Broken flight controllers, losing FPV signal in-flight, and even whole quads falling out of the sky are all issues that can relate to bad soldering. In this article, we’ll talk about some important tips on how you can prevent this from happening and how to get good at soldering.
Great Quality Equipment for Good Soldering
Practicing soldering is actually not that hard. You’ll get better really fast. The most important aspect is to have good quality equipment. The following items I’d really recommend:
- Quality Iron with digital temperature settings
- Fine iron tip (B2)
- Good tin (preferred with lead core)
- Flux (flux-paste is better than liquid)
- Clamps for holding wires and components
Mostly I have my iron set around 380-420 degrees celsius. The small pads on flight controllers, receivers, and transmitters are better to do at 380 degrees celsius where the thicker motor – ESC connection is easier to do at 400 degrees. When soldering pigtails or other big wires or pads I even crank it up to 420 degrees celsius. With these high temperatures, you shouldn’t make contact with components for too long. The heat transfers and can damage certain parts of your FPV electronics.
Pre-tin wire and pads
Make sure you pre-tin the wires and pads you are going to solder. Do not pre-solder all of your pads before you are sure you are going to use them to save some weight and to keep your boards clean. Use some flux to make the tin bind easier to the pads and wire. Make sure it gets hot enough so the tin flows and covers the whole pad. You can add tin while heating the pad. If you do not get a nice shiny bulb you are probably not heating the pad and/or tin enough.
Connect the wire
When the wire sticks on the soldering pad it is fine right? Nope! At this point, the same rule as the previous step applies; you have to make it flow. When it flows you’ll see the wire can disappear in the tin. When it cools down you’ll have a clean shiny bulb and the wire is connected securely and making a perfect connection.
The most forgotten step, also by me but I actually had a few shorts that could have been prevented by cleaning the board. It could be possible some very small wires or tin drops are on the board that will cause shortages. Brushing the component with a toothbrush after you are finished soldering is never a bad idea!
Better Safe than Sorry
After you’ve got everything wired up and cleaned it’s time to check if there are no shorts on the component. You can measure this with a multimeter. If everything looks alright it is time to connect the battery. Having your fingers crossed while plugging in the battery for the first time is something I always do, but if you want to be even safer you can use a smoke stopper.