Switches: spade vs screw terminals

[DCASonex]

The other thing about the good quality Fast-on's from aircraft suppliers is they have a small flared piece that is designed to capture the wire insulation. The cheapies don't have that and loose holding strength.

Those aircraft grade grade crimp terminals also require special crimp dies with separate portions to crimp wire and the portion around the insulation, not the standard el-cheapo ones in big box stores. (Especially avoid HF's cheap ones. Stripper, crimper I got from them for auto tool box went straight into recycled metal bin after first attempt to use it, would not fully close. Have found Stein Air Inc. to be another very good source for all aircraft wiring supplies and tools.

David A.

[builderflyer]

I use a quality crimper (the type David A just referred to) and quality connectors like those bought from B & C (not automotive ones) and I test each crimped connection by pulling on the wire to be sure it won't move from the connector. But, over time, a few of the wires have still surprisingly loosened from the connector. So I've gone to soldering the tip of the wire inside of the crimped connector to eliminate that possibility (being careful to not allow any solder to wick any significant distance up the wire especially to where fatigue of the wire could become an issue). Sort of like the "belt and suspenders" principle. Worth the extra time to me.

Art,,,,,,,,,,,,,,,,Sonex taildragger #95,,,,,,,,,,,,,,,,,,,Jab3300 #261

[n982sx]

Frankly, after using nothing but spade terminals from B and C for my Sonex, I wouldn't even consider using screw on terminals. The fastons work great and hold well. Get a good crimper, good quality terminals and you're set. You'll never go back.

On my 14, I have a couple of places aft of the firewall where the component forces me to use a ring terminal to connect to a cheap screw mount and they are the most concerning to me.

[WaiexN143NM]

Hi all ,
Another good practice is to use some shrink tubing around the crimped connector and the wire. Helps support the crimped wire, and keeps moisture out.

WaiexN143NM
Michael

[lutorm]

I've had spade connectors (OEM ones) vibrate loose on various motor vehicles, so I'm not fond of them at all. Maybe if you use high enough quality they're mostly OK, but I much prefer a connection method that has a positive means of retention. Also, if they're at all exposed to the elements, once you get some corrosion in there things are going to go downhill.

These days, there are many high-quality weather-sealed connectors one can use. I've used Metri-Pack, which are good for current-carrying wires but a bit on the large side, Ampseal (good if you have a lot of connections, like 23 or 40 pins) and Mizu P-25 (2-4 pin, tiny). You need an open-barrel crimp tool but nothing fancy, $30-40 bucks and you get something decent that works well once you learn how to do it.

[9GT]

For all your electrical and Avionics needs I highly recommend Steinair. They carry aviation grade and quality electrical supplies and avionics at GREAT prices. Phone consultations and advice are always welcome also. They generally ship on the same day ordered also. No relation,,,just a satisfied customer. http://www.steinair.com/

[NWade]

I've had spade connectors (OEM ones) vibrate loose on various motor vehicles, so I'm not fond of them at all.

That's understandable - most of the automotive spade terminals are crap - definitely loose and wide tolerances in size. I would never use automotive spade terminals in an aircraft. They look almost identical to decent-quality aircraft spade terminals, but they're not created equal. See my previous post on page 1 of this thread, where I illustrate some recommended and non-recommended terminals. The difference under actual connection and use is massive.

--Noel

P.S. My Sonex is not yet flying, but I've used spade terminals for all of my Sailplane wiring for 10 years and never had a good-quality connector come loose from its fitting or have a wire drop out of a crimp connection, despite flying in all kinds of turbulence (rough air = lift)