Elastic modulus on round bar

[craigclick]

We’ve been asked to provide a mock-up and quote for a retail display. My intuition tells me that while interesting, it’s not practical.

Putting aside the fact that while it could not be free-standing, and even a solid base may not be enough without some type of upper plate, my concern is what size of round bar would be needed to have enough elastic modulus to remain vertically straight.

From the images attached, you can see that 29 pieces of wood, 80mm x 220mm x 30mm thick, each weighing 0.38kg make-up a vertical 2320mm section. The overall size is 2320 x 3960mm.

While 4140 3/8” bar would be preferable, I’m not even sure that ½” bar would be sufficient to keep it all vertical.

I’m not asking for anyone to do the math for me; what I’m asking for is an intuitive off-the-cuff response from those that have much more experience than me.

Opinions? Thanks

 

[GC_Hopi]

Looks interesting. You will need to create some system to stiffen the whole thing. The most logical place would be where you have the square tube. Either add some cross bracing using cables or plexiglass panels. That would make it rigid in the out of plane direction. Then you would need a solid base.

 

[craigclick]

I agree; it needs a base, and the square tube could help with support. The thinking is that the rod is threaded on the ends, one end into a steel base, and at the top a nut. We just did a small mockup with 16 pieces of wood and four 1/4" steel rod. Four high with a hidden joint that kept them at 90 degrees so they wouldn't rotate. The rod only entering a base of plywood. Surprisingly solid; but then, it was only 32cm tall.