Electrical Connector Question

[PCHunt]

I'm replacing the wiring in my tail section. I'm familiar with Molex connectors, but wondering if there is a better solution. Smaller, more robust, easier to use?

I need a 2-wire connector for the white tailight, and a 3-wire connector for the separate strobe.

Any suggestions will be appreciated!

 

[rocketman1988]

Recommend

I use Deutsch connectors for everything and they work great.

 

[fixnflyguy]

Cheap and easy "Handshake" connetors

I like the cheap and easy Handshake knife connectors..slide a piece of clear Tygon over them and they allow pretty quick removal when needed, Not high tech and sexy, but has been the long standard of the type connections you are looking for.

 

[JDA_BTR]

I used Dsub pins leftover from my harness construction and heat shrink when my tail molex connector didn't make it through the first 20 hours. Each one a little further up than the last. Keeps it thin and small.

For larger wires easiest are the insulated Faston PIDG connectors like this, either red or blue depending on wire gauge:
https://www.digikey.com/en/products/detail/te-connectivity-amp-connectors/735279/1153928

There is a cheaper similar product, but not as reliable:
https://www.digikey.com/en/products...G4Xa__-47Hi4TfZjbPX9cvLgO47DJKxhoCEUoQAvD_BwE

But in your application where it won't be changed for decades, the Faston PIDG butt splices would work well too really don't need a disconnect feature.
https://www.digikey.com/en/products/detail/te-connectivity-amp-connectors/323975/287718

Solder splice fasteners are nice too if you have any laying around from other work but the really good ones from TE are best the Amazon ones can be flaky.

 

[KatanaPilot]

I use Deutsch connectors for everything and they work great.

What Bob said. I used the machined, gold-plated pins and have never had an issue. Molex connectors are ok, but Deutsch connectors are install and forget. Dsubs are a better choice than Molex in certain situations as well.

 

[wirejock]

D-sub

I planned Molex but changed my mind because D-subs are more conductive. All connectors are D-sub of one size or another. In fact, I have a lot of six pin Molex if some wants to make an offer.
My plan at the tail is to run both trim and beacon to one D-sub. Female from the front. Male toward the tail. If I need to take something apart, I can pop those pins out pretty quick. Almost as fast as a Faston blade and the male pins will go through snap bushings easy.

 

[AlpineYoda]

Depending on how much current is being carried, I used a combination of d-sub pins and push-on connectors for most connections. In both cases, I usually put heat shrink tubing over the finished connection to make sure vibration could not pull them apart. Cheap, easy. And easy to replace / upgrade when needed.

For a couple of things, where I had to splice wire bundles together, I mounted terminal blocks and used crimp-on ring connectors.

 

[Mike S]

I like the cheap and easy Handshake knife connectors..slide a piece of clear Tygon over them and they allow pretty quick removal when needed, Not high tech and sexy, but has been the long standard of the type connections you are looking for.

Yep, I like them for higher current items.

For low current stuff, I use Deans connectors from the R/C world. They are soldered connections however, so be sure to support the wire correctly to prevent breakage.

 

[JonJay]

I used Dsub pins leftover from my harness construction and heat shrink when my tail molex connector didn't make it through the first 20 hours. Each one a little further up than the last. Keeps it thin and small.

For larger wires easiest are the insulated Faston PIDG connectors like this, either red or blue depending on wire gauge:
https://www.digikey.com/en/products/detail/te-connectivity-amp-connectors/735279/1153928

There is a cheaper similar product, but not as reliable:
https://www.digikey.com/en/products...G4Xa__-47Hi4TfZjbPX9cvLgO47DJKxhoCEUoQAvD_BwE

But in your application where it won't be changed for decades, the Faston PIDG butt splices would work well too really don't need a disconnect feature.
https://www.digikey.com/en/products/detail/te-connectivity-amp-connectors/323975/287718

Solder splice fasteners are nice too if you have any laying around from other work but the really good ones from TE are best the Amazon ones can be flaky.

These are the exact methods I use for a few wires here and there. In reality, you won’t have to disconnect anything very often. Other than a few wiring upgrades over the years, most connections will rarely, if ever, be touched. The only reason to use any high density connectors is size, keeping things compact. For a few wires, you just don’t need high density connectors.

 

[PhatRV]

I used the DB9 connectors to bundle all the wires, including trim, at the back of the fuselage. Instead of using the chubby DB9 housings and screws, I safety wired the two DB9 connectors together using the thin 0.032 wires.

 

[N804RV]

I like the cheap and easy Handshake knife connectors..slide a piece of clear Tygon over them and they allow pretty quick removal when needed, Not high tech and sexy, but has been the long standard of the type connections you are looking for.

Every one of those stye connections I've ever seen on an airplane (even with the clear tubing over them) has had corrosion.

In fact, where a good quality low-resistance connection is critical, this style connector is specifically called out as unnaceptable by at least one avionics manufacturer.

If you have to use something other than sealed environmental splices (in the tail expecially), either use Dsub connectors fastened together with 4/40 screws and nuts and wrapped in silicone self-fusing tape, or get some Deutsch IP67 rated connectors with the barrel-crimp style pins. You'll have to buy the crimp tool. And, you'll have to strip the wire long and double it over to take up enough space in the pin to get a solid crimp.

I use Raychem environmental splices in areas that may be subject to water intrusion (like the vertical fin and rudder fairings).

 

[PCHunt]

Great input, thanks!

As I suspected, some excellent comments from the VAF crowd!

Lot's to learn, and your advice much appreciated!!

 

[JonJay]

Every one of those stye connections I've ever seen on an airplane (even with the clear tubing over them) has had corrosion.

In fact, where a good quality low-resistance connection is critical, this style connector is specifically called out as unnaceptable by at least one avionics manufacturer.

If you have to use something other than sealed environmental splices (in the tail expecially), either use Dsub connectors fastened together with 4/40 screws and nuts and wrapped in silicone self-fusing tape, or get some Deutsch IP67 rated connectors with the barrel-crimp style pins. You'll have to buy the crimp tool. And, you'll have to strip the wire long and double it over to take up enough space in the pin to get a solid crimp.

I use Raychem environmental splices in areas that may be subject to water intrusion (like the vertical fin and rudder fairings).

99% of the fleet just got grounded. Blade style connectors, fuse blocks, sub D’s, even shrink wrapped pins don’t meet that interpretation.

 

[PilotjohnS]

DTM series

I used the DTM series connectors almost exclusively.
They use the really good crimp pins, are easy to assemble and disassemble, waterproof and have good strain relief for the wires.
i cant think of a better connector.


The D-subs don't have strain relief unless one uses the back shells; and then I find them to be bulky. OK for test equipment, but really too much for airplanes.
I have never had reliable connections with the Molex.

Its is easy to put the proper connectors on during the build, but it is much harder to retrofit an existing build.

 

[TASEsq]

It’s all about the contact rating

It all depends really on how many amps you need.

I have found so far in the tailcone and wing wiring that the dsubs seemed like a good idea but are very bulky, and not easy to mount the connector anywhere - need a big and weird shaped hole. Basically only good for signal and avionics wiring anyway due to contact amps rating. You need a dsub crimper but they are cheap. I’ve used dsub pins with no connector in the elevator to join the trim motor to the wiring.

The deutsch dtm are a better - up to 7.5 amps. Again though hard to mount the connector. You can get little plastic clips which you can bolt on, but the hole is way too big. They are a PIA to get the connector off the clip once installed. I’ve riveted the clips on using a flush pull rivet, but they connect to the male side of the connector which is a little annoying. Photo of how I used a dtm to power my roll trim servo. You can crimp the pins using a dsub crimper but they don’t take dsub pins - they take their own pins which look a lot like dsub but are not the same.

Finally there are cpc. I like these. They are easy to mount in a circular hole and come in 2 series. They come in “reverse sex” which allow the female to be the panel mounted connector. Series 2 take dsub pins and therefore only signal and low power avionics - can crimp with a dsub crimper. Series 1 take power pins up to 13 amps and you crimp with a molex style crimper. Photo of how I’ve used these on my wing connectors.

I was totally bamboozled by all the choices so made a reference document you may find useful: https://drive.google.com/file/d/1cw7OPO0I_RDc_H0VNA7YjZ_BSVK-W-RA/view

 

[Walt]

Nice job on the document, will come in handy!

 

[RVbySDI]

It all depends really on how many amps you need.

I have found so far in the tailcone and wing wiring that the dsubs seemed like a good idea but are very bulky, and not easy to mount the connector anywhere - need a big and weird shaped hole. Basically only good for signal and avionics wiring anyway due to contact amps rating. You need a dsub crimper but they are cheap. I’ve used dsub pins with no connector in the elevator to join the trim motor to the wiring.

The deutsch dtm are a better - up to 7.5 amps. Again though hard to mount the connector. You can get little plastic clips which you can bolt on, but the hole is way too big. They are a PIA to get the connector off the clip once installed. I’ve riveted the clips on using a flush pull rivet, but they connect to the male side of the connector which is a little annoying. Photo of how I used a dtm to power my roll trim servo. You can crimp the pins using a dsub crimper but they don’t take dsub pins - they take their own pins which look a lot like dsub but are not the same.

Finally there are cpc. I like these. They are easy to mount in a circular hole and come in 2 series. They come in “reverse sex” which allow the female to be the panel mounted connector. Series 2 take dsub pins and therefore only signal and low power avionics - can crimp with a dsub crimper. Series 1 take power pins up to 13 amps and you crimp with a molex style crimper. Photo of how I’ve used these on my wing connectors.

I was totally bamboozled by all the choices so made a reference document you may find useful: https://drive.google.com/file/d/1cw7OPO0I_RDc_H0VNA7YjZ_BSVK-W-RA/view

I like your document. However, it looks to me that the first two pics have labels switched. The “male” label is above a pic of a female pin and the “female” label is above the male pin. Or, maybe I am just confused about what is a male and what is a female these days. Maybe he is a she, or a they or them! I just don’t know anymore! *

 

[TASEsq]

I like your document. However, it looks to me that the first two pics have labels switched. The “male” label is above a pic of a female pin and the “female” label is above the male pin. Or, maybe I am just confused about what is a male and what is a female these days. Maybe he is a she, or a they or them! I just don’t know anymore! *

Ha, yes. Oops. Wrong text. Maybe I label them all they pins?

 

[DCorwith]

Nice document

I like your document. However, it looks to me that the first two pics have labels switched. The “male” label is above a pic of a female pin and the “female” label is above the male pin. Or, maybe I am just confused about what is a male and what is a female these days. Maybe he is a she, or a they or them! I just don’t know anymore! *

Trent: Yes I noticed the male/female in the first pictures reversed; otherwise great document!
Dave

 

[clam]

Nice reference

Great job producing that reference document.
There is also a nice video on the CPC connectors in the EAA Hints for Homebuilders library
https://www.eaa.org/videos/hints-for-homebuilders/electrical/713328494001