a thick dowel in the vertical pieces so a large lag bolt run in from the top has something other than end grain to bite. Yick. And then he uses buttons to attach the top, yet the grain direction of his top and base run exactly in the same directions. So, no buttons needed.

I would think a bridle joint would provide strength without the need for metal, and without the need to seated dowels for the metal.

Unfortunately, I'm going to be away from the shop for a few weeks, so won't get to finish my prototype for a while.