Hardware ideas

[MikeyDSlagle]

So while the near-wife puts the baby down for the night, I have to hide in the computer room. That usual means I end up playing Kerbal or browsing rocketry related sites. Tonight's poison is E-rigging.com. Window shopping all the pretty hardware.

Now a thought comes to mind:
Why do folks use quick links and not shackles? Looks to me like it would be practical if you had the room. But I see now that I look more, WLL for 1/4" quick link is 880lbs and 1/4" shackle is 1000 lbs. I guess extra weight and price isn't really worth the small gain. Unless their Breaking Load is measured different, then the shackle would be better methinks. I have read posts (other forum) where a guy claims to have load tested some 5/16" SS quick links from McMaster Carr and they took 15,700 lbs before his load tester quit on him. Seems high to me, but I don't really know. And he says the threads were still usable. Hmm.

But all that aside. Does a shackle tangle too much or are folks concerned that it will loosen itself? Or is that the shackle may set sideways and compromise it's strength? I always liked shackles for some reason, maybe it is the rigger in me. Construction rigger, not parachute rigger.

Another something I found were these pad eyes:

Pad Eyes

A little research and it looks like they have a WLL of 500 lbs. No worry of it backing out, should be able to slide a swivel on it if desired. Probably wouldn't work on the centering ring but don't see why something like this wouldn't work on bulkplate or A/V bay lid. Anyone tried using one before?

Mikey D

 

[Handeman]

I've never tried shackles, but i wouldn't in a rocket. The slightly higher load limit doesn't seem worth the higher chance of snagging and tangling some recovery part. The quick links are smooth and have no protrusions to catch on anything.

As for the Pad Eye. I like that idea, especially if you run your threaded rods holding the av-bay together through the holes you mount the pad eye with. I think that should help reduce weight some and remove much of the load from the av-bay lids.

The whole thing comes down to loads and reducing those. That usually means reducing ejection charge sizes, but since a lot of people seem to like the blow it out or blow it up school of ejection charges, you're back to load limits and sizes again.

 

[qquake2k]

It's funny you should mention shackles and E-Rigging. I just ordered a couple of small shackles from them to try. I thought about the catch on on protrusions possibility, but in my case I don't think it will be an issue. The eyebolt I'll be attaching the shackle to is pretty low profile. Anyway, I'll see. I too am a big fan of hardware, I love to play with it, and try new things.

 

[MikeyDSlagle]

Looks like we are thinking along the same lines.

I also looked at some heavier pad eyes that would work for larger rockets, something like 1000lb WLL.
https://www.e-rigging.com/pad-eye-diamond

This also got my attention, not sure how swivelly it is.
https://www.e-rigging.com/pad-eye-square-swivel
I may order a few to look at.

I ordered some shackles a while back but never fit them into a build. If kept close to the bulk plates the risk of tangling is reduced.

I'm always shopping for hardware to try something new. There is risk vs reward in just about every aspect of this hobby. Glad to see some folks think along the same lines as me.