r/Rigging

Hello! New to the sub, but this seems like the best place to get answers from real experience.

I build cable at work reasonably regularly, but always using galvanized cable and copper sleeves. We only have manual swagers, but we're working on 1/16" to 1/4" cable, and the 1/4" is only rarely. I'm very comfortable working within those limits, but I have a special project that I would LIKE to do with stainless cable and stainless sleeves.

I was under the impression that stainless sleeves couldn't be swaged with the simple mechanical tools, only with hydraulic or electric ones, as mere flesh is too weak. But Nicopress explicitly lists hand tools for every size of stainless sleeve. I'm hoping to work in 3/16", but I could come down a bit if it lets me actually do the project with the tools available. 🤷

So my question is: is this really feasible? If I try to swage 5/32" stainless with a 51-M-850, it's it going to require Herculean strength or damage the tool, or is it a plausible thing?

Thanks for any insights you can give me!

Making this because it's difficult to find a comprehensive guide online.

This PDF is from "Backstage Handbook: An Illustrated Almanac of Technical Information" by Paul Douglas Carter

Hi everyone,

I'm a biomedical engineering senior working on my capstone project, and my team is designing a **mechanical pediatric knee extension brace** for treating post-operative knee flexion contractures after ACL reconstruction.

The device uses:

* BOA dial for adjustment
* Stainless steel cable (currently 1/16")
* Medial and lateral cable routing
* Side hinges
* No motors or actuators (purely mechanical)

The goal is to apply a **low-load, prolonged stretch** to gradually improve knee extension while keeping the force balanced to avoid twisting the knee.

Our biggest issue is that **tightening the BOA increases cable tension, but it doesn't actually generate enough knee extension.** It mostly seems to tighten the brace rather than rotate the calf into extension.

We've already considered:

* Different cable routing paths
* Larger cable guides/pulleys
* Moving the cable attachment farther from the hinge to increase the moment arm
* A floating bridge over the knee
* Static-progressive concepts similar to the Mackie Knee Brace

However, we're limited because we're near the end of the project and **can't completely redesign the device architecture (literally due in 2 weeks)** . We need to stay with:

* BOA dial
* Cable-driven system
* Side hinges
* Medial/lateral cable routing

My questions are:

1. How would you route the cables so tightening the BOA actually creates an extension moment instead of just compressing the brace?
2. Would adding pulleys or changing the cable angle help, or would that mostly increase friction and cable travel?
3. If you've designed cable-driven mechanisms before (orthotics, prosthetics, robotics, bicycle systems, etc.), what would you do differently?
4. Is there a cable routing strategy we're overlooking that can convert cable tension into hinge rotation without changing the entire design?

Any sketches, examples, patents, or similar mechanisms would be incredibly helpful. Even rough hand sketches or CAD screenshots would be appreciated.

Thanks!

Good morning. I am an Overhead Crane Inspector at TRHON. I'd like to share this experience from a few years ago and get your opinion on it.

At a gas-fired power plant, on a new 25-ton overhead crane (the plant wasn't operational yet), a non-destructive testing was performed on the hook of the main trolley using dye penetrant testing.

The first indication that something was wrong was that the entire hook was painted. We proceeded to remove the paint, which took a considerable amount of time. We then discovered grinder marks on the hook. The marks weren't from leveling bumps; they were quite deep.

The dye penetrant was applied, and the result was that the hook had no cracks, so it could be certified. However, due to the grinder marks, I refused certification unless the hook manufacturer had issued documentation detailing the grinding marks and the reason for them. If such documentation existed, with the manufacturer's endorsement approving this anomaly, then I would proceed with certification.

The hook documentation did exist, but it didn't mention the marks, so I refused certification, which caused a major conflict with my client, who initially refused to pay for the service.

The client (a German company) initiated a traceability investigation with the overhead crane manufacturer (a Finnish company), which revealed that the hook left the factory in perfect condition. The problem lay with the company that assembled the equipment.

This was all resolved with a load test conducted by the client, which resulted in the hook being approved.

All of this resulted in a delay of more than eight months in payment for my services. My initial decision was to reject the hook due to anomalies that lacked justification and explanation. The client insisted that these anomalies appeared minor and wouldn't affect the equipment.

In the end, they issued a partial certificate only for the penetrant testing, contingent upon subsequent certification through a load test. What are your thoughts on this?

Hey guys

I got a job offer at Mona's for intermediate rigger and I have a VOC to pass with them. Im pretty rusty from my ticket courses and I have virtualy no experience

Anyone has ever done the voc for intermediate rigger at Mona's in Perth and could tell me about it and/or tell me what I should get ready for?

Thanks