Aircraft Cable; use of swages

[Edrick]

Well first off what's the correct term or is that it? We just purchased a 1000' spool of 3/16 cable along with the stops, ovals and the name that escapes me but the metal ring that the cable wraps around.

We're using it to string cabling from location to location for outdoor events along with some construction light stringers. So basic uses right now, I'm curious as to what advice people have with using the cable. I've watched training videos from Nicropress and read up on some other topics on here. Making sure to use the gauge to ensure the connectons are properly crimped.

 

[derekleffew]

Well first off what's the correct term or is that it? We just purchased a 1000' spool of 3/16 cable along with the stops, ovals and the name that escapes me but the metal ring that the cable wraps around.

Thimble. Yes, aircraft cable. Cable, aircraft, GAC, wire rope--all terms used pretty much interchangeably.

Some random points regarding swaging:

1. The order of crimps matters.
2. Hold each crimp for the manufacturer-recommended amount of time. [myth busted: see post#11 below]
3. Always use the Go/No-Go gauge.
4. When a swage is complete, the dead end of the cable should protrude from the sleeve at least a length equal to the cable's diameter. This is a somewhat controversial issue, as most want it to be even with the end to avoid "cable splinters." I say make the dead end longer, like 1", and e-tape or shrink tube the excess.

BTW, it's Nicopress, not Nicropress. Many want to add that extra "r". Be manufacturer agnostic and use "swage tool" instead.

 

[Edrick]

Hey Derek,

I was actually about to revise my post and mention those few points that I did find in my research. We make sure to purchase the matching stops or ovals for our tool. I was about to ask about the dead end in terms of how far it should protrude so that helps. As far as the order goes I was just reading a topic on here where it says that only matters if you're doing three crimps is that correct?

Also I'm curious as to the copper vs. aluminium I understand why not to us it but what is considered "rigging" compared to what you would use the aluminum ovals for? What applications are the aluminum acceptable

 

[jstroming]

I LOVE these end caps from McMaster. They are awesome for aircraft cable.

McMaster-Carr

(first item)

 

[gafftapegreenia]

Hey Derek,

I was actually about to revise my post and mention those few points that I did find in my research. We make sure to purchase the matching stops or ovals for our tool. I was about to ask about the dead end in terms of how far it should protrude so that helps. As far as the order goes I was just reading a topic on here where it says that only matters if you're doing three crimps is that correct

Different size sleeves and different manufacturers call for differing numbers of crimps. The "average" number is three, some larger cables use four, and if the tool is hydralic/not manual, it may only need one or two. The manufacturers instructions will tell you how many crimps are necessary.

 

[Edrick]

We're using 28-6-X with the NICOPRESS 63V-XPM SWAGE TOOL the tool didn't come with any chart and neither did the ovals, do you happen to know where i can get a PDF?

Actually found the diagram on the box and it tells you the order.

 

[derekleffew]

... As far as the order goes I was just reading a topic on here where it says that only matters if you're doing three crimps is that correct?

No.

... Also I'm curious as to the copper vs. aluminium I understand why not to us it but what is considered "rigging" compared to what you would use the aluminum ovals for? What applications are the aluminum acceptable

I'm not sure where the distrust/dislike of aluminum sleeves comes from--they're all I've ever used. When the leading stage rigging expert in the US says aluminum sleeves are perfectly acceptable in almost all cases (one exception: a corrosive environment, next to an ocean), I believe him.

http://www.controlbooth.com/forums/lighting-electrics/11934-safety-cables.html , posts 41 and 44.

 

[gafftapegreenia]

No.

I'm not sure where the distrust/dislike of aluminum sleeves comes from--they're all I've ever used. When the leading stage rigging expert in the US says aluminum sleeves are perfectly acceptable in almost all cases (one exception: a corrosive environment, next to an ocean), I believe him.

http://www.controlbooth.com/forums/lighting-electrics/11934-safety-cables.html , posts 41 and 44.

I heard straight from O. Glerum that aluminum sleeves fail far more often than copper sleeves in shock load tests. However, in pulling tests, both are about even.

 

[derekleffew]

From a 2005 post to the SML:

Preface: The name Nicopress has become the generic name for all sleeves.
It is inaccurate and confusing. Just like Crosby is the name of a company,
not the piece of hardware. The same is true for Nicopress. And just like
Crosby, I have found that people, when ordering Nicopress, are unwilling to
actually pay for Nicopress.

Depending on your definition of an Off Brand, it's entirely possible that
National Telephone IS the off brand.

The other company that makes Oval Swage Fittings is the Loos company out of
Naples Florida. While I don't have any hard data at my fingertips (it is
Sunday morning after all) I know that we sell at least 5 times as many Loos
sleeves as we do National Telephone. They cost considerably less.

Put the 2 brands of sleeves side by side on a table and you won't be able to
tell which is which.

The difference in failure rate between the 2 manufacturers is somewhere
around zero.

But there is a difference in size between the 2 companies whether you can
see it or not. If the sleeve, crimping tool and go/no-go gauge do not all
come from the same manufacturer, there is a possibility of getting an
inaccurate reading from the gauge.

And there is a difference in installation requirements. On the sizes we are
most likely to use, the National Telephone people require 3 crimps. On the
same size sleeves the Loos company requires 4.

The difference between copper and aluminum? Age old debate.

Failure rate difference due to material or manufacturers defects.
Negligible.

Failure rate difference due to improper installation. Negligible...Humans
screw up copper or aluminum sleeves pretty much the same.

Material difference....a little. Copper is harder. Aluminum may not
withstand the test of time as there may be some corrosion between the
aluminum and the galvanized steel. But I'm told that the process will take
about 75 years, so I'm not too worried about it (I won't be here)

Shock loading...I'm told that aluminum may crack more easily under a shock
load. Might be true BUT...both manufacturers recommend that both styles of
sleeve be replaced after a shock load has been applied.

So......The common practice in the industry right now is to use copper. Or
zinc coated copper (copper oxidizes, after all) OK. I'll sell you copper.
or zinc coated copper. Or, when someone finds a problem with zinc and they
decide that a platinum coating over the zinc coating on the copper sleeve is
the way to go, then I'll sell you that one too.

 

[MNicolai]

I heard straight from O. Glerum that aluminum sleeves fail far more often than copper sleeves in shock load tests. However, in pulling tests, both are about even.

That's what I've been told, that copper sustains a shock load better than aluminum will. Whether there's truth in that or not, the cost difference between copper and aluminum sleeves is negligible for the diameter of wire rope that I work with frequently, so I've never had a reason not to use copper.

 

[MPowers]

Another name that architects and engineers are using is Small Diameter Specialty Cord.

Order of crimps. Not critical as long as you never make a crimp between two other crimps. Work from the middle out or one end to the other, but never start on the outside and finish in the middle. Measure the overall length of your sleeve before and after crimping, there is a considerable amount of elongation. Making a crimp between two others will either stretch the GAC or force it to slip a little in one or both of the other crimps. My personal preference is, counting the crimp closest to the thimble as #1, to do a 2 crimp 1-2, a 3 crimp 213 or 123, a 4 crimp 2134 .

Hold time: Myth. If you completely close a manual tool or hit the stop on a powered tool and the crimp fits the proper gauge, you are good to go.

Thimble. Remember, the thimble should be slightly loose when the crimping is complete, NOT tight. Not loose enough to come out the the loop but enough that you can wiggle it. This allows the load and the thimble to self center as tension is applied.

Aluminum: In a recent conversation with a Nicopress engineer while discussing stainless steel vs plated copper for permanent, over head lifting, installations in outdoor exposure conditions, it came up that Nicopress does not endorse, recommend or approve of the use of aluminum sleeves for overhead lifting. We didn't discuss why. Aluminum is acceptable for farm use, fencing, crowd control barriers, and the like. I simply will not use it for any over head lifting or suspending. I don't care if the connection will last 75 years without corroding, I don't want my legacy 76 years from now to be that I installed the rigging that failed and inured or killed someone. To steal a phrase form Unka Bill, I stand behind AND under my rigging.

When the leading stage rigging expert in the US says aluminum sleeves are perfectly acceptable in almost all cases (one exception: a corrosive environment, next to an ocean), I believe him.

Who is this expert? I read the posts cited and I don't see this declaration. Nor is the "expert" mentioned in the posts. If I missed it please let me know.

Exposed dead end length. During the afore mentioned conversation with the Nicopress engineer, I asked about this and was told that the reason for extending the cable was that if the end crimp was too close to the end of the cable, it deformed the strands (notice the way they spay when you crimp too close) and compromised the strength of that crimp. The CLE method of finishing the end is to extend the dead end 1/2" to 5/8", bind the dead end as close as possible to the working line with E-tape and then heat shrink the connection with 1 1/8" section of heat shrink tube flush to the sleeve on one end.

 

[derekleffew]

...Order of crimps. Not critical as long as you never make a crimp between two other crimps. Work from the middle out or one end to the other, but never start on the outside and finish in the middle. Measure the overall length of your sleeve before and after crimping, there is a considerable amount of elongation. Making a crimp between two others will either stretch the GAC or force it to slip a little in one or both of the other crimps. My personal preference is, counting the crimp closest to the thimble as #1, to do a 2 crimp 1-2, a 3 crimp 213 or 123, a 4 crimp 2134 . ...

That reminds me: IF making crimps in 1234 order, one can end up with a curved, or banana-shaped, sleeve. While not structurally deficient, it's unattractive. Reverse the tool, or the sleeve in the tool, every other crimp to counteract the bending.

 

[MPowers]

....IF making crimps in 1234 order, one can end up with a curved, or banana-shaped, sleeve. While not structurally deficient, it's unattractive. Reverse the tool, or the sleeve in the tool, every other crimp to counteract the bending.

What Derek said! Especially true when using manual crimp tools.

 

[MarshallPope]

Slightly off topic, but what is the correct pronunciation of "swage?" I have heard multiple things, and have always wondered which was correct.

Thanks

 

[rochem]

When crimping, just remember - like in many applications, more is not always better!!



(Photo from JR Clancy)

 

[len]

http://www.jrclancy.com/Downloads/Nicopress.mov

I didn't know there were videos on their site. All the cables I made for hanging paper lanterns, etc., are probably made incorrectly.

As for the 75 year thing, not a worry for me. None of the stuff I hang stays up for more than a day or two, and there's no way I'll be in this business in 75 years.

 

[derekleffew]

Slightly off topic, but what is the correct pronunciation of "swage?" I have heard multiple things, and have always wondered which was correct.

Thanks

Long "a." swage - definition of swage by the Free Online Dictionary, Thesaurus and Encyclopedia. , click on the speaker icon.

 

[MNicolai]

Another name that architects and engineers are using is Small Diameter Specialty Cord.

Order of crimps. Not critical as long as you never make a crimp between two other crimps. Work from the middle out or one end to the other, but never start on the outside and finish in the middle. Measure the overall length of your sleeve before and after crimping, there is a considerable amount of elongation. Making a crimp between two others will either stretch the GAC or force it to slip a little in one or both of the other crimps. My personal preference is, counting the crimp closest to the thimble as #1, to do a 2 crimp 1-2, a 3 crimp 213 or 123, a 4 crimp 2134 .

Anyone notice before that the Backstage Handbook has a diagram showing improper crimp order?

 

[rochem]

Anyone notice before that the Backstage Handbook has a diagram showing improper crimp order?

Yup. Sadly, that's just one of the down sides of having a quick-reference guide that hasn't been updated in 20 years.

 

[tprewitt]

Another name that architects and engineers are using is Small Diameter Specialty Cord.

The CLE method of finishing the end is to extend the dead end 1/2" to 5/8", bind the dead end as close as possible to the working line with E-tape and then heat shrink the connection with 1 1/8" section of heat shrink tube flush to the sleeve on one end.

I seldom disagreed with anything MPowers posts but I'd have some reservations with this practice. In destructive testing, unless there is a defect in the wire rope, it fails at the top of the compression fitting. Most times a few strands will break flush with the fitting, the cable will elongate a little, then it all comes apart. For this reason I always make sure the area of the cable right above the fitting is visually unobstructed so it can be easily inspected. I recommend to stage hands to make a habit of looking at this spot anytime a fitting is in front of them. I really like the look of the heat shrink but I'd probably leave 3/8" - 1/2" gap for inspection.

For 1/4 & 3/16 cable our method is:
1) Leave 1 cable diameter protruding from the uncompressed sleeve
2) Compress to 9300 PSI (We mostly use an electric pumps on #435 tools)
3) For Hand Tools, 3 crimps starting at the thimble end, middle, then dead end.
4) At the beginning of every a work shift, we mic a test compression to verify proper diameter & length. (We worry constant use of a go-no go gauge will wear the gauge & dies simultaneously. Not applicable to most, just occasionally check your gauge!)
5) Inspect
a)When compressed the dead end should extend "any measurable distance" from the sleeve. (typical is about 1/16" - 1/8" depending on how well you did in step 1. "Any measurable distance" is direct from National Telephone. They explained this is sometimes confusing so they also give guides such as X inches or 1/2 cable diameter, but "any measurable distance" is all that is required.)
b) Sleeve should be straight with no marring (caused by dirty or damaged dies.)
c) No overlapping or crooked crimps, no crimps that extend over the edge of the sleeve (Hand tools)
At the end of the project, we go back and dab a tiny dot of thick epoxy on the raw ends of the cable and with a verified go-no go gauge check compression diameters.

We use Nicopress (c) fittings and tools exclusively. Not because they are better or safer than Loos, but because we want to use tools & fittings from 1 manufacturer and we like the #435 tool. We only use copper (aka Nickle-Coper, hence NiCo). The plated ones are fine, but I don't install many rigging systems in highly corrosive environments so there's no reason to use them. Logic and experience, not documented proof, indicate aluminum may provide lessor performance. While I don't see an issue using aluminum in dead hangs (look at the fittings on high voltage power lines) I wouldn't use them in our shop because we like consistency and the few cents savings is inadequate motivation to create a new complexity to our procedure.

Another persons procedure can be very different, and still be correct. Crimping from dead end to thimble or go-no go gauging every crimp, etc isn't wrong. What's important is there is 1 well defined, documented, procedure everyone on the site follows. This yields consistency which yields predictability. Predictability is the ultimate goal.