Custom cabinet work design/construction help needed

[William Lai]

I am relatively new to the forum, and this is such a great resource and community, that I'll like to ask you for some help on a problem for a project I'm tackling.

I’d like to build a frame for a purchased murphy bed mechanism (see here (http://www.murphybedsonline.com/build_supremo.php?pageID=hardware)). The frame is basically a tall book case without shelves, 85 1/16” tall, 16” deep, and 65” wide. It’ll be secured against a wall, and the bed pulls down in front of this hoop. The issue is that the basement location where I want to put this bed is about 85 1/4 plus or minus 1/8" due to uneven floors. That means that there’s no way I can tilt up the case after it has been assembled, as I’ll need 86.55” for the diagonal of the case. I think the only way it'll work is assembling it upright in the room, and then slide it against the wall.

It seems like the biggest challenge is selecting a joint between the side and the top/bottom pieces that are a) securable while the case is upright, and b) that naturally lends itself to be as square as possible. Clamping will be a challenge, too, I think, so I’ll likely use glue as well as screw to alleviate any need for clamping.

Options I’m considering using singly or in combination:

- Biscuit joints to help with alignment
- Or are dowels a better choice?
- Pocket screws or confirmat screws from the side, to secure the case mechanically, as well as act as clamp while glue dries.
- Dado the side panels to help with alignment
- Nailing on a 1/4” back panel to ensure squareness and add structural strength

One thing I’m wondering is besides a dado, are there better joinery techniques that I can use that are more appropriate to the task? Some sort of lock joint? Any thoughts or ideas on how you’d tackle this is much appreciated.

Thanks.

[Carl Eyman]

Has the basement a finished ceiling now? If the joists were exposed, I'd suggest tilting it up between the rafters, rotating it 90* (if necessary), putting it in place, and doing your ceiling work later. Alternatively, could you assemble the frame in two ell shaped pieces horse them in position, and only have to deal with 2 corners in an awkward position?

[William Lai]

Carl: Unfortunately, it is finished and so there's no way to sneak it in between the rafters. However, the two Ells idea is a brilliant one! I am pretty sure I can rotate two Ells in place, and it'll literally cut half the challenge away. Thanks for the help!

[Alan Turner]

Never having done this won't stop me from a suggestion or two. If you glue it together, then getting it out of there someday will probalby be impossible. And, with so little clearance, you might need to disassemble it to service the wall or its contents. A leak? Electrical line? Thus, my thought would be to make it KD all the way.
How about barrel nuts, inserted from the sides. A very slight rebate would self align it. Or possibye a glue bloctk type of arrangement to hold the barrel nuts, if clearances of the bed unit would allow for same. Insert the screws through the sides, top and bottom, of course, and assemble in place.
You could rebate the back by 1/4" for a back that would hold it square, but I would screw the back in, without glue for the reasons noted.
Barrel nuts are available from Lee Valley, I think, and other industrial suppiers also.

A routered lock miter joint would be difficult to assemble by sliding in place, and you lack room to do it otherwise. I am assuming you are thinking of plywood for this piece.

Good luck.
Alan