How to solder


'Click on all small pictures, to ZOOM'


Video: How to Solder a Dean Ultra Connector from Andrew Willetts


A key Element in Electric flight is knowing how to solder correctly, bad or broken connections could have deadly impact on the lifetime of your model, even hurt people, a bad connection means bad control.

If you are interested ONLY in soldering batteries and you already know how to solder, follow the link

Even though soldering is thought to be a simple process, it is possible to make many mistakes. If you are not experienced and have not learned correctly on how it is done, best case scenario, you won't succeed, worse case scenario, you will think you have succeeded, only to realize out in the field how really unsuccessful you really were.

The rules to start soldering are: 

  • Did you learn how to solder ?, if not and you think it is an "obvious, no need to learn anything", simply stop now. You may make too many mistakes. 
  • Do you have the correct material ? 

    - Solder 20-30 W. Could be nice to have a trigger to increase the power to much more, for instant soldering, when needed. On the other hand, many people recommend to use a pencil iron instead, about 30W-40W.
    - Solder 60% 40%
    - Place to hold the part you will want to solder
    - Place to put the iron, when not in your hand (little stands are sold very cheap, for this purpose)
    - Something appropriate to clean the iron when hot ?
    - Do you have a comfortable and safe space to do this ? (don't be behind a closed door...) 

  • Make sure your electricity infrastructure is able to support the wattage of your iron. Many people in this hobby tend to use millions of electric appliances, all connected to 1 plug in the wall. If your house is well secured, it will maximum cut the electricity in the house, if required. If the house is not, it might be dangerous. Just check. Another risk here is that the plug can handle a certain amount of wattage , but the extension cord you are using can't. Here, nothing will warn you or stop the current and this can heat the wire to dangerous levels. In all this, if you just do normal checks or ask someone who knows, everything should be just fine. Always remember rather safe than sorry.

There are all kinds of types of plugs, you may use in this hobby, here is just few of them

Basic equipment we will use now

Click on the picture to identify each bullet

  1. Cutter, for wires here
  2. Tape, to insulate parts not covered by the shrink, if any (if work well done, no need for this)
  3. Shrink, need to cut small parts for each part to protect
  4. Stand, that can hold parts or plugs to solder
  5. Don't know the name in English, but this is a pump, to use, in order to remove solder, if needed. Just heat the solder to remove, press the pump button, and the solder should be eaten by this pump. Redo as needed
  6. Parts to solder. Here, these are plugs
  7. Solder
  8. Wires used to connect the plugs. Need to cut the desire length
  9. Wire-stripper
  10. Iron holder, specifically needed when iron is hot
  11. Iron itself. This model is a 30 - 130 W Iron gun, where if you press the trigger, you push it to 130W
  12. Some kind of dry sponge, to clean the iron

Step by Step instructions

  1. Prepare the components you want to solder, make sure the parts to solder are clean and that you cut the appropriate amount of shrink

    Note on the second picture, that when you cut the wire, you need to turn the cut part, in order to get the result of the red wire. The Black wire here is not ready to be soldered


  1. Prepare your iron:
    - Clean the top part while cold
    - Let it heat
    - Clean it again while hot

    You can see here that some solder had to be removed from the iron
    From Ezone: ""Tin" the tip of the iron by sanding it clean before heating, then heat and apply some solder, tap the iron and wipe on a damp sponge to remove extra solder, the tip should have a nice thin coat of solder on it."
    Very important ! Make sure the sponge is wet before you clean the tip on it.


  1. Put some solder on the iron where the contact with the part you will connect, will occur

  1. Solder the Wire:
    To do this, apply the iron on the metallic part of the wire, and put the solder on not on the iron, but on another place on this metallic part, in order that when the metallic part will be hot enough, it will solder it.

    If you see that it is taking too long, and you did follow the precedent steps, you can help the heating reactions a little by giving a little contact to the iron, and immediately take back the solder to its initial position.

    This wire is now soldered

  1. Clean the iron again, while hot (That steps is needed, time to time, when you see your iron not clean enough, having some solder on it, or not melting the solder properly)
  1. Solder the plug that will host the wire:
    First, stick this plug in your holder, in order that it won't move, while you will work, with both your hands free
  1. Then, solder the plug that host the wire, to do this, apply the iron on the face of the plug you won't solder, to heat it, while at the same time, pressure the solder against the opposite side of the same plug in order to melt some solder onto it. Stop when you estimate that there is enough solder on the plug

  1. Add the shrink around the wire, as far away from the heating point as possible, so the shrink does not shrink in the wrong place
  1. Now that both parts have solder on them , put them in contact, then pressure, with a prepared hot iron (see number 2 above) until both will melt together, then remove the iron, maintaining the wire, in the melted solder from both the plug and and the wire. It will harden within seconds.

  1. The plug is now soldered to the wire. Look at the look of the connection, the color and shinning is saying it went well
  1. In case anything would go wrong and you would need to remove the solder, use this special pump, done for this
  1. Let's assume that both wires are connected to the plug, we now need to protect shortcuts, by adding some shrink.
    The Shrink will "shrink" using any heater. I use a hair dryer, 2000W, and it does the work fine.

  1. Put the wire, with the shrink, in front of the heater, and wait until it shrink. It is recommended to apply a pressure, towards the plug, while it shrinks, in help the shrink to cover all the metal. If you don't do this, it may happen that the shrink will not cover the part, just next to the plug and you will have to use later, insulated tape to cover this. Because of this, try to shrink first, the part, next to the plug (see 2nd picture) and continue to apply pressure towards the plug, while it will continue to shrink

  1. And this is it, you are done with this one and can start opening a soldering factory

Some people use some flux, to ease the soldering part. I don't recommend this at all because:

- You don't need it, the above works perfectly well
- Some flux will damage the plugs in a short term, they contain acids. Since you can't know each time which flux is good or not for each material, simply avoid it.
- Most modern soldering irons use coated tips. You must never file these. It destroys them.
- Some soldering guns (as opposed to standard irons) are not good for electronics (like ESCs).

Important note: On this specific plug, I took the pictures starting to solder the (-) pole of the plug as it was easier to see on pictures. In real life, the (+) pole should be soldered first, then the (-)

Also, visit the Novak Site