A design question?

[Luggage]

I am the president of a club and we wanted new tables for our room. I designed and fabricated them. There are three types:

All have a piece of lacquered good one side plywood as tops and T base style legs they differ in the design of the part that attaches to the tops

2 tables are 3' X 8' the top part that attaches to the table top is in the shape of an X made out of angle steel. These tables are great no problem at all


2 are 2' X 8' with offset T bases and 1 is 3' X 5' these three tables do not have an X where they attach to the table they just have angle going across the width.

These are the tables with the problem they are not stable for the obvious reason of wobbling from side to side. Something I or my design consultant should have foreseen!

Now the question is how to fix them? I want to add more metal to the part where they attach to the top to make it an X like the other tables.

My fellow club members think that we should drill holes through the table tops and use nut and bolts to attach the tops to the legs (um unsure if this plan also includes adding more metal to the legs also?)

I am opposed to this second plan because I don't like any Idea that will make the tops unsmooth since it is a place to do homework. They say we can fill them with putty. The putty Idea worries me because what then if we want to take the tables apart and then those spots will be unlacquered.

I also wonder if you drill holes in a straight line across a table and then someone sits on the end won't that weaken the wood and increase the chance of breaking? it is only 5/8" plywood


I would appreciate advice and opinions

[doyle]

I say just go with the tried and true method of the X-brace. It's a simple fix, either by tack-welding or by drilling holes for nuts and bolts.

[mjpliv]

If you want to attach to the underside try using stud inserts with a wood thread on the outside and a 1/4-20 thread for a bolt on the inside. Most large building supply outlets should have them. Most are 1/2" deep so there will not be anything pentrating the surface. You just have to make sure no one uses a bolt long enough to come up through the top. Here is one type to give you an idea -

http://www.richelieu.com/products/affichesouscateg.asp?n=O&t=C&s=C01E01C&l=&nom=%22E%22+type+nuts&section=produits&filtre=&mast=M&SearchQuery=&source=

[Luggage]

Thanks for the advice, I really want to do the x brace but think the insert idea would be a good Idea to try with it for added strength :D

[Dragon]

One word.

Gussets.