knock-down settle joinery opinions

I'm in the middle of knocking off a Stickley knock-down even arm settle. Since this thing is almost 8', I'd like to add some cross bracing to it rather than just rails along the front and rear for the upholstery frame to sit upon. If this was a glued up piece, I'd use pinned mortise and tenons. However, this is a knock-down piece and I'd like to keep it as easy to transport in the future as possible. Essentially, it'd be nice to have the lower rear and front rails be separate for moving.

Since I've never actually seen an original, and I'm going off of pictures and dimensions, I have no idea how they dealt with this at the start of the 20th century. The ones I've seen are not knock-down and so there's a center divider in place to keep the front and rear from spreading. Thoughts?

Picture so you can see what I'm dealing with.

https://photos.smugmug.com/Woodworki...IMG_8958-L.jpg

I assume when you say 'cross bracing' you are trying to prevent racking. Triangles are your friend.

So how about a 'X' brace? A pair of 'slats' with a cross-lap joint in the middle. It could span from front to back of the lower rails and perhaps 1/3 of the L-to-R distance. Should be relatively hidden from view. This could also serve to prevent rails spreading as you allude to with a center divider - depending on chosen joinery.

That leaves the joints where the 'X' meets the rails at an angle:

1. Sliding dovetails? Pockets may be easy, but angled tails might be a challenge.
2. Thru- or Blind-mortices in the rails; angled stub tenons on the brace ends? Shouldn't need glue and once rails go into end frames, the 'X' will be captive, but may allow spreading.
3. Dowels or dominoes? (A bit less difficulty but same issues as mortice/tenon.)
4. Angle iron bracket and bolts or knock-down 'keyed' bed frame hardware? Have to decide how best to 'angle' them into the rails.
5. Might horrify you to suggest pocket screws?

#1 would be my preferred, but #4 wins simplicity/ease.

I'm not so concerned about racking. The through mortises are draw bored, except the ones with knockdown pins and those are tapered. It moves about the same as my workbench. I'm concerned, however, about the front and rear removable rails from pushing apart under load. Also, since you can fit a whole lot of people on an 8' sofa, I'd like to not have to do any repairs. :D

I'll have to draw what I'm thinking about. That may help.


Oh, also this is a single bottom cushion. So part of it is to reinforce the frame for that.

Quote:

---

Originally Posted by mike stenson

I'm not so concerned about racking. The through mortises are draw bored, except the ones with knockdown pins and those are tapered. It moves about the same as my workbench. I'm concerned, however, about the front and rear removable rails from pushing apart under load. Also, since you can fit a whole lot of people on an 8' sofa, I'd like to not have to do any repairs. :D

I'll have to draw what I'm thinking about. That may help.

---

Assuming a vertical z-axis, I'd agree that in the x-z and y-z directions this is positively tank-like. But the x-y axis, with that 8' lever arm, will fold like a cheap suit (pardon my cheap metaphors).

A simple front-to-back rail, perpendicular to the existing rails, made with sliding dovetail ends should be hidden, easy to build, install, and remove. ...Won't stop x-y axis racking, but if that is no concern.... speed on!

And perhaps the seat frames will serve to prevent this x-y racking? I'm flying blind on this part.

Quote:

---

Originally Posted by Malcolm McLeod

Assuming a vertical z-axis, I'd agree that in the x-z and y-z directions this is positively tank-like. But the x-y axis, with that 8' lever arm, will fold like a cheap suit (pardon my cheap metaphors).

A simple front-to-back rail, perpendicular to the existing rails, made with sliding dovetail ends should be hidden, easy to build, install, and remove. ...Won't stop x-y axis racking, but if that is no concern.... speed on!

And perhaps the seat frames will serve to prevent this x-y racking? I'm flying blind on this part.

---

Yes! it's that front to back rail segments. Those are what I'm trying to wrap my head around. I've been pondering sliding dovetails. They'd be easy enough, but will they be strong enough.

Quote:

---

Originally Posted by mike stenson

...dovetails... will they be strong enough.

---

Material? (looks to be cherry rails?) How many braces and how often will it get knocked-down & moved? 1 or 2 braces are probably sufficient to last forever if the settle is never moved (Ikea is only good for 1 assembly:mad:!)

If worried about dovetails, I'd look hard at the knock-down hardware for bed rails.

Quote:

---

Originally Posted by Malcolm McLeod

Material? (looks to be cherry rails?) How many braces and how often will it get knocked-down & moved? 1 or 2 braces are probably sufficient to last forever if the settle is never moved (Ikea is only good for 1 assembly:mad:!)

If worried about dovetails, I'd look hard at the knock-down hardware for bed rails.

---

Yeah, all the build (so far) is cherry. I have no idea how often it'll get moved. I was planning on having two braces splitting the open area into thirds. At this point, I'm probably just into analysis paralysis.

edit: and thanks for talkin' me down. My dog just agrees with me.

If you want knockdown capability use this bed frame hardware for your stringers:
Attachment 517607

For your cross supports use these:
Attachment 517606
I used similar hardware for the wood parts of these day beds.
Attachment 517610Attachment 517609

You could also use threaded inserts. I would recommend that if you use threaded inserts that are steel, not brass.

Do you have the bed frame and mattress in house yet? It would be a real frustrating event if it didn't quite fit.

Quote:

---

Originally Posted by Tom Bender

Do you have the bed frame and mattress in house yet? It would be a real frustrating event if it didn't quite fit.

---

It's not a bed, it's a settle. I'll be providing the seat frame to an upholsterer.