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Fat wires and the pull test

LettersFromFlyoverCountry

LettersFromFlyoverCountry

Well Known Member
Generally speaking, if something doesn't work out the way it should on my RV project, I assume it's something I've done wrong. But this evening, I'm a little concerned that that may not be the case.

I was reinstalling the fat wires on the battery, to power up the Vertical Power 50 system and test out my long-running installation of the radios in N614EF.

When I dug the ground wire (from battery to firewall) out of the work cabinet, where I'd stored it since removing it a month ago, I notice one connector was missing.

This is the P9 wire, which I bought from Van's because I didn't really want to build these things myself. So for about $15 a pop, I figured what the heck.

I twisted -- slightly -- the other connector and gave it a slight tug and off it came!

Then I checked the P14 (battery to master), slight tug.... voila! Both ends.

I checked another Van's cable I had around -- a P14, I believe, and the connectors did not seem to twist off.

Because there's heat shrink on these things, you can't really tell much about their construction until they come off, but I see no signs of solder and no signs of crimping. It looks like they just slapped a connector on, slapped some heat shrink on, and mailed it out.

Is this the way it's supposed to be? It's got me a little spooked that I could've been flying around, and had some pretty important cables fall apart.
 
Wiring

No, it's not the way it's supposed to be. Suggest you call Van's and advise them of the problem. They may have a bad batch on the loose.

Mike
 
Needless to say, Bob, I know of a really nice little tool that'll swage those terminals on so tight, you could hang the entire airplane off just one connection.

:D:D:D:D:D
 
I seem to remember that Van's provided a notice or service bulletin a year or two ago mentioning that they had a bad batch and that you should check them with a 50# pull test. My memory could be flawed though.
 
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Well, here's the thing. Van's knows who bought these cables. Why not send out mail to those people to alert them. This is a pretty serious thing and I would think relying on people to go to the Van's site to see if maybe their product has a problem would seem an unreasonable burden on the builder.

The only SB I can find on it is this one. It's from October 2006. I purchased these last summer.

I guess my real problem is that someone was put in a job where he/she/it thought sticking a connector on a wire and sticking some heat shrink over it constituted properly construction technique. And that someone shoved it in the shipping container without likewise giving them a tug. Lousy quality control.

I just stuck a video up on the blog.
 
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Stabird said:
Had the same problem a few years ago. Solution is simple. Solder the connectors.
Click to expand...

I tossed 'em out. I figure if this rather obvious defect slips through, I can't trust the quality of any aspect of it. I'll make my own, or order custom ones with a company I can trust -- B&C, for example.
 
I had mine made at the local NAPA. They have the cable, the cutters, the good crimpers and heavy duty heat shrink........plus the guy liked to hear about my project instead of another farmer story.
 
simply disturbing

There's really no excuse for quality control that bad, and all the worse that either the problem recurred or known bad inventory was still shipped.

There was a fatal rv10 crash some time back that was ultimately traced to a poor terminal connection on a fat ground wire. The wire was not from van's. Rather, the builder reportedly made the bad wire, but it demonstrates the importance of those terminal crimps on the big fat wires.

Thanks for sharing.
 
They should be crimped not soldered

When you have worked with electrical and electronic systems and manufacturing of them all your adult life you develop the attitude that everyone knows how wires are terminated and what properly terminated wires look like. Your post was a shock to me and it awakened an awareness that people that are not experienced in the field are vulnerable to shoddy workmanship and a total lack of quality control in this critical area by the manufacturer and supplier. I toured Van's old facility in North Plains and I have been to the new one but not toured it. I saw no evidence of any wiring activity at all so I'm sure these are manufactured elsewhere but as the supplier Van's is responsible for the wire terminations supplied by them. Van's is a terrific airframe kit supplier but from your experience and the SBs mentioned here I would not buy any wiring from Van's period. Crimpers are very expensive and the time required to install terminals is not trivial but worth every penny & minute compared to buying a "pig in a poke" set of wiring that may not be the right length and worse - improperly terminated.

Bob Axsom
 
gbrasch said:
Bob, was that a long sleeve shirt and jacket that you were wearing in the video?:D
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That just goes to show you what passes for "normal" changes from location to location.

It hit 70 degrees yesterday when I stopped at the hangar for a little work. The hangar door was up and it was gorgeous. I was able to leave the parka home. This morning -- before sunrise -- I took the dog for her walk w/o checking the temperature, put on my parka, hat, and gloves, only to get out there and find out it was 59 degrees --- shorts weather. I looked like an Arizonian. :p

Shoulda seen me the day before when I was working on the plane in a shirt and tie.
 
Bob Axsom said:
Crimpers are very expensive and the time required to install terminals is not trivial but worth every penny & minute compared to buying a "pig in a poke" set of wiring that may not be the right length and worse - improperly terminated.

Bob Axsom
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I'm ordering the terminal crimper today. I can't say I'm happy about spending $150 I hadn't planned on spending, but what's the price of piece of mind. Moreover, it's a good reminder that *I'm* ultimately the one responsible for the safe conduct and building of this airplane and to stop assuming that just because a part came from a company that knows more about building an airplane than I do, I should check, recheck, and triple check that a product meets *my* standards for quality rather than assume it's sufficient to pull something out of the box and install it. I'm just glad I learned the lesson before it was too late.

I would strongly suggest anyone who's bought battery cables from Van's in the last year or so, pull them off and check them. It's highly, highly unlikely that these two cables were the only ones that were built by someone who didn't know what he/she was doing.
 
Bob,
I had a similar experience with my Van's supplied fat wires. I was having trouble getting eveything working properly on the EMS portion of my Dynon EFIS and I found loose terminals on my engine ground wire. I tossed it and bought one from NAPA. I bought Van's wiring kit, which I wouldn't do again. Unless your electrical system is exactly like the Van's diagram, you end up not using very much of it. It's cheaper and neater to do it on your own. An interesting side note: I seem to remember there were some 'sub-kits' you could get with the wiring system kit. I think one was a 'switches kit' or something like that. I checked Van's individual prices on all the switches and parts in the kit, and it was less expensive buying them that way - from Van's - than paying the 'kit price'. Seems like it should be a little less expensive to buy the kit - at least that's the way I assume things to be.
 
There is a crimp tool that appears can do the job and is significantly less expensive. It's currently on sale for $7.99 st Welding Supply. Look about half way down the page.
 
Swaging

Bob,
Other tools work...more or less, depending on design but you'll be happy with your Terminal Tool.

It shrinks/compresses the terminal much better than any other tool I've seen.

I use mine with a torque wrench (torque settings are specified in the instructions) and get uniform results every time.

Good luck,
Mike
 
Papa's got a brand new tool.

termtool_5.jpg
 
I soldered mine too. Then I crimped them with a wedge and a vise. My pull test was me pulling as hard as possible, I am pretty sure it'll never fail. The crimp tool is really nice, but $$. I had a failed crimp after using a tool from Stein. So I contacted him and it turned out it was operator error (me dummy). Stein, you should contact Van's. It's difficult to improve quality without feedback. Your video tells the story. point them toward that. I consider myself well qualified, but I NEVER trust anyone's crimps. Not my own, especially not some one else's.
 
One more thing. It's really really important to "clock" wires correctly. Any twist or strain when attaching them will eventually lead to failure.
 
Bob, thanks VERY much for the nice review of the Terminal Tool. You got one of the last tools to ship with the 17-4 stainless die sets. We're sending the last few of those to Stein today.

That #2 terminal will never separate from the wire. With 90 ft-lbs, you applied approximately 54,000 pounds of pressure to the ferrule, shrinking the terminal and wiring inside to a near solid state. At that pressure, the wire strands get plastically embedded into the inner ferrule wall. No other hand operated crimping tool can do this, as far as I know.

As for the "welding supply" crimp tool someone suggested for $7.99, its a total piece of JUNK. The idea of hammering a big fat spike into the side of the terminal to make the connection is actually scary.

I've now run out of shippable inventory on the TT, but they're still available at SteinAir or Avery. New tools are in the pipeline....
 
Soldering terminals creates a new failure mode

I won't go into it in detail but back in the early 60s I was on the ASA C-99 subcommittee for the development of high reliability solder joints. Before that all of our products (McDonnell Aircraft Co.) used solder joints to terminate wires. Oh well you are going to do what you are going to do anyway - never mind.

Bob Axsom
 
apkp777 said:
One more thing. It's really really important to "clock" wires correctly. Any twist or strain when attaching them will eventually lead to failure.
Click to expand...

But don't most of the premade wires (i.e. Van's) come with the terminals parallel to the other, thus guaranteeing eventual failure in applications like, say, the battery-to-contactor?
 
Bob Collins said:
But don't most of the premade wires (i.e. Van's) come with the terminals parallel to the other, thus guaranteeing eventual failure in applications like, say, the battery-to-contactor?
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I suppose they do come that way. I didn't use any pre-fabbed wiring. I was pretty sure it would only be "roughly" cut and terminated. As you discovered it looks like the terminations were lousy at best.

Admittedly I wish that I had your lug crimper you just bought. Sound's like that thing is perfect. That would be great tool for my EAA chapter to add to their inventory.
 
Bob Axsom said:
I won't go into it in detail but back in the early 60s I was on the ASA C-99 subcommittee for the development of high reliability solder joints. Before that all of our products (McDonnell Aircraft Co.) used solder joints to terminate wires. Oh well you are going to do what you are going to do anyway - never mind.
Bob Axsom
Click to expand...

I was told at one point in time by my very own father (who works as electric engineer) that soldering terminals is one of the biggest no-no in high temp locations (keep in mind that terminal may be heated not only by outside temperature but also by current inside wire). Soldered terminal not only may become loose but also creates big risk that molten solder can flow out of it and can short circuits.
 
Bob Collins said:
You want to borrow it?
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No, thanks Bob. That would be awesome though. I am pretty confident in my connections. For sure the peace of mind in having the right tool is always a big deal. I really looked at buying that tool when I was making the connection. We used something very similar at UAL and I doubt the connections will ever fail.

Like others I don't like the idea of solder terminals. To be clear, I did both, first I soldered then I crimped. Had I had your tool Bob, I would have skipped the solder step.
 
As for the "welding supply" crimp tool someone suggested for $7.99, its a total piece of JUNK. The idea of hammering a big fat spike into the side of the terminal to make the connection is actually scary.
-Bill Wightman
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I think you scare pretty easily. Your tool looks pretty nice, but is it more than adequate?, for a guy who has to make maybe 10 swages on his project? Don't misunderstand me: I would love to buy every beautiful tool there is for building. And I have some nice ones too. But there are times when I need a tool for one, or a very few jobs. Have you used the tool?, (before criticizing the competition?)
 
True....

Bob Axsom said:
I won't go into it in detail but back in the early 60s I was on the ASA C-99 subcommittee for the development of high reliability solder joints. Before that all of our products (McDonnell Aircraft Co.) used solder joints to terminate wires. Oh well you are going to do what you are going to do anyway - never mind.

Bob Axsom
Click to expand...

...but even into the 70's we were using soldered terminals on equipment that would survive a Saturn V launch and a Viking mission to Mars...:cool:

Soldering done properly, and supported is not bad.

In a similar vein, crimping should be done right too... in an aerospace production environment, the tools and the operators are calibrated daily. I've seen bad crimps too....:)
 
Lux Wrangler said:
I think you scare pretty easily. Your tool looks pretty nice, but is it more than adequate?, for a guy who has to make maybe 10 swages on his project? Don't misunderstand me: I would love to buy every beautiful tool there is for building. And I have some nice ones too. But there are times when I need a tool for one, or a very few jobs. Have you used the tool?, (before criticizing the competition?)
Click to expand...

I agree. My cables using this $7.99 tool more than pass a pull test. Plus, it does a nice job of distributing the squeeze around all sides of the cable. FWIW, I just put the tool in my vise and squeeze it rather than hammering, though hammering works too.
 
William Slaughter said:
What material are the die sets going to be made of in the future? Just curious, I already have my Terminal Tool.
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The new die sets are AISI 6150 steel, heat treated to Rockwell-C 40. They're black oxide coated, and laser etched with white markings. Not ready quite yet though...
 
Jim,

We know the eight buck tool is out there and is used occasionally on homebuilt aircraft projects. As long as there's freedom for consumers to spend their hard earned dollars as they see fit, the cheap tools will sell. So will the nice ones.
 
James C

I usually don't respond much in these threads but rather just read. I worked with Bill in the development of the terminal tool although Bills engineering background was a necessity to product what is now being sold. It seems there is some concern about the price of the tool and understandably so. It took that to put Made in USA on the product.
Considering 42 gallons (If memory serves the typical RV total fuel capacity) of 100LL at 3.50$ a gallon is 147.00$ or a burn rate of 12 gallons per hour is 42.00$ for an hour of flight time 150.00$ doesn't seem too far out for peace of mind at 8000 feet.

Thanks to all who have purchased The Terminal Tool.

James.
 
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You might be able to borrow a crimper....

...cozy up to your favorite local electrician. They don't all carry them on their trucks but most have one in their shop. Most electrical wholesale houses have one avialable too and will let you use the tool if you buy their terminals. Home Depot may have them in their tool rental stock but I have not checked. So, if you know anybody in the commercial electrical business, neighbor, friend, or have a small local electrical distributor branch near you, just ask them.
 
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