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Old 05-16-2019, 09:39 PM
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Table Stabilization Question


So, I am building a very primitive table with my non-existent woodworking skills.

The purpose of this table is to replace 2 cardboard boxes that I use to put my mouse, mouse pad and forearm on as I sit at the computer.

I have a wood table top that is 21 inches long, 10 and 1/2 inches wide and 1 inch thick. That is the size I want it to be.

I have 4 legs that are 25 inches high, 4 and 1/2 inches wide and 1 inch thick. Basically just rectangular planks of wood.

My question is, from a birds-eye view, in what orientation should I attach the legs to the top for maximum stability?

Should the 4 and 1/2 inch width of the legs be used along the long sides of the top or the short sides? Or would angling them in some way, be better?

I don't have the skill to make them shoot out at an angle past the tabletop and I don't have the room for that anyway, as the table will sit right next to my chair in the perfect spot.

Additionally, would adding weight to the bottom of the legs lower the center of gravity and therefore make it harder to tip?
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Old 05-16-2019, 10:59 PM
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The table would be more likely to tip by falling over it's short side. So the worst arrangement with the legs at the corners would be to put the long side of each leg parallel to the long side of the table. It would be better to put the long side of the leg perpendicular to the long side of the table.

I don't know if angling them so they were 45 degrees to each side would be better. It would be better if the table top were square but yours certainly isn't.

And yes weights on the leg bottoms would make it less likely to tip.

Last edited by OldGuy; 05-16-2019 at 10:59 PM.
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Old 05-17-2019, 12:06 AM
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Thanks!!
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Old 05-17-2019, 12:23 AM
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Thanks!!
The table is more likely to fall over on it's long side (I think this is probably what oldguy meant....). It will be more stable with extra weight at the bottom of the legs.

I think that if you put the weight symmetrically, it doesn't matter much if you put the weight closer or farther from the center, so you should arrange the legs in the way that you think makes the structure stronger: your big problem is going to be bracing.
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Old 05-17-2019, 02:36 AM
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How do you plan to attach the legs to the top?
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Old 05-17-2019, 06:49 AM
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I would angle the legs. These 4.5" x 1" legs are very stable one direction and unstable the other direction, particularly if attached using non-existent woodworking skills.

If you line up the legs parallel to each other, the instability lines up and the whole table will wobble in that direction. If you angle the legs at each corner, the unstable direction of one leg is offset by another leg that is very stable in that direction.
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Old 05-17-2019, 07:46 AM
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Saw the legs in half lengthwise and put one on each side of each corner.

Last edited by UnwittingAmericans; 05-17-2019 at 07:50 AM.
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Old 05-17-2019, 07:46 AM
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bob++ I was just going to drill pilot holes straight down and then put in 2 inch #8 steel wood screws, while also using a little wood glue.

Cheesestake, did you mean angle them so that the ends are facing the center of the top or the opposite, cutting across the corners of the top?
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Old 05-17-2019, 08:57 AM
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You can get 90 degree corner bracings or brackets for very cheap at the hardware store. They may help stabilize things.

Caveat: my woodworking skillz are probably a half-step above "nonexistent."
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Old 05-17-2019, 09:02 AM
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Cheesestake, did you mean angle them so that the ends are facing the center of the top or the opposite, cutting across the corners of the top?
I think it works either way. I'd set them in place and see how it looks to choose. You get more room to stash something underneath if you cut across the corner, it may have a smaller profile look, less boxy, if you go center to corner.
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Old 05-17-2019, 10:05 AM
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bob++ I was just going to drill pilot holes straight down and then put in 2 inch #8 steel wood screws, while also using a little wood glue.
That will be a very weak connection between the legs and the top. A significant sideways force applied to the table top might cause the screws to rip out of the legs. Screws are weak when driven into end grain and glue is also weak when applied to end grain. There are a lot of good ways to connect legs to a table top, but with "nonexistent" woodworking skills, using angle brackets may be the simplest.
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Old 05-17-2019, 10:12 AM
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I would make a frame simply screwed together at the corners out of 2" x 1" boards, slightly smaller than the top and screw the legs to that. I would also arrange two legs one way and two the other, screwing horizontally through them to the inside of the frame in the corners. The top could then be glued on.

Last edited by bob++; 05-17-2019 at 10:13 AM.
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Old 05-17-2019, 10:33 AM
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Oh my. This isn't going to end well. I know what I would do, but with nonexistent woodworking skills, I'm not sure if it would help.

First, I would get something other than a 1x5 for the legs, especially if you are screwing into the end grain. It'll rip out in no time. Maybe some simple 2x2s. Then, I'd use the 1x5s as aprons (An apron is a board that is perpindicular to the table top. It will connect all four legs together and will provide angular stability. Here's a picture https://s3files.core77.com/blog/images/553330_81_59321_GXZGr6mUo.JPG) The simplest way to do it in something close to a correct manner is to use 'pocket holes' You can get a pocket hole jig fairly inexpensively and look up on youtube how to use it. They're very simple. (If you just can't figure that out or don't want to spend the money, you can try to use screws at an angle behind the aprons and they'll look bad, but they'll be the back side. They also will not be as strong.) Then, use little L brackets to screw the aprons onto the top.

Last edited by senoy; 05-17-2019 at 10:36 AM.
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Old 05-17-2019, 10:53 AM
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I would run an extra set of planks to run around the base of the legs and then screw in some cross brace cables making an X on each side.
Like this
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Old 05-17-2019, 12:45 PM
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That will be a very weak connection between the legs and the top. A significant sideways force applied to the table top might cause the screws to rip out of the legs. Screws are weak when driven into end grain and glue is also weak when applied to end grain.
I want to expand on this a little. The joint between a table top and its legs is probably, apart from chairs, the one place in ordinary furniture that takes the most stress in ordinary use, because of the large lever arm involved in a long leg trying to pivot on a short joint. Thats why most tables have aprons to which the leg is attached. In the OP's proposed geometry, there is a 1 inch wide leg 25 inches long, butt jointed to the table top. Now suppose someone pushes on the table top with a horizontal force of 30 pounds, in a direction perpendicular across the 1" leg. The top edge of the leg where it's attached to the table acts a fulcrum for the 25" lever that is the leg, with the resultant force pulling the leg away from the top. If the screws are in the center of the board, 1/2 inch from the leg edge, the horizontal force will be amplified by 25/.5 = 50x. So there will be a force of 1500 pounds pulling the screw from the weak end grain.
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Old 05-17-2019, 01:02 PM
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He's replacing 2 cardboard boxes, not building a fuckin' arm wrestling octagon.

Last edited by UnwittingAmericans; 05-17-2019 at 01:02 PM.
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Old 05-17-2019, 01:36 PM
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The table would be more likely to tip by falling over it's short side.
<=== DUMB sorry this should read long side. The rest is OK.


Quote:
Originally Posted by OldGuy View Post
So the worst arrangement with the legs at the corners would be to put the long side of each leg parallel to the long side of the table. It would be better to put the long side of the leg perpendicular to the long side of the table.

I don't know if angling them so they were 45 degrees to each side would be better. It would be better if the table top were square but yours certainly isn't.

And yes weights on the leg bottoms would make it less likely to tip.
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Old 05-17-2019, 02:18 PM
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Originally Posted by UnwittingAmericans View Post
He's replacing 2 cardboard boxes, not building a fuckin' arm wrestling octagon.
That's true, but end-grain joints are incredibly weak and (s)he's putting them on thin long legs. Plus, (s)he's putting forearm weight on the structure. There's zero doubt in my mind (and I would warrant the minds of many other posters) that it will collapse and likely in not too long of a time. That's just wasting his/her time and the wood. The suggestions given aren't about over-engineering with full-blind dovetails and interlocking miter joints. It's suggesting adding aprons or triangular bracing.
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Old 05-17-2019, 02:32 PM
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I think extra bracing can be subject to feel. If the table feels wobbly after screwing it down, some angle brackets or cross braces can be added.
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Old 05-17-2019, 03:11 PM
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Did you know you can use a meme generator for quick free image storage, lol?

Make 8 legs out of your 4, and then do this in each corner:

Screw the top to the legs and use an L brace to attach the legs to each other right under the top and in however many additional places you want. You could conceivably brace the legs to the top also.

Bottom view (the white blocks are the legs):

https://i.imgflip.com/318se5.jpg

Last edited by UnwittingAmericans; 05-17-2019 at 03:14 PM.
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Old 05-17-2019, 03:43 PM
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Thanks for all the input everyone. Back to the drawing board!
  #22  
Old 05-17-2019, 07:19 PM
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As I read this, I am looking at a coffee table I built about 45 years ago. It has a skirt all around made of 1x4 inch oak. The skirt boards are mitered into each other, but butt ending would have worked as well. The legs are 2x2 posts and are attached to the skirt by glue and pegs. The pegs were cut from 1/4" birch dowels. There are 8 in each corner, 4 of the skirt boards into each other and 4 into the legs, that is 2 into each side. It has lasted 45 years and shows no wobble. Of course, stability is not an issue since it is 40x40 and maybe 20" high.
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