flag8r

I'm in the painful process of soldering extentions on 4 servos for a glider...having some difficulty working with such small servo wires. I'm able to pre-tin all of the wires, but then when I try to get them together it's always a mess and I end up with a huge glop of solder. I don't twist the two wires together, simply lay them on top of each other. I do have the helping hands tool to assist. I think the 70w iron is too hot for such small wires.

Any tips would be appreciated.

ByLoudDesign

It sounds like you got the job started right! Pre-tinning the wire is a surer way of making sure you have a good joint. When you go to join them sense you have pre-tinned them you will not need much solder on you tip and with 70W you should only nedd to touch it and you should see the solder wick into the space between them. If you tape one wire down at the edge of your table and then hold the solder iron in one and the other wire in the other hand then things will not more around so much!

GuitarPlayer

Why not buy the extensions?

flag8r

I would, but in the glider wings, you are feeding the servo wires through a small drinking size tube...plugs on the extensions wouldn't fit.

richg99

Why not bend the ends over (or twist them?) A mechanical connection, along with the soldered connection..would be better. A "hook" or "v" on each wire end should join up and make soldering a lot easier, and be better in the long run. Rich

Rodney

As long as you have tinned both wires first, you should not be having a problem. You do need a jig to get the two wires (after being tinned) to lay side by side just touching each other over about a 1/4 inch length. There is no need to make the joint mechanically strong before soldering as a butt joint is more than adequate in this application. Now just touch the iron to both wires at the same time and the solder already on the wires should flow together (usually no need to add more solder). Just quickly touch the hot iron to the two and as soon as you see the solder flow, get the iron off the joint. You are smart in soldering in extensions rather than using plug in extensions as the added connectors, especially if buried in the structure and not frequently exercised, will sooner or later develop a high impedance connection causing possible problems. With a little practice, you should do fine. You could get by with a smaller wattage iron but, properly done, your 70 watt should work fine. More poor solder joints are caused by using to small an iron than in using to large a one. The object being to heat the joint as quickly as possible and then remove the heat source as soon as the solder flows so the heat does not migrate away from the joint causing damage else where.

108buzz

My Feedback: (14)

This is one method I was taught in the Air Force. You want to pre-tin the wires, then with a small neddle nose plier bend the pre tined wires(Both)into a small hook. Then install your heat srink and hook the two wires together, solder, and heat srink. It iseasier and addes strength.

Rodney

I was also in the Air Force as a radar Tech and was taught nearly the same. However, after completing 4 years of electrical engineering and working in the aircraft/spacecraft industry for some 20+years and in reliability studies, have found that is not at all necessary, in fact not recommended to make a mechanical joint first. Nothing wrong if you want to do it that way, just wasted effort and contributes nothing to reliability over a proper solder joint. Of course, for ultimate reliability you would always prefer crimp connections to soldered ones. I have had many items I designed/built flying in the Mercury and Gemini project with no know failures. Also lots of Cruise Missile test equipment.

flag8r

As an update to my original question...what is the best way to tin the wires before i try to join them together? Previously I had been dipping them in flux first. Next do I apply solder to the iron and simply touch the iron to the wire? Or should I touch the iron to the wire while holding the unmelted solder to the wire?

TedMo

Interesting how many methods have been given to a simple soldering question. For me I twist them together, hold iron beneath twisted wire, hold rosen core solder on top of wire until it melts throughtout wire. really easy and perfect solder joint.

Etep

OK you young whippersnappers, stand by and listen up! I am 80 years old and soldered my first joint just before I ate my first breakfast. (That milk was sure good , Mom. Thank you !) - by the way, I am still building them and flying them (And upside down at that).

The easiest way to solder a lap joint is to be prepared with a few items :

1. Have a clean uncluttered bench.
2. A bottle of alcohol. (Preferably, in this case, non drinking type.)
3 Two friendly helpers each made of steel with copper alligator teeth.
4. A pair of good wire strippers with a wire cutter on the end: $4 ??
5. some 1/16" 60/40 soldering wire
6. Soldering Paste of non-acidic content as a flux is always nice to have around for things electrical.
7. If necessary, a good magnifying lens.
8. X pieces of heat shrink tubing. "X" being the number of joints you are going to make.
9. Get a soldering iron or gun. (A 40 watt or 70 watt iron would do fine.) I personally use a Weller 100/140 soldering gun with a get in /get out quick trigger finger.
10. A heat gun for the heat shrink sleeving.

Now young fella, if I haven't worn you out getting all this conglomeration together, lets solder ! (Unless you wanna take a little nappy-poo first??)

The fine art of soldering a lap joint :

1. Strip each wire end about 1/4 inch each.
2. Put each the wires into an alligator clip and just "Wet" the copper portion with flux.
3. Dip the soldering device into the soldering paste and thin coat solder on its tip.
4. Your soldering piece in one hand and solder in the other, approach the waiting bare stripped wire with enthusiasm and sureness of a true ace.
5. With a tad of solder melted on your soldering tool, approach the bare wire with both the solder and hot ended thing trying to touch all at once.
6. Now touch and "WALLA" you now have one fine piece of tinned wire waiting anxiously to be matted.! This is just too exciting !!
7. Assuming you are not too exhausted from this exciting bit of play, let us continue.
8. Please repeat step numbers 5 and 6 with the awaiting wire #2.
9. You have now created a situation wherein you have two expectant wires waiting to be mated in an event that shall lead them to be true conductors.
10. Slide the piece of heat shrink sleeving over one soldered wire and well back of the alligator clip that presently holds it. (This should prevent heating of the sleeving prematurely.)
11. Move the wires such that they are next to each other, parallel,metal to metal the full length and insulation at opposite ends of the individual wires.
12. A hint of rosen flux would be understandable at this point.
13. Try to contain yourself and repeat steps 5 and 6 once more.
14. Wet a "Q" tip with alcohol and wet clean the newly joined ones.
13. Slide the heat shink tubing in place and apply the heat gun to permanently seal your piece of art.

I hope you live a long, prosper and have all solder-free worries.

wolfy888

What Etep said! Listen, a good connection depends on the CLEANLINESS of the metal, so flux is always a good idea. Rosin-core solder is an absolute MUST for electronics work, as it cleans the joint as the LEAD and TIN bond to the COPPER. Does this make things clear? When dissimilar metals are brought into close proximity, they have a tendancy to produce electrolysis, which ultimately corrodes the copper, which is the softest one. Cleaning and sealing the solder joint will prevent this from happening. O.K.?

108buzz

My Feedback: (14)

This is what I hate.A dude asks a simply question and the rocket scientsits and the engineerscome out. I work with some of the best engineers inthe country and if youssk them a simple question and you get a novel.The guy is not building a rocket ship for cryin out loud! The guy justs wants to fly. Look dude, slide on heat shrink, tin the wires, and bend them into small hooks. Hook them together and applya small amout of solder. Slide the heat shrink over the jount, heat and put your glider together and GOFLY!</p>

GuitarPlayer

I disagree. The solder joint not only is not a physical bond it will be electrically stronger if the conductors are wound together then fluxed and soldered. If not there is no physical bond.

108buzz

My Feedback: (14)

"electrically stronger" LMAO!!!!!!!!!!!!!!!!!!!!!!!

108buzz

My Feedback: (14)

I'm sorry I find that funny!  What, we have electrons with bigger muscle than others LOL.  I know I know, still I find that statement funny.

teamtigerpaw

Etep Gives a good soldering 101. 108buzz gives the I know everything and I'm so funny class.

108buzz

My Feedback: (14)

Funny class?  I do not remmeber that class in college.  Hey, thats a good one.  Amarillo LOL!!!!  Nice and flat which makes for easy landings.

teamtigerpaw

Yep it's just one big runway. The dirt may be a little soft. but if you land WITH the plow lines the worst is a nose over. 108buzz being a air force vet, Thank you for your service.
Joe

nonstoprc

My Feedback: (90)

I have been using this small gadget to help hold two tinned wire ends overlap to each other. The a touch of the soldering gun tip will join the two nicely.

A tiny bit of flux helps both tinning and joining. Do need to wipe out the flux residue with a piece of soft paper.

GuitarPlayer

OK one more time. Soldering two tinned, unwound to each other, leads will not hold in a vibration enviroment. Electrically stronger is dumb down for better current carrier. Take a piece of solder and break it. Thats the strenght of your joint! Ask any electritian. LMAO!!!!!!!!!

nonstoprc

My Feedback: (90)

Maybe try it, and also fix the "vibration" problem? LOL.

Have been done this for my gas, glow and electric planes, and yet to find a soldering joint failure in 15 years.


Edit. Added a photo of the soldered servo wires on my AW extra 260 75cc. Heat shrink tubes (3 X 1/16" for each wire, plus 1/4" for the three) are used to provide insulation and protection.

GuitarPlayer

Why not create a joint that surpasses the conductor in both strength and conductivity? Takes less time and is easier to assemble and solder.

108buzz

My Feedback: (14)

Teamtigerpaw,  Thanks for the vet comment.  It is appreciated but more important is that all americans think of and never forget those who have paid the ultimate sacrifice.  For they are more important than I am.  If we forget them, we are forgetting history and we do not want to repeat what we have already paid dearly for.   Antway,  These posts have some good techniques and I hope the are helping flag8r in his quest of the soldering process.

GuitarPlayer

I gave him the simplest easiest joint to build. Just so happens it's also the best working one. Don't over-engineer this thing.