Jim - two of the channels "converted" to an I beam 4 in. high, 1.584 * 2 inches wide with a flange thickness of .296 inches and a web thickness of .184 * 2 in. and 16 ft long showed a max stress of 25064 psi & 1.281 in. deflection with a 2000 lbs center loaded weight. You didn't use the "uniform loading" option, by any chance?
Hul
Jim Wilk> > Jim - for the free center 16 ft version, take a look at an I beam > > with the
Those are the values I got for one center loaded 4" x 16' channel, which I then halved for two in parallel. Thanks for checking.
The flanges of this W6x9 beam are very slightly tapered by about
1/32", AFAICT through the rust. They are a reasonably good match to the outer taper on the channel if I increase the center spacer to 3/4" which aligns the outer edges of the beam and channel. There's the rust and some welding and torch cutting flash to grind off before fitting them together more precisely, but it looks promising. I could suspend the W6x9 upper flange from the shed roof beam with U bolts and use the one assembly for both applications, if properly reinforced for both sagging and hogging.I should add a warning that a gantry track suspended from tripods can collapse in many ways from single point failures, such as a leg sinking or the load swaying. The soil here is compacted glacial till with a good bearing strength and I have large trees to tie the tripod tops to. I tested the concept free-standing but have used it only where I had trees and a shed to stabilize the track and tripods. Pipe and tubing ends sink into the ground very easily without my custom-machined ball joints and spreader plates.
-jsw
Oops, I misread my tabulation. The center load was 1000 lbs.
-jsw
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