Table design

[Pappaw]

Any suggestions of how to build a table that you may want to move easily if need to be. I do not want to build one that will be permanent so to speak, but in case the time came to move to another house. The one I am rebuilding at this time was just a 3/4" thick top piece with folding legs, 30" deep and 15' long and over time the 8' center piece warped and I put on 1"x2"x3/4" supports around the edge to correct that, but still had a small warp in it and now want to rebuild it with the proper strength and supports to keep all level and square, but be able to disassemble to move easily. The 3/4" thickness of the top was just to be able to hold the screws to attach the folding legs, so I guess it could be thinner this time!

[tankist]

a friend of mine built N scale table out of pink foam. says it very light and easily portable. but i would think he will need to be extra carefull with it as it is bit fragile

[imatt88]

Wow, thats interesting..

[tjcruiser]

The key to stiffness on any structural member is what engineers call moment-of-inertia, or section-modulus. Basically, think of an I-beam ... most of the material that's doing the work is in the top and bottom flanges of the beam ... the web (vertical member, connecting the flanges) locks the top and bottom flanges together, with one acting in tension, and the other in compression.

The point here is that stiffness goes up in a cubic-power relationship with increasing height of the web (or separation between the top/bottom flanges).

In building any structure, concentrate the "meat" of material as far away (top and bottom) from a "neutral axis" as possible, and then connect things with a light but rigid framework.

In considering the pink-foam table, stiffness is achieved via the "effective plate" of the main foam panel, and the lower-most section of the stiffeners glued to the bottom. One could have carried through the discussion above and glued a SECOND flat panel to the bottom of the stiffeners to yield a dramatically stiff panel, when considering that it's made of foam.

At a recent train show, a club (CT, I think ???) tours around local shows with their huge narrow-gage layout. It's all sub-assembly components that are built I-beam (or I-panel, really) style ... 1/4" ply top and bottom, each separated by about 6" of space reinforced with local stiffeners. The stiffeners themselves are also 1/4" ply, but drilled throughout with large (4" diameter) lightening holes. These tables-on-the-go are extremely light, but incredibly stiff and rigid for their weight.

TJ

[Ron 43]

That's a great idea for a small layout.

[Onei]

Hi

You could use a normal board and strength with timber struts underneath. You can then perhaps buy some trestle legs that the board would sit on. This would mean you could avoid having to attach collapsable legs to the board itself. Or perhaps build a frame that the board can sit on?