[G-Spot]

OK been looking for steel.

New price is $1:15 Kg

I managed to find a scrap yard with a great selection of beams at $0:70 Kg so I am going to take the 50% cheaper option and use it to get thicker bigger beams than I could afford new.

They even have railways tracks, so tempted to use them and make my own bearings, 1000Mpa and hardened by trains, 100 years of stress relief.

Now I must choose a size, I need 10m and my budget is for 500kg.

Any recommendations for web and flange thickness ?

Is it better to go for beam height or flange thickness? I know that flange thickness is better if you want it to be stronger but web thickness is important for twist and buckling.

I think for a machine base/frame then resisting twist is just as important as load bearing strength. They are not going to be used for load bearing in the direction of gravity.

I want to go for I beams because they are easy to model in FEA and easy to increase stiffness later.