Originally Posted by abuura
I wonder whether anyone has used connectors by Posilock
. Seem to be a great idea, if somewhat bulky if there are many wires involved. Perhaps one of our electrical-smart builders could peruse the website and render an opinion?
I took a look at them and have a few comments:
Not "aerospace quality" (what ever that means, I'll try to explain)
It's not that I don't like them, they are cute but I don't see a big use for them in an aircraft. When you wire you will try to have continuous (permanent) runs from source to termination in the first place, no joints.
If you're thinking about using the posi-lock try this: Get some 22 or 20 gage mil spec aircraft wire and pull on it and see how good they hold? My guess is they will pull apart? If they do, they are totally unacceptably obviously. Also what keeps them tight and from unscrewing.
To make a connection the "standard" for kit planes are "crimp terminals" (1)
, not that they are perfect; in fact if poorly done, crimp joints are lousy. However with a quality crimp fitting and crimp tool, you can make very good connections, both electrically and mechanically with a little practice. The crimp spice is easy to make and is lighter, cheaper, stronger than above (I think). The only down side with a crimp joint, besides a little skill, is you need a good quality tool.
One of the things that keeps a good electrical connection is pressure. With the posi-lock it looks like the wire is just pushed together with little pressure. Over time, corrosion could cause increased electrical resistance? Also what about fire and heat. I see they are UL listed, so they should be OK?
These little things are best for wiring light bulbs in you house not your plane in my opinion. Not that they might not work? The BIG claim to fame is they require no tools and are reusable. Neither of these are big issues when building an airplane.
An alternate method to crimping is soldering. In general it's not good practice since solder can wick into the wire strands and makes them act as one. With flexing the strands are unable to act separately; this tends to make it subject more to fatigue failure. That's one reason why we don't use solid copper wire in planes. However, if you solder in such a way that there's no flexing where soldered, by using some kind of support or strain relief, it's not an issue. I have been known to solder and use a few pieces of heat shrink tubing to prevent flexing of the solder joint. Also don't glob the solder on and keep it localized to the immediate joint. However quality crimp joints as mentioned are easy and quick with a good quality crimp tool (not the el-chepo auto store crimper).