AC 43.13 1B section 7-148 to 7-153 ppgs 7-30 to 7-39 is the accepted practice & approved methods of swagged cables for aircraft. A home builder should read and understand how to use the swagging tools and practice on a few before actually making a control cable for an aircraft. It's not difficult once you get the hang of it. This illustrates that one mechanic improvised a way, adapted it so he or she could work alone, and overcame the difficulty of needing a second set of hands to help accomplish the same thing. This A & P Mechanic is learning new tricks to make his day go smoother. Enjoyed the video, thanks for posting.
As a teenager I worked in a rigging shop and was taught by the original swage fitting manufacturer how to do these. They would suggest that the technique shown here is NOT good. They always taught to size your cable the right length so that its cut end is flush with the swage fitting. The original swage mfg. did not suggest that the cable exits the swage fitting as it leaves cable that can only become a "gotcha". Start swaging from the end farthest from the thimble first. As you move towards the thimble, the swage grows in length and makes a tight termination. Also, there is no need for two swage fittings as you seem done sometimes - it is actually weaker.
TalonID... Hi, it's always interesting to hear from someone who's worked in the field being discussed. I can see the sense in not having a long tail sticking out beyond the swage... it's a definite snagger and "gotcha" as you mentioned.. but putting two swages on the thing is an understandable 'belt & braces attempt by many people I think. I've done it myself, although not in this aeroplane sense. I'm certainly willing to take your word that putting two swages on weakens the whole thing, but I'm just not sure why this could be.. Any crushing by the extra swage wouldn't effect the diameter of the wires in the first swage would it? Maybe if it was butted up really close I guess.. but if a 'swage length gap', say, was between them, the wires would be still at the original diameter wouldn't they? Or is there some other reason? Just thinking out loud here, not a criticism.
Nicopress tested two swages vs. one, the single always broke at a higher load. Not sure why but testing tells the truth. It is important that the swages are completely crimped. Don't be lazy and stop short. BTW - I really like your videos!
The swage fitting manufacturer is a telephone company. Not that telephone cables can’t present dangers but they are in an entirely different league than flight controls. They did not go through the battery of engineering tests that aircraft manufacturers and regulators did when they appropriated these parts and tools for aviation. AC43.13... which is an FAA Advisory Circular which governs the acceptable practices on aircraft that aren’t explicitly detailed in an Airframe Maintenance manual has a very specific process for this. The sleeve is placed a small distance from the thimble to allow for expansion. Then-very specifically, the centre of the sleeve is squeezed, then the part of the sleeve closest to the thimble (which will now close the gap), and then the part of the sleeve furthest away. Always in that order on aircraft. Then you use a no-go gauge to confirm it has the right compression. For a cable splice using nicropress sleeves... it says in AC43.13 very specifically that you need to use two sleeves to perform a splice, and when you use two sleeves and they are properly pressed the cable strength is 100% of the original cable.... as opposed to 75% for a woven splice. As for extra cable being a “gotcha”. Please. You need to have cable going all the way through the sleeve for the required strength. Cable is often cut in rough lengths and swaged in situ. The end can easily be trimmed with a cutoff wheel using a thin piece of stainless steel to protect the other cable. Alternatively, you can use a piece of shrink wrap to contain any loose or sharp ends.
Awesome tip. At first I was like... the vice is usually where I put the nicropress... (so I can have two hands free to keep everything in place on the cable before I press it) but I think this is a better use of the vice. Thanks!
back off the adjustment on the crimper to get the first press and hold things in place, then go back and do it again at the final setting grab the cable and sleve with a rag in your hand, then you can really push it up against the thimble. you can hold things in place with a regular cable clamp too, just gently tighten it, you don't need much, it leaves no damage to the cable
Thank you for sharing this. The Cleco pliers are perfect for this application. I would like to respectfully mention some facts about plated copper Nicopress sleeves. Nicopress sleeves are designed for Flexible cable. Not strand (1x19, 1x7 etc). They will work with strand, but a copper sleeve is designed for 7x19 (shown), 6x19 and its variations like IWRC, or even 6x7 or 7x7. They are manufactured by and are a trademark of the National Telephone Supply Company. There are many other manufacturers of oval sleeves as well. They are for Flexible Wire Rope, not electrical wire. Not "telephone" wire. GAC? Yes. There are other types of Nicopress sleeves too: Round stop sleeves, aluminum oval sleeves for fibre rope etc. These are Oval Sleeves. For Flexible Cable you can use plain copper sleeves or preferably plated copper sleeves. I am calling the size in the example 5/32". It is hard to eyeball something in a video, but if it were 3/16", the sleeve would be noticeably longer in length, relative to its width. If it were 1/8", it would be tiny compared to the size shown. This sleeve will expand in length 5/32" after being pressed 3 times with an M die. This is the rule of thumb for all Nicopress sleeves: they expand the same amount as the cable diameter after pressing is finished. There will always be one die designation in any application that is most popular, like the M die I mentioned, but there are often other size dies that will work as well. They will always have a maximum finished sleeve make-or-break diameter, and a specific number of presses required by specific dies. Using an M die, this sleeve gets 3 crimps. Sometimes the same die will work with different diameters. 3/16" and 7/32" cables use size - specific sleeves but they can both be crimped with an "X" die. According to the manufacturer's instructions, which are the same as the instructions from Universal Wire Rope and other manufacturers btw (some out of business), the cable end Must protrude from the sleeve after pressing is finished, a minimum of "One cable diameter" if you expect 100% strength. So if the sleeve is going to expand 5/32", and we want 5/32" sticking out after pressing, then you will need to start with 5/16" sticking out. Except: if you start pressing at the middle of the sleeve, then the sleeve will expand towards the thimble when you do the crimp next to the thimble. The finished sleeve should not touch the thimble. I aim for 1/2 of the cable diameter = the space between the thimble points and the finished sleeve. If, after swaging, the thimble is jammed against the sleeve, or causing the thimble to angle-off, then that swage should be rejected. In my line of work, we don't care if the swage is absolutely 100%, and so we try to end up with the cable end flush. This is so that people handling the cable don't get poked or injured by the protruding end. Cutting the excess cable off flush with a grinder/cutoff wheel is not recommended- it is too easy to nick the working part of the cable. Just the slightest scratch from an abrasive wheel will absolutely ruin the eye. How will the inspector know if the cable is injured or nicked if there is heat shrink covering the swage? Heat shrink makes the swage look better, but I would not use it for flight controls. I guess this is obvious to many people, but I have seen it done wrong countless times; the sleeve is oval shaped in section. That's why they're called oval sleeves. The sleeve must nestle in the circular groove of the die. Close the die around the sleeve, and before applying any pressure, do your final adjustment. Then close the die. I cannot tell you how many times i have seen sleeves crimped sideways, or detented by the tip of the tool instead of enclosed by the circular die. It helps to have one arm of the swaging tool in a vise, holding the tool stationary. I intend to not use my cleco tool in the vise, but to let the vise hold my Nicopress tool instead. If you wish to swage the middle of the sleeve first, that's fine. Just leave enough room for expansion between the thimble and the oval sleeve. Does that mean that the middle crimp should be exactly in the middle? If it is a hair short of the middle - a bit farther from the thimble - then the squeeze next to the thimble can be a bit farther from the thimble as well. This will make a nicer "bell-mouth" at the throat of the eye. Always complete your crimps with One closing of the tool, not repetitive crimps in the same spot. If it doesn't measure in, adjust the tool using the manufacturer's instructions. Never turn any screw or bolt on a closed tool. Always open the tool first. Keep your swaging tool lubricated. I use Triflow. I personally always rotate the sleeve 180 degrees relative to the press I just did, adjacent to the press I'm doing next. The crimps on the sleeve should never overlap. There should always be a ridge of flashing between presses. The crimp should never be flush with the ends of the sleeve. I do not believe that two sleeves crimped in series are stronger. I have never seen any manufacturer recommend this for creating loops. But I have used a second sleeve to cover the sharp cable end many times. When I do that, I do (a) very light partial crimp(s) on the second sleeve covering the sharp cable end. There must be adequate distance between the two sleeves, I use 1-1/2 pics of the cable lay (you could say the pitch of an individual strand + 50%). If two sleeves are used in the name of strength, it is an illusion. If they are too close together, there is a hard spot created between the sleeves which will destroy the integrity of the swage. If two sleeves are used and the order of pressing is such that the presses are converging towards each other, it will create an imbalance which will also destroy the integrity of the splice. Sometimes I put a blob of non-silicone adhesive caulk (like Sudbury Elastomeric Sealant) or maybe some Loctite GoTo Glue, on the exposed cable end, to prevent people from getting poked by the sharp cable end. Tip: Start by making a ring around the cable with a sharpie, 18" from the bare end. Make your swage loop. Then measure to the sharpie ring again, and subtract that number from 18. That is how much cable you will need to add to the other end before cutting in order to hit your correct finished cable length. Measurements are made to the inside bottom of the loop when referring to the finished length. One rule we live by is never cut any cable until you absolutely have to. Always start with way more extra than you think you'll need. Then you can reject the first attempt without ruining the whole thing. Always cut aircraft cable with cable shears designed for cutting flexible steel cable. Bolt cutters, dikes, and electrical cable cutting shears are not appropriate. If you want to use a wheel to cut your cable, OK. I use cutoff wheels on cable over 1/2" dia all the time. But it will leave the cable in an unbalanced condition. Make sure the strands are not fused together. Using a cutoff wheel or torch to cut cable is not recommended.
That is a method for "soft" eyes, not thimble eyes. Forming a Flemish eye in the cable before inserting the thimble will make an eye that is too large for the thimble. Yes, it's a better loop, but not practical with thimbles.
AC 43.13 1B section 7-148 to 7-153 ppgs 7-30 to 7-39 is the accepted practice & approved methods of swagged cables for aircraft. A home builder should read and understand how to use the swagging tools and practice on a few before actually making a control cable for an aircraft. It's not difficult once you get the hang of it. This illustrates that one mechanic improvised a way, adapted it so he or she could work alone, and overcame the difficulty of needing a second set of hands to help accomplish the same thing. This A & P Mechanic is learning new tricks to make his day go smoother.
Enjoyed the video, thanks for posting.
It's actually AC 43.13
duly noted and edited. Posted this after a long day in the hangar- work shop.... nice to see someone is paying attention.
Godfrey Poon We are up to revision AC43-13 2B. You’re living in the past, get with it.
1B and 2B are different parts and are both current.
It would have been nice to see the the job finished off and thefinal product displaid, but helpful all the same. Thank you.
As a teenager I worked in a rigging shop and was taught by the original swage fitting manufacturer how to do these. They would suggest that the technique shown here is NOT good. They always taught to size your cable the right length so that its cut end is flush with the swage fitting. The original swage mfg. did not suggest that the cable exits the swage fitting as it leaves cable that can only become a "gotcha". Start swaging from the end farthest from the thimble first. As you move towards the thimble, the swage grows in length and makes a tight termination. Also, there is no need for two swage fittings as you seem done sometimes - it is actually weaker.
TalonID... Hi, it's always interesting to hear from someone who's worked in the field being discussed.
I can see the sense in not having a long tail sticking out beyond the swage... it's a definite snagger and "gotcha" as you mentioned.. but putting two swages on the thing is an understandable 'belt & braces attempt by many people I think.
I've done it myself, although not in this aeroplane sense.
I'm certainly willing to take your word that putting two swages on weakens the whole thing, but I'm just not sure why this could be.. Any crushing by the extra swage wouldn't effect the diameter of the wires in the first swage would it?
Maybe if it was butted up really close I guess.. but if a 'swage length gap', say, was between them, the wires would be still at the original diameter wouldn't they?
Or is there some other reason?
Just thinking out loud here, not a criticism.
Nicopress tested two swages vs. one, the single always broke at a higher load. Not sure why but testing tells the truth. It is important that the swages are completely crimped. Don't be lazy and stop short. BTW - I really like your videos!
The swage fitting manufacturer is a telephone company. Not that telephone cables can’t present dangers but they are in an entirely different league than flight controls. They did not go through the battery of engineering tests that aircraft manufacturers and regulators did when they appropriated these parts and tools for aviation.
AC43.13... which is an FAA Advisory Circular which governs the acceptable practices on aircraft that aren’t explicitly detailed in an Airframe Maintenance manual has a very specific process for this. The sleeve is placed a small distance from the thimble to allow for expansion. Then-very specifically, the centre of the sleeve is squeezed, then the part of the sleeve closest to the thimble (which will now close the gap), and then the part of the sleeve furthest away. Always in that order on aircraft. Then you use a no-go gauge to confirm it has the right compression.
For a cable splice using nicropress sleeves... it says in AC43.13 very specifically that you need to use two sleeves to perform a splice, and when you use two sleeves and they are properly pressed the cable strength is 100% of the original cable.... as opposed to 75% for a woven splice.
As for extra cable being a “gotcha”. Please. You need to have cable going all the way through the sleeve for the required strength. Cable is often cut in rough lengths and swaged in situ. The end can easily be trimmed with a cutoff wheel using a thin piece of stainless steel to protect the other cable. Alternatively, you can use a piece of shrink wrap to contain any loose or sharp ends.
Awesome tip.
At first I was like... the vice is usually where I put the nicropress... (so I can have two hands free to keep everything in place on the cable before I press it) but I think this is a better use of the vice.
Thanks!
Thanks, you are a champ for doing these vids.
back off the adjustment on the crimper to get the first press and hold things in place, then go back and do it again at the final setting
grab the cable and sleve with a rag in your hand, then you can really push it up against the thimble.
you can hold things in place with a regular cable clamp too, just gently tighten it, you don't need much, it leaves no damage to the cable
Thank you for sharing this. The Cleco pliers are perfect for this application.
I would like to respectfully mention some facts about plated copper Nicopress sleeves.
Nicopress sleeves are designed for Flexible cable. Not strand (1x19, 1x7 etc). They will work with strand, but a copper sleeve is designed for 7x19 (shown), 6x19 and its variations like IWRC, or even 6x7 or 7x7.
They are manufactured by and are a trademark of the National Telephone Supply Company. There are many other manufacturers of oval sleeves as well. They are for Flexible Wire Rope, not electrical wire. Not "telephone" wire. GAC? Yes.
There are other types of Nicopress sleeves too: Round stop sleeves, aluminum oval sleeves for fibre rope etc. These are Oval Sleeves. For Flexible Cable you can use plain copper sleeves or preferably plated copper sleeves.
I am calling the size in the example 5/32". It is hard to eyeball something in a video, but if it were 3/16", the sleeve would be noticeably longer in length, relative to its width.
If it were 1/8", it would be tiny compared to the size shown.
This sleeve will expand in length 5/32" after being pressed 3 times with an M die. This is the rule of thumb for all Nicopress sleeves: they expand the same amount as the cable diameter after pressing is finished. There will always be one die designation in any application that is most popular, like the M die I mentioned, but there are often other size dies that will work as well. They will always have a maximum finished sleeve make-or-break diameter, and a specific number of presses required by specific dies. Using an M die, this sleeve gets 3 crimps.
Sometimes the same die will work with different diameters. 3/16" and 7/32" cables use size - specific sleeves but they can both be crimped with an "X" die.
According to the manufacturer's instructions, which are the same as the instructions from Universal Wire Rope and other manufacturers btw (some out of business), the cable end Must protrude from the sleeve after pressing is finished, a minimum of "One cable diameter" if you expect 100% strength. So if the sleeve is going to expand 5/32", and we want 5/32" sticking out after pressing, then you will need to start with 5/16" sticking out.
Except: if you start pressing at the middle of the sleeve, then the sleeve will expand towards the thimble when you do the crimp next to the thimble. The finished sleeve should not touch the thimble. I aim for 1/2 of the cable diameter = the space between the thimble points and the finished sleeve. If, after swaging, the thimble is jammed against the sleeve, or causing the thimble to angle-off, then that swage should be rejected.
In my line of work, we don't care if the swage is absolutely 100%, and so we try to end up with the cable end flush. This is so that people handling the cable don't get poked or injured by the protruding end. Cutting the excess cable off flush with a grinder/cutoff wheel is not recommended- it is too easy to nick the working part of the cable. Just the slightest scratch from an abrasive wheel will absolutely ruin the eye. How will the inspector know if the cable is injured or nicked if there is heat shrink covering the swage? Heat shrink makes the swage look better, but I would not use it for flight controls.
I guess this is obvious to many people, but I have seen it done wrong countless times; the sleeve is oval shaped in section. That's why they're called oval sleeves. The sleeve must nestle in the circular groove of the die. Close the die around the sleeve, and before applying any pressure, do your final adjustment. Then close the die. I cannot tell you how many times i have seen sleeves crimped sideways, or detented by the tip of the tool instead of enclosed by the circular die.
It helps to have one arm of the swaging tool in a vise, holding the tool stationary. I intend to not use my cleco tool in the vise, but to let the vise hold my Nicopress tool instead.
If you wish to swage the middle of the sleeve first, that's fine. Just leave enough room for expansion between the thimble and the oval sleeve. Does that mean that the middle crimp should be exactly in the middle? If it is a hair short of the middle - a bit farther from the thimble - then the squeeze next to the thimble can be a bit farther from the thimble as well. This will make a nicer "bell-mouth" at the throat of the eye.
Always complete your crimps with One closing of the tool, not repetitive crimps in the same spot. If it doesn't measure in, adjust the tool using the manufacturer's instructions. Never turn any screw or bolt on a closed tool. Always open the tool first. Keep your swaging tool lubricated. I use Triflow.
I personally always rotate the sleeve 180 degrees relative to the press I just did, adjacent to the press I'm doing next.
The crimps on the sleeve should never overlap. There should always be a ridge of flashing between presses.
The crimp should never be flush with the ends of the sleeve.
I do not believe that two sleeves crimped in series are stronger. I have never seen any manufacturer recommend this for creating loops. But I have used a second sleeve to cover the sharp cable end many times. When I do that, I do (a) very light partial crimp(s) on the second sleeve covering the sharp cable end. There must be adequate distance between the two sleeves, I use 1-1/2 pics of the cable lay (you could say the pitch of an individual strand + 50%). If two sleeves are used in the name of strength, it is an illusion. If they are too close together, there is a hard spot created between the sleeves which will destroy the integrity of the swage. If two sleeves are used and the order of pressing is such that the presses are converging towards each other, it will create an imbalance which will also destroy the integrity of the splice.
Sometimes I put a blob of non-silicone adhesive caulk (like Sudbury Elastomeric Sealant) or maybe some Loctite GoTo Glue, on the exposed cable end, to prevent people from getting poked by the sharp cable end.
Tip: Start by making a ring around the cable with a sharpie, 18" from the bare end. Make your swage loop. Then measure to the sharpie ring again, and subtract that number from 18. That is how much cable you will need to add to the other end before cutting in order to hit your correct finished cable length. Measurements are made to the inside bottom of the loop when referring to the finished length.
One rule we live by is never cut any cable until you absolutely have to. Always start with way more extra than you think you'll need. Then you can reject the first attempt without ruining the whole thing.
Always cut aircraft cable with cable shears designed for cutting flexible steel cable. Bolt cutters, dikes, and electrical cable cutting shears are not appropriate. If you want to use a wheel to cut your cable, OK. I use cutoff wheels on cable over 1/2" dia all the time. But it will leave the cable in an unbalanced condition. Make sure the strands are not fused together. Using a cutoff wheel or torch to cut cable is not recommended.
some cleco pliers is useable to install studs too, like wheel center caps of 737 or Bombardier Q400 panel studs...
Awesome vids!
Thanks for your master teachers
Excellent tip.
BRILLIANT!
Sure now I see this AFTER I made all the cables! LOL!
There is a better way unravel the wires in interlace some coil back
That is a method for "soft" eyes, not thimble eyes. Forming a Flemish eye in the cable before inserting the thimble will make an eye that is too large for the thimble. Yes, it's a better loop, but not practical with thimbles.
I just don't see it.
Cara chato... basta mostrar que todos entendem!