It's an oddball size, so cutting the parts out of a piece of existing channel was out of the question. There can be some kind of adaptation later on, with some thought, I imagine.
Here is the subject. A water blasting crawler that scales the sides of ships, held on by suction.
Which needs a roll cage. The use of aluminum is entirely experimental as these parts were made of SS prior. To hand cut and drill 1/4" SS flat bar on short notice, or to economically have them cut elsewhere for so few parts was the deciding factor as was the schedule.
Instead of using one, 1/4" stainless steelplate for the sling eyes, it has two 3/8 aluminum that does away with the clevices they currently use. Just a bolt or pin thru a cable eye instead.
The pipe is double wall sched forties making an 80. A 3/4", 6061-O inner, with a 1", 5052 outer. The 5052 takes a puddle quicker and welds faster and in theory, keeps heat stress/brittleness to a minimum. You can use those 'fudgy', fat aluminum welds on this material that end up being rather tough, without creating a fracture zone right at the edge of the weld and without undercut or overlap. The two wall, sched 80 buildup also helps alleviate this, over that of a single wall 80 construct. Is it overkill or in vain? Perhaps. . .but all we can do is try and guess when time is of essence.
At any rate, I made the deadline and used almost to the inch, what material we had readily available.
