Electrical connectors: where to use a mini, large, or Deans connector

[MadMax]

Strain relieving is an issue that's not well addressed by Deans connectors.

I strain relieve molex type connectors by applying 0.5" of heat shrink to individual conductors about 1.5" of large diameter shrink over about 0.4" of the tail end of the connector and 1.1" on the wire sticking out. The effect of this is to gradually stiffen the wire coming out of the connector so you don't get a tight radius bend right at the sheet metal connectors. Any area where you get a sharp transition in wire stiffness is a place where you'll get small radius bends which cause high strain on wires. Effective strain relief is a luxury you often don't get to apply in AEGs because of the small space in battery compartments so I usually put up with some wire fatigue.

Solder is really bad for developing an area of strain concentration. The wetted zone becomes very stiff, like a solid wire, and the dry braid leading to it is comparatively very flexible so you get significant stress concentration at solder junctions.

Again, there often isn't much that can be done to strain relieve wire connections in AEGs. One good trick is to apply tape tabs to batteries for you to pull on instead of yanking on wires to extricate batteries from stocks. For instance, I like to tear a 1" wide ribbon of gaffers tape or duck tape that's about 4"-5" long. Fold it in half to form a 0.75" tag in the middle (touch the adhesive together to form a 0.75" tab) and adhere the remaining tape to opposite sides of a stick pack. This provides a pull tab to pull a stick pack out of an M16 or AK stock so you don't have to pull on the wires.

[CDN_Stalker]

The connections I do on any Deans connectors are pretty solid, I use a decent length of good heat shrink that provides some strain relief, usually about 1/4" or more past the end of the insulation.

[roughshadow]

when ever I do a connection with soldier. I put a piece of 1/4 inch shrink on, and slide it to the end of the wire. Then a piece of half inch/. The 1/4 inch melts on there first at the solder junction. Then the half I have yet to brake a wire near or around the solder or shrink tubing. Its always near the middle.

I have done a lot of wiring, and could probably rewire an aeg real quick now that i know the wire specs. I am going to put it to the test. The wires in the famas are losing continuity. And yes I am switching it to deans its supposed be the saw for the team.

[Naglfar]

Someone mentioned that using anything bigger than 18AWG was pointless, I'd like to remind everyone that if you ran a thicker wire anywhere outside the mechbox, it WILL reduce the resistance.
All wires (except superconductors) have some amount of resistance, and if you do a series circuit of half 18AWG and half 14AWG it will most definitely have less resistance than a full 18AWG circuit.

Lastly, is it that much more expensive for a meter of wire larger than 18AWG?

[CDN_Stalker]

Wire resistance really only matters for long runs of wire, and the resistance is given in specs as an ohm or two per 1000ft. Hardly worth even considering wire resistance when dealing with less then a foot of wire in an AEG. Yes, ok, you are correct to a point, if (grabbing examples) you ran a foot of wire that has a resistance of 3.6ohms per 1000ft, and attached it to a foot of wire that has a resistance of 2.8ohms per 1000ft, you'd have a lower resistance wire. But it'd really only be in the matter of say 0.008 ohms difference, which won't do anything noticable in your gun.

Now, if you ran a foot of higher gauge wire, and had even a half inch of thinner wire gauge in there, the net resistance of the overall wire would be the same as that small piece of smaller wire (and it'll act like a fuse does). That's why it's pointless to buy higher AWG wire for an AEG, run several inches of it through your gun, then into the #18AWG wire going through the mechbox to the motor. The #18AWG is still there, the gun will operate the same as if the entire gun was wired for #18AWG. You CAN'T run bigger wire through the mechbox of an AEG.

Interesting fact, AEGs use a type of wire that is of similar specs as aviation wiring. Mil-spec aerospace wire is Teflon insulated (wears better, is water and solvent proof), etc. Aerospace wire also has more strands than say the same gauge of "lamp wire" (which tends to be of loose twist and form), therefore has a higher amperage capacity, in a smaller size and weight.

[Wulfey]

Any idea where the cheapest place to purchase the Deans, Large and Mini connectors in Canada is ?

-Stu

[roughshadow]

Originally Posted by Wulfey

Any idea where the cheapest place to purchase the Deans, Large and Mini connectors in Canada is ?

-Stu

your local hobby shop

I kid you not.

they are all used on rc cars

unless your buying in bulk then I dont know

[Mantelope]

If you're in the market for batteries too, you can just get a ton of connectors from www.cheapbatterypacks.com and not pay any extra shipping.

[Richter]

When it comes to strength and reliability in electrical connections, what I've seen and been told in the racing industry is that solder is out, and crimping is in.

I'm not talking about Canadian Tire crimpers and butt connectors, but more price ones (I've seen crimpers that sell for over $300). I was surprised when
I was first told about this, but apparently a good, proper sized crimp connection will outlast a solder connection.

This is probably a little overkill for airsoft, but I thought I'd mention it.

[LUTNIT]

deans connectors can cost $5-7/pair in hobby shops. I snag them off eBay in packs of 10 pair for usually $12-15. There are the cheaper knockoffs on eBay (their shiny red or black, the good ones are a dull red) and you need to look at the glare/reflections in the pics. Usually they come with heat shrink too.

I got my last pack from this seller, good ones:
http://search.ebay.ca/_W0QQsassZpower.focusQQhtZ-1

Shipped from Hong Kong, almost all of em are, takes a week or two.

[MadMax]

That's a good find Lutnit. They're genuine Deans then? Gold plated contacts which snugly push together?

[Trader 762]

Has anyone put together their own battery set with loose cells?

I have a friend I'm trying to get into airsoft, he was big into R/C cars so he's got the know how about the electronics. As he puts it, he likes to tear things apart and figure out how they work. Always good to know someone like that.

He also mentioned about putting together a charger and discharger, as he also puts it, simple electronics, its rocket science to me.

But hehe, the trading world is simple to me, but rocket science to him.

I have full trust in him for "working" on my stuff when I get it.

I figure, get good quality parts and he'll supply the labour.

[Renegade)]

Originally Posted by Trader 762

Has anyone put together their own battery set with loose cells?

I have made a 10.8V battery for my ICS M4 foregrip with all RC brand 1700 Nimh cells, worked decent enough, charged flawless with my Universal.

[LUTNIT]

Originally Posted by MadMax

That's a good find Lutnit. They're genuine Deans then? Gold plated contacts which snugly push together?

Yup nice shiny gold, I've accidentally bought lots of the cheap ones but know what to look for now.

Originally Posted by Trader 762

Has anyone put together their own battery set with loose cells?

I made the battery for my crane stock out of a large pack that I pulled apart, works fine, used clear packing tape instead of heat shrink to keep the sections of batteries from flexing as heatshrink makes it too thick to fit into the tubes in the crane stock.

[Syn]

I can't find a better thread to post this.

My deans connector 24k gold plated:
Electrical connection on 2 of the connectors I soldered months ago are coming apart. I am buying new solder tomorrow so I decided to google and find out if I needed a fancier solder for gold plated parts. Found this:

http://en.wikipedia.org/wiki/Gold_plating

Soldering issues

Soldering gold-plated parts can be tricky.
Gold is soluble in solder. Solder which contains more than 5% gold can become brittle. The joint surface is dull-looking.


Gold reacts with both tin and lead in their liquid state, forming brittle intermetallics. When eutectic 63% Sn - 37% Pb solder is used, no lead-gold compounds are formed, because gold preferentially reacts with tin, forming the AuSn4 compound. Particles of AuSn4 disperse in the solder matrix, forming preferential cleavage planes, significantly lowering the mechanical strength and therefore reliability of the resulting solder joints.


If the gold layer does not completely dissolve into the solder, then slow intermetallic reactions can proceed in the solid state as the tin and gold atoms cross-migrate. Intermetallics have poor electrical conductivity and low strength. The ongoing intermetallic reactions also cause Kirkendall voiding, leading to mechanical failure of the joint, similar to the degradation of gold-aluminum bonds known as purple plague.



A 2-3 µm layer of gold dissolves completely within one second during typical wave soldering conditions. [1] Layers of gold thinner than 0.5 µm (20 microinches) also dissolve completely into the solder, exposing the underlying metal (usually nickel) to the solder. Impurities in the nickel layer can prevent the solder from bonding to it. Electroless nickel plating contains phosphorus. Nickel with more than 8% phosphorus is not solderable. Electrodeposited nickel may contain nickel hydroxide. An acid bath is required to remove the passivation layer before applying the gold layer; improper cleaning leads to a nickel surface difficult to solder. A stronger flux can help, as it aids dissolving the oxide deposits. Carbon is another nickel contaminant that hinders solderability.


Also read that silver solder is better for soldering on plating:

http://www.bhavanimetals.com/Solder_...ore_Solder.htm


So far this is the quickest buying option for me
http://www.thesource.ca/estore/Produ...roduct=6400013

maybe second option???
http://cgi.ebay.ca/WBT-SILVER-SOLDER...QQcmdZViewItem
edit: ordered the WBT from ebay it is mostly tin >96% and some silver ~3.8%, no lead. Lets see how good it is.

Also found this link that kind of confirms the 60/40 I used before may not have been the best choice.
http://www3.towerhobbies.com/cgi-bin/wti0001p?&I=LXKX34

"Silver or Gold plating requires a special solder. Ordinary solder
causes a chemical reaction which will degrade the joint. Deans
Racing Solder is 2% silver with high activity ProFlux."

good cheap 3rd hand http://www.misbehavin-rc.com/pit-lan...-procedure.asp