Square Tubing Size For Brewstand

[EagleDude]

I don't know how necessary it is, but I drilled a hole in the bottom of my short pieces near the burners just to make sure I didn't end up with an exploding tube.

[andy77]

not so much the size, but thickness plays more into it,

Anyone?

[Kbar]

not so much the size, but thickness plays more into it,

Anyone?

Ran the old defelction calcs for curiousity reasons. I used two techniques, but what it comes down to is that you increase the moment of inertia thus decreasing the beam deflection. Deflection is based on the equation; Y=(Wx(l-X)*(l^2+x(l-x)) / 24*E*I*l

The moment of inertia is where the geometry of the tube comes into play. We need ot make this maximum to reduce any deflection. 'I' for a square tube is (A^4-B^4)/12. A is the outer dimession and B is the inside dimension of the tube. B=A-2*thickness. In summary when you increase the tubing thickness and the size of the tubing, you get less deflection. All that work to state the obvious. But the other poster that said the large dimension fo the tubing did not matter, was not correct. 2" tubing with a 1/16" wall is actually better, for deflection, than 1.5" tubing with a 0.125" wall.

Please check my calcs. I am rusty at these. Been out of engineering school for 15 years now and I am a Hydraulics and Pneumatics system design engineer.