I have first hand refute of this assertion (though it was a cheapo set, but then I was half the man back then, too)…
Based on what everyone here has said (and if I’m doing the math correctly) the frame should be able to support the 500 lbs. But after @carpa said about safety factors, I’m thinking about upsizing from 1" to 1.5" square tubing (have to stay at 14 ga though) that should give me a saftey factor of about 2 for my estimated 500 lb load. Although now @HankCowdog has me worried about the corners. Will the weld be able to support the cabling or should I add a bracing of some sort? Should I just add a basic gusset anyway?
I would bolt the cable eye to the frame. It is more predictable for calculating failure. Also, if you weld rated hardware, it loses any rating because they achieve that rating through heat treatment.
that was the plan: drill a hole through the little bits that stick out from the ends and run an eye bolt through there
I was more wondering i the welds holding the bars together would be enough. I know that they’re supposed to be stronger than the parent metal, but for some reason that always seemed kinda dodgy to me
The real problem is the heat affected zone immediately adjacent to the weld. I would use tack welds and plan for the long members to carry the load. Figure the cross braces just serve to prevent the longest members from rolling/spreading. The less time you maintain a bead, the less likely you are to make the HAZ brittle.
but also more expensive and and i have to keep the client’s budget in mind
and where can i find eye bolts rated for 625 lbs?
These eye nuts from Grainger are rated to 2700 and are 3/8"-16 threaded. They have forged eye bolts too, if you prefer, but it is easier to find standard bolts in the length you need than eye bolts.
Those are great. Now I need to find an equivalently rated bolt with equivalent rating. Also, the cost is an issue, since the client is working on a budget. Just the nuts will be almost $50. And from what I can see of the bolts that even more cost right there
To rip a bolt through the metal will take a lot force. If you want to make much stronger, fit a sleeve between the two walls so it is in contact on the inside. Have it so there is a nut and washer on each side that when tightened compress the sleeve slightly. That now transfer some of the load to the top wall and reduce the ability to tear through. This reduces the ability of the single wall on the bottom to deform leading to outer walls from buckling.
The sleeve forces both walls to deform at once and you get the benefit both vs one.
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Standard Grade 8 bolt should be more than enough.
would black iron pipe work for the sleeve?
Four Grade 8 Bolts? These are rated up to 150,000 psi. I’m guessing you’ll be using 3/8ths bolts, maybe bigger. Their cross section = .11 sq inches, 4 of them equals .44 sq. inches or 60,000+ psi tensile strength. You are spending way to much for hardware. A grade 3 would do fine - if worried, bump the diameter 1/8th inch. The frame will bend and ceiling collapse before the bolt snaps.
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I stand corrected. I defer to someone with more welding knowledge than myself.
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Actually, on that note, does anyone know when the next MIG welding class is?
someday we will also have holodecks too LOL
also, the calendar has none scheduled
HAZ issues typically only comes into effect on say Chromoly, or other heat sensitive alloys. Chromo while welding you want to keep the zone as narrow as possible, then heat treat the part.
Personally I would do a square weld washer on the bottom side & sleeve it at the eyes. 1/8” would be fine but I’d go with about 3/16. I would then weld triangulated gussets or tube on each load corner as a bare minimum.
Search 3/8 eye bolts & you will find a slough of them to choose from, I’d go with something with a known published rating.
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Gusset gusset gusset!
I’m currently going with these ones rated for 380 lbs
https://www.homedepot.com/p/National-Hardware-1-2-in-x-4-in-Zinc-Plated-Eye-Bolt-with-Hex-Nut-2160BC-1-2X4-EYE-BLT-ZN/2045889311