Double Cable Swaging - Risky technique

[Greg Mitchell]

Ditto Pete,Are we not always talking about dual type systems in case of failure. I know the double swagge does not look as good as a single but I agree whole heartedly with your Ultralight TA/instructor and a 3/8" gap is good. I used Nicopress swaggess and doubled and when I trashed my gyro all cables and end fittings remained intact.Mitch.www.thebutterflyllc.comA thinker sees his own actions as experiments and questions--as attempts to find out something. Success and failure are for him answers above all. - Friedrich Nietzsche

[asra]

As a matter of interst do they double swage on Pitts or Auster etc cables ?Aussie Paul.[]www.firebirdgyros.com

[asra]

Correctly swaged, the swage will not fail, the cable will part first and at the point where the cable exits the swage, normally caused by "whipping", Yacht side stays for example, even having owned my own yacht and knowing the strength and principles of swaging, when it came to Gyro's I still doubled swaged to get that "warm fuzzy" feeling, like John, I also ran a cord with the wire and tied them together, later using cable ties at approx one foot intervals to cover the cable parting at the front.Pete Barsden

[asra]

The only thing the second swage can add for anyone is extra wieght.Daryl Patterson

[NiqueNaque]

dARYL,I double swage for that 'warm fuzzy feeling' as Pete puts it.And who knows when they have stuffed up a swage?, two of them halves your chances of having done something wrong that will create a problem.Regards,Nick.

[mrford61]

Wouldnt there be something like "a chain being only as strong as the weakest link" thing happening with more than one swage? The second one may be undermining the perfectly good first one.If its slippage that is a concern why not put the second one on the tail end of the cable (one strand). As far as breaking goes multiples doesnt make any sense to me at all.* If I have over looked something really obvious go easy on me *MC

[NiqueNaque]

Mark,Not so, it is a complimentary situation, not one of detraction. I agree that a chain will break at the weakest link, but with swages the weak link may be the application, so put two on and the risk is halved, theoretically anyway.Its a bit like the accident scenario with swiss cheese, all the holes have to line up for an accident to get through the loop holes and happen, two swages is another layer of cheese.Cheers,Nick.

[Brian]

All I will say here is that if Rosco put two swages on my cables, then I would be very worried !!Brian

[NiqueNaque]

Hey Brian,Its roasting up here .. how's the air con holding out?Cheers,Nick.

[mrford61]

But if either one breaks or causes a break the cable is in two halves.If you put a second swage on the tail only, say half inch from the first or closer if you want, it will only slip to the first swage. Negates the slip worry and it won,t comprimise the first swage in any way.?????? MC

[asra]

Understanding the principle of swaging and using the correct equipment gives the understanding of why swages dont slip, direct pull on cables can be rated in tonnes.Pete Barsden

[asra]

What pete said I have worked with lifting slings [cable] & they lift 5-10 tons only one swageButch.ps Merry Xmas to all

[asra]

OK........this is where I come in. Being now a semi retired commercial fisherman I've had a bit to do with swages.Right swage,[just the one needed ] to suit the particular cable, using the right tool, operating that tool correctly, will guarantee no problems ever. If the cable is overstressed [ overloaded ] the cable will BREAK.........the joint will not let go........guaranteed.

[asra]

You are right Paul B, Pitts specials and others have double swages,but only copper ones from what Ive seen. Frilly is 100% right IMHO, One stainless swage is all you need. I used to get mine done at a boat shop that used a hydraulic press to fit them.I now use the "Bolt cutter" type tool and the force on this at the jaws would be a couple of ton. The swage tools you see that fit into a vice and get done up just with vice preasure I would be very cautious about.

[asra]

Frankly I'd prefer to gety my "warm fuzzy feelings" from proof loading. Who can say whether two poorly done swages offer better safety than one done properly?If you'd loaded the thing to cope with the specified loads multiplied by the specified safety factor anything additional is just superstition IMHO.Wouldn't it be more rational to run two separate cables?I'm not sure, but I think the Tiger Moth does that for elevator.John EvansThink logically and do things well, think laterally and do things better.