Drop leaf bunk

[LMarsh]

I'm looking for some tips on making bunks in my current build. I lack experience in real wood working, furniture making or cabinetry. I figure others could weight in on this with some good ideas. Even knowing the right words and names for the parts or mechanisms is a challenge when searching online.

I'm making 5' bunks for my kids that will be side to side at the very front of the teardrop. I want the upper bunk to drop down about half way through its depth to convert both beds into a seat. It will basically function like a drop leaf table or shelf would. The bunk will be made out of 3/4" plywood and I want it to be basically indestructible. Having two kids bouncing, climbing, and jumping on it is a given. So it should be able to withstand hundreds of pounds safely while still looking stylish. I will probably reinforce the edges of the plywood with 3/4" steel angle (or at least along the front edge with a wide hardwood board) and bolt the hinges all the way through both materials.

I'm looking at either continuous hinges or just some door hinges. I don't know which will be stronger for this kind of application but heavy duty door type hinges are readily available while continuous hinges strong enough might be harder to get. I'm not a wood worker and can't figure out which is the strongest type of hinge. Is spreading out the weight over a long 5' hinge better or is just using a couple heavy duty hinges? Vintage Technologies has a heavy aluminum hinge that might work. http://www.teardroptrailerparts.com/Heavy_Duty_Piano_Hinge.html

The next issue us keeping the bunk in the up position for sleeping but I don't think I want a locking, folding, or bench seat style specialty hinge underneath. For one there will be little fingers touching everything in the lower bunk and these types of hinges probably won't look good or will get in the way of head room. If they're lower profile they probably won't be strong enough. I could support the bunk above with a couple chains or rods coming off the ceiling or walls which could also double as a way to keep a sleeping child from rolling off the edge. I'm not really sure about that idea so I'm leaning more to having some kind of decorative swing away support on each wall.

Kind of like this but using two from the sides and leaving a small gap to allow the bunk to swing past it when they're folded in:


Any thoughts? Thanks in advance!

[Louisd75]

I'm going with how Camp Inn does their forward bunk. Basically, the top bunk sorta floats on a shelf running around the front of the trailer. The front edge rests on the shelf, the aft outboard corners use barrel slide bolt latches that extend out and rest on the shelf atop steel pads. There's a vertical support for the wall/roof that keeps the bunk from sliding aft. The first decent picture I found of it online is huge, so I'll link it below:

http://imgur.com/hpb1icU

The pads I refer to are just below the light switch visible in the picture, about halfway up the door opening.

The couch part consists of a panel that folds up after you drop the top bunk onto the lower bunk, as shown literally in this video:

https://www.youtube.com/watch?v=EPI9ImpkYqI

If you were set on the front edge of the bunk being attached with a hinge, you could still use the barrel slide bolt latch idea on the aft outboard corners to hold the bunk up. I'm planning on essentially copying the Camp Inn method since that's the way the front of my trailer curves. The curve makes it difficult to use a hinge on the forward edge.

- Louis

[tony.latham]

Here's another idea. This folding slide-out impressed me:

viewtopic.php?f=50&t=59086&start=195

Tony

[LMarsh]

I've seen the Camp Inn design before and even watched the same video. I like their teardrops. I don't think a completely removable bunk will work with my design and I'd like to do more than have it rest in place so I can drive with it up, but then again I guess it wouldn't bounce around too much. The drawer slides definitely won't work for me but its an interesting design. Slide bolts might be useful though to hold some swing down legs to support it...

[aggie79]

Door hinges are stronger but piano hinges will work better. The real issue is not the strength of the hinge itself, but the strength of the material that anchors the hinge. A piano hinges has more fasteners, spread out over distance that will distribute the load and lessen the chances of the screws pulling out of the material.

You could use steel, but instead I'd use a 1" x 2" (nominal) poplar on edge (longside vertical) to frame the plywood. That will be more than strong enough.

For the swinging brackets, I would use 3/4" plywood instead of the hardwood as shown in your picture. By using plywood, you won't have to worry about making the wood joints of the triangle.

[LMarsh]

I had the same thoughts about the hinges and material. Its hard to get a strong weight bearing hinge when the walls and bunk are only 3/4 of an inch thick. I'm thinking now some fold down legs might be the best way to take the weight while not getting in the way. My better half thinks I'm crazy and that I should just make it a solid platform.

[Kmucha16]

You could still use the hinges, but instead of screws holding it in, you could put through bolts in. Of course that depends on what's on the other side of your attachment wall.

Kevin

[M C Toyer]

I have a full size (56 x 78) bed that folds down, a la a Murphy Bed. The base is 1/2" plywood framed with 1 x 4 on edge perimeter as Tom suggested plus 1 x 4 "picture frame" and two 1 x 6 braces on the underside to attach the vertical top perimeter and t-hinges.

The extra perimeter height keeps the foam mattress in place but the front edge is mounted low allow a soft entry / exit. For bracing when down for sleeping I have a full length tube across the front with sliding rods at either end that slip into pockets on the trailer walls to secure the bed. It easily supports two adults..




There is a full width storage locker beneath the bed which serves as seating or a single day bed when the full bed is raised. The silver locking rod can be seen at the top of bed frame.

[LMarsh]

Yeah I'm not sure what I'm going to do exactly with the folding bunk idea. The Murphy bed is exactly what I wanted to do with the back part of the interior for the adult sleeping section so as to kind of hide the bedding away. It was going to fold down over the table and seating area, which I still made, but again my wife talked me out of all the extra work. So now it will just have bench seating on three sides of the table. I definitely don't have tons of time to spend on figuring out these more elaborate ideas but since I'm already building it I figure I might as well build it the way I'd like it to be.