3PDT Soldering tutoriel video

[JPGraphX]

Hi!

Anyone Here Could make a video of how to properly solder on 3pdt? I would like to see length of cut wire etc.. Thanks!

JP

[R.G.]

No video, but then it's not needed.

The fundamental law of soldering is that the joint to be made must have all parts clean (bright, shiny metal) and must be mechanically sound and hold itself in place before you apply solder.

Before you even try to start, get your soldering iron tip clean (bright, shiny metal), flux it, and heat until solder flows smoothly into a covering of mirror-bright molten solder. I find that I like a tip temperature of about 550F-650F for normal tin-lead soldering; but I have soldering iron that tells me temperature. If you have a choice, err on the side of a little too hot. There is a reason for that.

Strip enough wire insulation to allow you to make at least a half-turn through the opening of the switch pin. Better to strip enough to make a whole turn, then pre-bend the wire to a hook, insert the hook, and bend the remainder of the wire to make a full circle through the hole in the switch pin.

Orient the switch and wire so that the wire lies as you'd like it to lie in the finished joint.

Either apply a bit of liquid flux, or use rosin-flux-core solder. Have enough solder on the iron tip that you can see it just trivially indent when you press it against a wire, or a small "bead" of molten solder on the tip. There must be liquid solder on the tip where you press it against the parts to be heated. A dry, crusty/cruddy looking surface on the iron is just as hot, but transfers heat slowly. You do NOT want heat to go in slowly.

Apply heat to one side of the joint, and touch the solder to the other side of the joint. when the joint is hot enough to melt the solder on the side away from the iron, the solder will almost leap through the joint, flowing towards the heat.

When that happens, get the soldering iron and solder off the joint immediately. Either let it cool or blow on it to cool it faster. You want it to cool to a solid before the wire can shift around inside the cooling solder and crack the joint while it's pasty, between liquid and solid.

A video of this process is almost worthless, except for showing what a clean joint and clean, tinned tip look like, and perhaps a properly stripped and affixed wire looks like. That's because the whole process takes about 1-2 seconds and is over. The visible part looks like you move the iron tip to the joint, touch the joint, solder flows and the solder and iron are removed. The important part happens very, very quickly and is uneventful looking, as the liquid solder sucks itself through the spaces in the joint.

The reason you want a hot, clean iron is that heat flows through materials at a speed that depends on the mass and thermal conductivity of the material. It takes time for heat to travel along a conductor. Almost all solder joints are intended to be made and the heat removed before the conducted heat can get off into other stuff along the metal that can be ruined by heat. You can try this and learn about it by stripping a piece of wire about 2" long and holding one end while touching a soldering iron to the other end. How long does it take for you to feel the heat in your hand?

With a very hot soldering iron, the iron will bring the far end of the metal to soldering temperature very quickly, and solder-coat the hot end before your fingers even feel the heat. If you turn the iron down so it's so cool it barely melts solder itself, it will still get the hot end to soldering temperature eventually, but it takes so long that your fingers get burned before the wire gets to soldering temperature.

So for good soldering joints without damaging other stuff: get in quickly with high heat, make the joint fast, and then get out quickly before the heat can conduct to other places it should not be.

Education is always expensive. At the cheap prices of 3PDTs, buy a few extra that you *intend* to use up learning to do joints in them. It will be well worth the cost to get the actual experience into your brain.

[JPGraphX]

Hey thanks so much for that complete tutorial! Very helpful!!

[R.G.]

You're welcome.

One thing I forgot to mention is that a lot of good practice can be done with simply insulated wires. Strip about half an inch of insulation from two pieces of wire. Form one of the stripped ends into a complete loop. That's your fake "switch lug". Now form the other stripped end into the loop and try soldering. When this is so easy it's boring, then move on to your learner/disposable switches. Finally to the real thing you want to work.

If I had to guess, I'd say that the difficulty of making a good solder joint goes down by 10% with every good one you make.

The first one is 100% hard. Then 90%, then 81%, then 73%, then 66% then 60%, then 53, 48, 43, 38%. That's ten joints. A modest PCB will have 50 to 100 joints. If you're taking time to do it right, the 100th *good* joint is about .0026% as hard as the first one - that is, not hard at all. But you have to be taking the time to make them right as you go along. It gets automatic after a while, just like walking.

[tubegeek]

I can only add three things to RG's excellent tutorial. (I teach soldering on a daily basis, thanks to him among others.) Especially, his estimate of how fast the learning curve goes seems spot-on to me.

1. If you are soldering a large enough object (say, the large-ish "hot" lug inside a 1/4" plug) you will be able to see a fast shimmering change in the surface of the joint after you remove heat, as it cools. If the object is as large as this, you must wait for this transition back to solid before moving the work or allowing anything to move. You do NOT want your solder joint to move while it's hot, large or small, but larger joints take longer to cool. However, at least you can see it happen with a large joint. I generally don't want my students to blow on their solder joints because they don't have enough experience to know how to hold everything steady while they blow. (RG has enough experience - this should not be taken as me second-guessing him!)

I believe it's for this reason that standard advice is to make sure that there is a good mechanical connection before you solder - so nothing moves around - as much as for the other advantages of a solid mechanical connection.

2. Good work can sometimes be done with a crusty iron but it is much more difficult and certainly not worth the bother. Soldering is as much chemical as it is thermal. So a clean, shiny soldering iron is a must.

3. Heat transfer is what you need to be thinking about. Don't contact the work with the point of the tip like a writing instrument (except for very small joints.) Contact it with the side of the tip point, more like a brush.

3a. That is an important, sometimes overlooked reason why any stranded wire ought to be neatly, tightly twisted before tinning and soldering. The heat transfer is MUCH better in tightly twisted wire. There are other, more obvious, reasons.

GET IN GET LIQUID GET OUT!

[JPGraphX]

Thanks again! I'll definitely practice all of your tips tomorrow! I was not so bad at soldering but definitely underestimate the mechanical links before soldering..

[JPGraphX]

For assembly order, you insert dc, jack and 3pdt in the enclosure before soldering anything?

[tubegeek]

For assembly order, you insert dc, jack and 3pdt in the enclosure before soldering anything?

That's one way to do it but another idea is to start with those parts in holes in a piece of wood, get the connections started and laid out before you attach to the enclosure.

RG's site GEOFEX has some info on this - look at the top of the page for the link to the GEOFEX main page. Also here's another link to a set of construction photos that give a pretty good sequence of the steps you can take to get a nice result:

http://www.madbeanpedals.com/forum/index.php?topic=9039.0