Spec a aluminum I beam

[linacfse]

I have a aluminum Spanco portable A-frame gantry crane. the I beam is 3 1/2" x 6" and a span of 8 ft. It is rated at 2000 lbs. I need a wider span,12ft. I have found a 4" x 8" I beam with .270" web and flange. where would I look, how do I calculate how much weight I can lift/ support with little to no deflection / sag.

 

[Bill D]

Gorbel says 8x4 0.271
Sounds like you have what is needed. I have no idea if crame aluminum is special alloy or heat treat. I doubt it.

Gorbel Aluminum Gantry Crane, 1-Ton, Ht. 7.5-10.5 ft, Span 12 ft

Gorbel Aluminum Gantry Crane, 1-Ton, Ht. 7.5-10.5 ft, Span 12 ft

www.ergonomicpartners.com

 

[reggie_obe]

Isn't all that information on the Spanco website? Multiple widths and heights available in most every capacity.

 

[boslab]

E for aluminium, section modulus, second moment of inertia, simply supported beam, deflection.
Not a simple plug and play, requires some number crunching, as far as lifting appliances best left to an engineer, aluminium is a particularly troublesome material due to fatigue and such, steel is much more forgiving imho.
Mark