The International Cessna^® 170 Association

Making up some new 4 AWG battery cables. Should I crimp or solder them? Or both? I do have a hydraulic crimper like this one

https://www.amazon.com/Hydraulic-Crimpe ... re+crimper

Just wondering what other have done. I think Mil-Spec calls for crimping....

Crimp only should work fine. I have only seen solder used on small butt connections.

Which ever way you use be sure align the connectors on the cable so they will align with the terminal lugs. Cable this thick does not really twist like smaller gauge wire.
I used solder pellets and they worked great. http://www.delcity.net/store/Terminal-S ... 103464.t_1

I was about to say that would be one heck of a large soldering iron. But then I watched the install video Karl linked. Pretty cool.

Nippaero, at least for smaller gauges, crimping is preferred because soldering tends to stiffen the wire at the connection, which can cause stress risers and shorten the life of the connection. I changed what appeared to be the original battery and starter cables and ground strap on my plane last year, and they (the originals) were all crimped (and lasted decades). I crimped the new ones as well, but used the heavy-duty, long-handled crimper we had at the shop. I've heard that the hydraulic crimpers like the one you've identified do a good job as well, but I have not used one. I like the fact that it does a hex crimp. If I were you, I wouldnt hesitate to crimp your cables with your crimper.

gfeher wrote:Nippaero, at least for smaller gauges, crimping is preferred because soldering tends to stiffen the wire at the connection, which can cause stress risers and shorten the life of the connection. I changed what appeared to be the original battery and starter cables and ground strap on my plane last year, and they (the originals) were all crimped (and lasted decades). I crimped the new ones as well, but used the heavy-duty, long-handled crimper we had at the shop. I've heard that the hydraulic crimpers like the one you've identified do a good job as well, but I have not used one. I like the fact that it does a hex crimp. If I were you, I wouldnt hesitate to crimp your cables with your crimper.

Exactly.

gfeher wrote:Nippaero, at least for smaller gauges, crimping is preferred because soldering tends to stiffen the wire at the connection, which can cause stress risers and shorten the life of the connection. I changed what appeared to be the original battery and starter cables and ground strap on my plane last year, and they (the originals) were all crimped (and lasted decades). I crimped the new ones as well, but used the heavy-duty, long-handled crimper we had at the shop. I've heard that the hydraulic crimpers like the one you've identified do a good job as well, but I have not used one. I like the fact that it does a hex crimp. If I were you, I wouldnt hesitate to crimp your cables with your crimper.

I can see this possibly being an issue with smaller gauge wire but I don't think it is really an issue with larger "cable" gauge material. Even with the smaller gauge wire I wonder. I just finished completely rewiring my aircraft and while I used crimped connectors through out, except the cables, couldn't help but notice that all the 63 year old soldered connections were in great shape.

I hear you Karl and wonder as well with respect to large gauges, like for battery cables. I think crimping is easier though if like Nippaero, you already have a crimper to do the job. Either way, if done correctly, the cables should last a long time. So as a practical matter, the debate may be somewhat academic.

We crimp all our cables on the helicopters at work and that is considered a much more severe environment than our smooth Cessnas. On the other hand, my Dad soldered terminals for years and years and they are still good today. I wouldn't hesitate to use either method. Since I have access to the proper crimpers at work that's my preference, but if I didn't I would solder them.

DEM

Thanks for the suggestions guys. I ended up just using the crimper I had. They durned out fine. That 4 AWG wire is pretty stiff. I have used quality 4 AWG welding wire on two RV's and a Challenger II I recently rebuilt. Much more flexible. So I am learning new things with the 170.

AC43.13-1b, Acceptable Methods, Techniques, Materials, etc.... Chapter 11, Electrical, Paras 11-103 Junctions, 11-167 Splices, 11-174 Terminals... time and again states words to the effect " Ensure that only aircraft manufacturer approved devices, such as solderless type terminals, terminal blocks, connectors, disconnect splices, permanent splices, and feed-through bushings are used for cable junctions. ..."

and

"Solderless, crimp connections are preferred... over soldered..."

The reason is as previously stated. Soldered connections stiffen the wire-ends making them subject to breakage from vibration, and corrosion from dissimilar materials.

Whenever possible, use aviation quality wire and crimp-style connectors.

gahorn wrote: "Solderless, crimp connections are preferred... over soldered..."

The reason is as previously stated. Soldered connections stiffen the wire-ends making them subject to breakage from vibration, and corrosion from dissimilar materials.

Whenever possible, use aviation quality wire and crimp-style connectors.

This was the statement I was questioning. In all my years working on old planes, old cars and old electronics I have never seen evidence of this. Not to say it doesn't happen.
In any case, crimped connectors are usually faster to install.

In a wire-bundle, or conduit, or even single-conductor routings along structure, the connection or splice is usually supported alongside with clamps, spaghetti, or other wires, so movement is almost nil and the vibration has less effect. But imagine a wire leading from the engine accessory to the firewall,...as it dangles in open air, with one end attached to a non-moving firewall and the other to a shock-mounted engine... considerable vibration and movement will affect the connection.
However, in general, AC43.13 provides guidance which is consistently advisable in all cases. (Soldered connections are not prohibited...but the vulnerabilities of that type are real.)