Well that was quick. An early morning run to Home Depot, a couple hours with the circular saw and drill, and a LOT of sweat.
Just sitting on the grass, this is a bit tippy. It will need some sandbags placed on the feet to keep the gantry from tipping over. I had a swing-set of roughly the same design as a kid, but those legs were put into concrete in holes. A long 2x4 screwed to the bottom of the gantry would work too.
It took two people and some very awkward rope work to flip Goat and pull it up most of the way to the beam. Next time I will remove the wheel to have another half-foot.
The toughest part now is how to secure the structure to the overhead beam. I have that yellow strap looped over the beam and looped around the wing carry-through tube, but can't quite get the water knot tied. There's a foot overlap, but another foot from removing the wheel would make it workable. How to get the structure all the way up there and tie it may be a trick. A friend suggested taking one end of the gantry off and lifting it up after tying the knot. It may also work to tip the gantry over sideways. It'll be easier with more people.
I want to space those pick-points as wide as possible so it is closer to the ends of the tube instead of near the middle. The wheel trusses will help transfer the load around if picking from the middle. Just a lot of bending on that tube...
While it was up, here's how I intend to hang weight. Each of those gallon jugs is 8lb of water. Looping the string once around the spar provides some friction, and actually looping it over the rib attachment would be smart too. I'll need to do the math for splitting up the load into rib-spacing increments.
Since there will be so much riding on this test, I will also do a proof loading of the gantry. 3.5G plus the roughly half-G of weight is 350lb*3.5 + 100lb is 1325lb. Splitting into 8lb increments is 165 milk jugs. Woof, that's a lot of jugs.
The weather Sunday is supposed to be gorgeous! Load testing party at my place on Sunday :-)
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