Needed: Plan review

[revchris]

I've been asked to build a TV stand and a matching pair of speaker stands by a friend of mine.

Here is a PDF of the plan (note: the plan is drawn on 8.5'x11' paper so that I don't have to figure out how to get Coreldraw to scale the distance markers).

The basic plan is a 2x2 oak skeletal frame with 3/4" oak veneer plywood banded with iron-on veneer. The TV stand also has three slide-out component trays, each mounted on two center-mount-style drawer slides. While I was drawing the plans, I also added the diagonal braces on everything, because I decided it would be a shame to have it collapse.

Does anyone see anything that they'd recommend changing? So far, the only thing I think it's missing is a cable port or two (to get wiring up to the TV through the table top). Simple solutions would include punching a standard cord grommet or two through the top, or putting a scallop or two along the back edge.

I need to provide an estimate by Tuesday. As is, I'm looking at $300 for materials, and I haven't decided on labor charges yet.

Comments

[therealattentiv.livejournal.com]

Sorry I missed the Tuesday deadline for comments, but I hope these are still useful. The pdf didn't quite show up completely for me (i.e. no measurements), but I think I get the idea. I'd have to say that the diagonal braces are probably overkill, but I tend toward the engineering overkill too. I like my stuff to hold up to people in lampshades dancing on them... :)

It looks like you have a skirt around the top edge of the legs below the top. I think if that skirt is attached to the legs securely enough that it will provide the stability that you need. One thing I like to do in designs like this is to have the skirt on the back be a little larger than the sides and front (this works especially well if there are solid sides). The slightly larger skirt on the back provides the extra stability you need to keep the carcass from racking. I also often add a skirt at the bottom around the location of the shelf (ASCII art commencing...)

Side view (back is on the left, front (cut away) is on the right):

(key: '*'=shelf, '\'=cutaway, '|'=leg, '='=side skirt, 'x'=back skirts)

*******\
********\
xx=====\
xx======\
xx=======\
xx|||
|||
|||
|||
|||
xx|||
xx|||
xx=======\****\
xx=======\****\
xx========\
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The larger lower skirt not only helps prevent racking, but it also helps keep things from sliding off the shelf. If the depth of the legs permit, you can gain additional stability by insetting the skirt into the leg.

[therealattentiv.livejournal.com]

Ooooh, that formatted so nicely... lol

If you can't get the idea from that mess and are interested, let me know and I'll provide a better image...

[revchris.livejournal.com]

That is quite a mess.

There is no skirting planned - everything except the top and the three slide-out trays are full-cut oak 2x2. In quick 3-D drawing form (without the top or component trays), it looks like this.

The top and component trays are 3/4" oak plywood with veneer ironed on over the cut edges (no raised edging) because that's what they want. The plan also requires that the sides to be open everywhere possible because of ventilation concerns.

Finally, the feet are designed more like skis - the ends are bevelled and the sides are rounded over so that there is a chance to actually be able to slide this around on the carpet without having to empty it or carry it to move it. I've got the skis fully below the lower front & back rails, but I'm thinking about notching them about an inch deep so that they only hang below the rails by an inch, and not two inches.

[revchris.livejournal.com]

Dimension-wise, the tv stand frame is 68"w x 22"d x 18"h, and gets topped by a 70"w x 24"d piece of plywood (leaving a 1" overhang), and the speaker stands are 16" cubes with 18" square tops.

The tv stand had three 20"w x 12"h x 24"d component bays, with about 11" of clear space beacuse the tray boards and their drawer sliders work out to be about an inch tall.

[therealattentiv.livejournal.com]

Is there a reason for this particular frame design? How do you intend to fasten the joints?

If the runners only serve a purpose when sliding it around, I'd recommend not using runners. For the few times it would be slid around I'd build a couple of smallish quicky pine skis for them to slide it around on (i.e. lift one end and slide the ski in, then lift the other end and slide the ski in. Slide the thing around and remove the skis. The runners may make it harder to get and keep the unit level.

The strongest design and easiest to brace to avoid racking is to have the top resting on the top of the legs and have the legs run straight through to the ground. In this design you have four joints between the top and the ground instead of one. Each of those joints is a 2x2 joint that is subject to racking/twisting concerns.

[therealattentiv.livejournal.com]

It's been my experience that some vents at the bottom and top of the back panel (along with an open front) provide plenty of convection ventilation for even the hottest video and audio equipment. So I don't think it *has* to be a completely open design. An open design means the wires are more visible...

[revchris.livejournal.com]

The frame design is due to it being similar to the table they're currently using, and the fact that they like that design. I've also decided to bring the skis up an inch (so that they only hang an inch below), so that if it gets moved it drags in the carpet less, and depending on how things are going, may skip the end bevels entirely.

Planned joinery is a combination of biscuitry and screws. Combined with the fact that they don't want the screws to show (or any obvious plugs from covering the screws), I'm trying to line things up so that I can put the screws in vertically and tie everything together via the legs, so that the screws are either covered by the top (for the screws that attach the top frame to the legs) or up from the bottom. I'm also planning on some screw heads showing on the back so that I have more options for screwing down the bracing.

It's also become a learning project, as Janet wants to help with the construction so that she can learn more of how it all goes together.

[therealattentiv.livejournal.com]

I had this sneaking suspicion that there was a reason it was designed that way ("to match existing furniture" was tops on the list). Then the only thing I'd recommend is learning from the existing furniture to see what was done to stabilize and strengthen it.

You might check into pocket screws. You could pretty easily get 2 side-by-side in a 2 inch space and they'd be on hidden sides of the joints. I'd recommend using gorilla glue since it has much stronger holding characteristics. I'd also recommend that in place of biscuits you make rectangular oak wedges (3/8" thick x 1.25" high x 2" long) and cut (with a drill, chisel, or (plunge) router) mortises into both parts of the joint. In my experience, biscuits primarily serve to align pieces rather than strengthen them. I try to use slightly larger wedges or splines of the same wood where possible. Make sure to try a couple of samples first to get the sizing right since the gorilla glue expands slightly and you don't want to split the joints.

If you do skip the end bevels I'd still recommend relieving the end a little. You have oak end grain on the end of each of the runners. The end grain can catch and split off (not as bad as cherry or mahogany - but bad enough to worry about). You could just use a router or sander to round over the bottom front/back edges of the runners by 3/8" (slightly less than the depth of average carpet) so it would tend to slide without catching.

Visually, if their existing furniture doesn't have the corner bracing, you could minimize them by making them triangular wedges in the corners instead of full corner braces (with an empty triangular area in the middle of the braced pieces). They would be less visable that way.

And speaking of triangular wedges, that is another way you could strengthen the design and prevent racking. Under the top (and maybe under the bottom shelf) you could add in triangular corner wedges between the corner joints of the horizontal frame pieces.

If you *really* wanted to get weird, you could look into some of the hidden Japanese joinery. You end up with *very* tight joints without any visible signs of support... but that's probably fun for another day. :)