Timeline for Can I get some tips or criticisms of this couch plan?
Current License: CC BY-SA 3.0
9 events
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| May 6, 2015 at 6:42 | comment | added | Ast Pace | @LeeG The main reason for the difference in out calculated results is what structural engineers call end conditions. You chose the fixed end condition, I chose the floating floating option - also the structural engineer's choice (it's not totally free, but it is the more conservative option). The actual deflection with the concentrated 250 pound load would be in the order of 0.4 to 0.5 inch, which gets bouncy. If the distributed load is a little as 50 pounds per foot the deflection goes to 0.7 inch. | |
| May 4, 2015 at 5:41 | comment | added | djvs | Of course I would probably rotate the long horizontal pieces 90 deg as suggested - since 95% of the time the load is going to be vertical instead of lateral - which I suppose means the mortise and tenons would be placed in the upper half of those pieces. Then the question is how to best do an angled joint into the back one, upholding the angled back of the seat surface - I guess an angled mortise and tenon also. | |
| May 4, 2015 at 5:37 | comment | added | djvs | This is a really interesting approach (and I think it would look great if the mortise/tenon joints were visible in the exterior and planed/stained nicely). I love the idea of using the mortise and tenon joints for the connectors in the middle, I suppose all the coil springs could just be placed on the superior surface of the horizontal seat plane. My point of confusion is with the fact that the whole back plane is angled in this design - I am pondering how I could have it constructed out of two pieces, so that the upper back could be angled, but the leg of the back would be vertical. | |
| May 4, 2015 at 5:37 | vote | accept | djvs | ||
| Apr 28, 2015 at 20:17 | comment | added | LeeG | It is possible. I stood on the middle of a 2x4 laid on edge and it didn't seem to deflect at all. In this setup, the load would be distributed (not necessarily evenly) across both of the long seat members. I used the Sagulator to check, and to get the .25" of sag, it needed 200 pounds per foot. My numbers were for a single 250 pound person in the middle. If we assume four 250 pound people, that is about 1/4" of sag, assuming all the weight is on the front piece. If we assume some of the weight to be on the back piece, it reduces it to about .1" | |
| Apr 28, 2015 at 20:06 | comment | added | Ast Pace | @LeeG Sorry, but I must contradict you on the deflection of the long seat members. If the intermediate legs are removed and the stringer is turned 90 degrees, the sag with a 250 load at the middle is more like a half inch, so much that it would be springy. (checked this theoretically and experimentally.) | |
| Apr 28, 2015 at 16:32 | comment | added | LeeG | That is not a complete drawing, I was just illustrating the changes I was proposing to the structure. There will be an additional horizontal brace between the top of the front leg and the middle of the back leg. | |
| Apr 28, 2015 at 16:30 | comment | added | Aloysius Defenestrate | +1 for elegant design, but strongly suggest triangle bracing at the angled back legs... imho, those look like looming disaster if left as drawn | |
| Apr 28, 2015 at 14:17 | history | answered | LeeG | CC BY-SA 3.0 |