Fast on connectors - Page 2

cenutting · #11 08-23-2006, 09:07 PM

You can find the good PIDG insulated terminal crimper that Van suggests at Klein Tools. A website that sells this is "www.rimindustries.com". The crimper for the Molex/ D-subminiature pins can be bought at B & C,
www.bandc.biz/parts.html. Do not use the "oval" shaped cheap crimpers for anything except as a paper weight.

rlo1 · #12 08-30-2006, 09:27 PM

Steinair has a nice selection of reasonably priced tools. Fast service.

JonathanCook · #13 08-31-2006, 09:00 AM

In addition to Bob Nuckolls' book he also has many reference articles on his web site. I found myself reading almost all his web articles one night. (How the time passes when you are having fun.) The articles are at http://www.aeroelectric.com/ARTICLES.HTML . A few articles relating to crimping and fast on connections are

http://www.aeroelectric.com/articles...rimptools.html

"FastOn vs. Ring Terminals . . . What's the Difference?"

Here is a critical review on methods of wiring including crimping vs. sodering and faston vs. threaded terminals and what Bob Nuckrolls' recommends.

http://www.aeroelectric.com/articles/rules/review.html

Good reading.

Jonathan

Davepar · #14 08-31-2006, 10:56 AM

Quote:

Originally Posted by rlo1

Steinair has a nice selection of reasonably priced tools. Fast service.

It took 4 business days to ship my order placed last week. Not fast.

Sprig · #15 09-08-2006, 02:34 AM

I suspect, that just as the name sugests,,,, that Fast-ON = FASTER-OFF in flight conditions.

I'd NEVER use one. PERIOD.

Quote:

Originally Posted by uk_figs

I have been reading the Aeroelectornics book in preparation for starting some wiring and notice it refers to "fast-on" crimped connectors which look a lot like the automotive spade connectors, is this what most people use for connection to power busses etc? Are these different than the automotive parts for the higher vibration environment of an aircraft?

Of course, I might be wrong. Thankfully it won't be MY plane that has a failuremode experienced above.

Sprig

William Slaughter · #16 09-08-2006, 05:00 AM

As Steve posted above, high quality versions of these connectors are not going to come loose accidentally. They are tight, tight, tight. I buy only the Tyco/AMP brand connectors (both FastOn and ring terminals), which are available from SteinAir, Digikey and other sources. I started with an AMP Pro Crimper II crimper and terminal kit from Digikey, and bought additional terminals from SteinAir. This combination is just a joy to use. Regardless of which type of terminal you choose, ring or FastOn, be sure and do a pull test for each terminal size/wire size combination.

Jamie · #17 09-08-2006, 05:15 AM

Quote:

Originally Posted by Sprig

I suspect, that just as the name sugests,,,, that Fast-ON = FASTER-OFF in flight conditions.

I'd NEVER use one. PERIOD.

Of course, I might be wrong. Thankfully it won't be MY plane that has a failuremode experienced above.

Sprig

Quite the opposite, actually. You're in a very, very, VERY small minority, as the overwhelming number of finished RVs (and probably many other homebuilts) are using fast-ons with no problem.

I believe when the above poster was talking about the cheapo terminals loosening up he was referring to the CRIMP loosening, not the spade connecting mechanism. In fact, he could have been talking about ring terminals loosening up.

Take a fish scale and see how much you will need to pull a fast-on to separate a connection. Better to use logic and known, testable facts than anecdotal evidence. And by the way, there are several certified aircraft out there now using AMP PIDGs, not including many of the new LSAs our there using them.

Ok, having said (typed) all of that, you must build your airplane in whatever way makes you sleep better at night.

Also, I would recommend you complete a signature, as it would provide some insight/weight to your posts on the forum.

Best,

Davepar · #18 09-08-2006, 09:51 AM

I noticed a cool thing about the Fast-on connectors as I was using them yesterday. The spades have a hole in the middle of them and if you look really close at the terminals, they have a little catch that pops into that hole when properly installed. Belt and suspenders. No way it's coming loose in flight.

jcoloccia · #19 09-08-2006, 10:13 AM

Triple ditto....they aren't coming off and they grip tight enough to make a superb electrical connection. The ONLY thing I don't like about using them is if you're not careful in laying out your wiring on the terminal block, it can be easy to short things out by accident when working on them. I personally like to lay them out so the positive terminals are not too close to the grounds.

Then again I've worked on plenty where everything is right next to each other and never had a problem. I guess that's why I always disconnect the battery first

Guy Prevost · #20 09-08-2006, 11:01 AM

Let's do a quick analysis.

1. Let's assume that it takes 15 lbs force to remove a fast-on connector (it takes almost twice that). 15 lbf = 66.7N

2. Let's assume that the connector and the bit of unsupported wire after it have a mass of 100g. (Again very conservative--here on this planet that's almost .25 lbs of unsupported wire and terminal!)

3. Assuming we're not approaching the speed of light, F=m*a. Solving for acceleration (a), we have an acceleration required for removal of the Fast-On connector of 66.7N / 0.1kg=667 m/s^2, or 68.1 g's! Another thing to consider is that the acceleration would have to be in the same direction as the axis of the tab in order to cause a spontaneous disconnection. If the acceleration happens at 45 degrees to the tab axis, it'll take 96 g's to disconnect. ((68g)/sin(45deg)).

We're all free not to use FastOn connectors, but I don't think our planes or bodies will survive a large enough acceleration to cause one to depart its tab.

G