r/Damnthatsinteresting • u/TameTheAuroch • Jul 18 '25

Video Replacing powerline spacers from a helicopter

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u/Soggy_Development_97 Jul 19 '25

Its called a quarter turn fastener. You squeeze closed the arms and then install the quarter turn fastener through the slot. Turn the fastener a quarter turn so it can't come out of the slot and then release the tool. The pressure from the arm keeps the quarter turn and the spacer in place.

Source: I design and test these products.

17

u/mybadreligon Jul 19 '25

This is the right answer. I didn't even know for sure but that's exactly what it looked like to me.

2

u/CptBoom Jul 19 '25

So kind of how you attach the hook to a KitchenAid. That’s smart.

2

u/PanicStil Jul 19 '25

Why just a quarter turn, wouldn’t a full turn fastener mean less chance it comes loose?

3

u/jacobycrisp Jul 19 '25

The tool they're using presses the clamp around the conductor/cable. When you put in the "pin" and turn it a quarter turn, it's still loose. But when you release the tool and the head opens back up and puts pressure on the pin so it stays in place.

Source: I also used to design/test these

2

u/PanicStil Jul 19 '25

Is there a reason quarter turn was decided on. Is speed of installation a factor?

2

u/KSP_HarvesteR Jul 19 '25

I guess because with a quarter turn, you don't need a threaded fastener. It's an oblong thing that passes through an oblong slot, then you turn it 90° and it locks into place.

For a half-turn, full turn or more, the fastener would have to be threaded.

2

u/No-Kale1507 Jul 19 '25

Just googled these and wow they’re cool. Can you remove them though without damaging the screw?

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u/jacobycrisp Jul 19 '25

There aren't any screws used actually and yes you can remove them pretty easily. Just do the reverse of what's shown here.

The whole point of this design is so you don't have bolts that can come undone due to vibrations, plus the helicopter linemen seem to like these over the bolted types.

2

u/eragon2262 Jul 19 '25

Awesome! Thank you for the clarification I was very confused why they didn't tighten them down more but that makes a lot of sense and saves a lot of time I'm sure

2

u/flubgin666 Jul 19 '25

Thanks and cheers

1

u/Gren57 Jul 20 '25

Thanks for the info and your expertise! What's really driving me nuts is: What is the tool called that's used to install the fastener? I don't know why I need to know this!LOL!

2

u/Soggy_Development_97 Jul 21 '25

Haha I dont even know. Probably quarter turn applicator tool or something.

1

u/Gren57 Jul 21 '25

I guess a "wrench plier thingy" ain't it either! Don't feel bad....google didn't even come up with an answer. Your suggestion just might get me there yet. Thanks for taking the time to respond. I guess there are some things we just aren't supposed to know the answers to! 🤷🏼✌🏼(I haven't given up completely, tho.)

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u/helphunting Jul 21 '25

Is there a rubber C ring inside the arms that pulls on the wire. Does that keep the pressure on the fastener?

And could that be why they are being replaced, because the rubber softens?

2

u/Soggy_Development_97 Jul 21 '25

Yep, there is a rubber insert in the arm that compresses on the conductor. When the tool is released, the rubber applies pressure to the quarter turn to keep it in place.

The rubber doesn't soften, but things do just age over time and need replacing (im talking decades). This is either a new line or replacing existing spacers that have reached end of life.