On Jan 31, 4:35*pm, "Steve B" wrote:
I'm building a lift, probably 1,000 $ max, but mostly 500 or less. *Is there
a chart that gives different structural configurations and their relative
efficiencies?

i.e. .............. *a bar joist design
* * * * * * * * * * * a pyramid with lifting point at the apex
* * * * * * * * * * * two poles with a right angle peak point of attachment
and one horizontal purlin
* * * * * * * * * * * a plain truss shaped span, pitched to the roofing,
with diagonal bracing ............

16' wide span, verticals 8', then up with the framework. *I actually need
two so I can lift my boat entirely with straps. *Weight of boat, about
1500#.

I have been googling, but no luck yet.

Material would be 3 x 3 x .120" tubing MIG welded together, and gusseted
mostly wherever possible, and lateral bracing to help side loading.

TIA

Steve

Most of that sort of thing is found in second and third year ME texts
as student problems. Get the solution guide. Also engineering
mechanics under statics.

Stan