# Looking for advice on preventing racking on this table



## LVWorkshop (Aug 30, 2020)

Picture shows the desk I'm building. You can tell it has some racking issues. The legs are made of 1.5" square tubing. My current plan is to extend a piece of tubing across the bottom to brace them. The other picture shows how I attached them to the table. I drilled oversized holes and then screwed the legs into the bottom of the desk. The desk itself is 54" wide and 28" tall. I was wondering what your thoughts were on if this would be a good enough brace and if the legs are attached securely enough.


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## RichT (Oct 14, 2016)

You need some horizontal bracing to make the legs rigid. Actually, with the way you intersected those two triangles, you have some cool options.


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## SMP (Aug 29, 2018)

I'd probably make a stick out of the same wood that connected the two diamonds.


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## CaptainKlutz (Apr 23, 2014)

+1 need horizontal bracing between legs.

+1 fancy chunk of wood between legs would look nice and help with racking.

IME - When using medium sized wood screws with oversize holes to attach metal plate to table top, the flex in screws/wood will still allow some racking movement. How much depends on stiffness and structure of wood bottom. Obviously a 2" thick slab is less flexible than 3/4" plywood. Using larger bolts that don't stretch helps too.

IMHO question really becomes how stiff you do want table legs to be? 

If you want to completely eliminate racking movement, need to have 2-3 rigid metal horizontal braces between legs, removing the wood flexibility from equation. Make the base rack resistant, and the table won't rack.

If it where mine; would weld a metal cross brace in middle of leg openings, and 2 smaller 1×1 tube braces between the top mounting plates just outside your mounting screws. Might get away with only one wide (5-6" plate) cross piece under table, but would need couple of screws to eliminate bending. With the triangle created with 2 separated square tube top braces, helps resist corner to corner racking and will not need to attach top to cross braces.

YMMV
Best Luck!


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## LesB (Dec 21, 2008)

Captain Klutz has some good ideas.

I took you pictures and lightened them so I could see the structure better. I think I would add a braces (wood or steel tub on each side from the center of you leg structure up to the center of the desk top.


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## bilyo (May 20, 2015)

A straight brace between the Xs would eliminate a lot of the wiggle. However, what LesB said will make it almost wiggle free. Triangles are always stiffer than rectangles.

Nice desk. Good job.


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## CaptainKlutz (Apr 23, 2014)

+1 LesB 45° braces for racking fix. 

As a very active member of Klutz society in America, tend to overkill designs in house with kids or any member of Klutz clan? LOL

The amount of wiggle removed by mounting two 45° braces to table bottom, will depend on amount of flex in table bottom panel. If that table has nice torsion box inside between drawers, 45° braces would work well.

But if the bottom panel flexes, and legs can slide on floor; the legs will have in/out vibration mode. Instead of racking, you will get legs 'walking' around when top flexes.

If it were mine, and wanted design to use 45° braces; would run metal center brace between leg brackets directly underneath table top, and attach the 45° braces to metal cross brace. Maybe over kill? 
Again, how stiff you do want table legs to be?

School of hard knocks story:
I made a behind sofa table with simple metal legs attached to a slab, not unlike your table. Customer had subwoofer underneath table which sat on smooth decorative concrete floor. Silly table walked around a bit and hit sofa all the time. Had to re-design to make base rock solid to prevent any slab flexing from extending through the legs. Can't tell length of your table, environment/use, or flex potential; just sharing my worst case as reference.

YMMV


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## LVWorkshop (Aug 30, 2020)

Thanks for the feedback. I like the idea of adding horizontal braces to the bottom and top. Originally I was going to just add to the bottom but adding at the top isn't going to be seen and would strengthen everything.


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