I have built 2 for myself and did the soldering for 3 quads for friends.
I'm the most skilful.... LOL
All were prone to failure, some had spectacular fireworks some just emitted smoke some fell out of the sky, most did all 3. Faulty soldering.
After watching hours and hours of youtube videos and hours of practice I got better at soldering but still had problems soldering, I bought 5 different irons.. each one progressively dearer.
Made sure I had the correct solder, the correct flux, damp sponge.
Bought a low powered microscope. I'm sure on one ESC while soldering battery leads I would have been able to cook a pizza on the ESC.
Then by sheer luck i came across a video about tinning.
Everything fell into place and suddenly all the irons worked well.
Why doesn't anyone in soldering guides mention TINNING...
Can't solder properly without it.
This exercise has cost me hundreds of $$$ in the past 2 months replacing ESC's, FC's AND #$%@ing receivers.
I hope this helps others ;(

If you read Oscar guide on soldering, tinning is one thing you must do.

https://oscarliang.com/soldering-guide/

(24-Feb-2021, 08:29 AM)voodoo614 Wrote: If you read Oscar guide on soldering, tinning is one thing you must do.

https://oscarliang.com/soldering-guide/

Umm... yea, TINNING CONTACTS, i assume he is referring to wires and pads...
But no mention of tinning the iron.
I think pro's assume that its common knowledge. All the videos that I looked at never mentioned this, in fact once I was aware I started looking for videos on tinning a soldering iron.
Previous to this hobby I used to only use an iron to connect automotive wires, never used flux, never tinned the wires and cleaned the tip with a large steel wire brush... lol

May I suggest a GOOD quality iron.. I just bought a quality iron and it has made the world of difference with the quality of my work.... I love having shinny smooth (solder) balls...
The unit I bought I got from cyclonefpv.. $44 and it has a hot gun, so if you want to try your hand at component/chip replacement ur good to go...
Having good temp control with good tips.. “ bueno”

(24-Feb-2021, 11:10 AM)Titanv11 Wrote: Umm... yea, TINNING CONTACTS, i assume he is referring to wires and pads...
But no mention of tinning the iron.
I think pro's assume that its common knowledge. All the videos that I looked at never mentioned this, in fact once I was aware I started looking for videos on tinning a soldering iron.
Previous to this hobby I used to only use an iron to connect automotive wires, never used flux, never tinned the wires and cleaned the tip with a large steel wire brush... lol

You don't need to tin the iron if you tinned the pads. I actually keep my iron pretty clean. The only time I tin my iron is to try to tin a bare wire.

Most tips come pre tinned this day and age. You need to keep that first 1/4” or so clean. Should look like bright shiny metal. If the tip is dirty clean first with a wet sponge while iron is at temperature. 
Don’t drown the tip in water you need to keep the tip temperature up. If the tip starts to get black/ dirty that a sponge doesn’t work, use a tip cleaning Brillo pad, also do this while iron is to temperature. The Brillo’s used are brass looking in color and have no soap. If you keep the tip clean with a sponge the Brillo shouldn’t have to be used often if ever at all. If the Brillo doesn’t clean back to shiny it’s time to replace the tip. Bad tips will never make a good solder joint and most likely will just drag solder over everything. It’s good idea to put as much solder on the tip as you can before cutting power and let it cool with the blob of solder on tip. This is the best way to keep oxidation off while storing. During the time the iron is hot but not used keep a blob of solder on it, then wipe and continue soldering as needed. This will also cut down on the oxidation extending the life of the tip greatly.

I am confidently able to solder now but the tip deteriorate's rapidly i think temperature of iron is too high, normally run it at 400 deg cel, will have to check Oscar's link for correct temp range for different size pads.
But I've finally been able to fly a full day without drama's.. 6 batteries rotating on a charger... first time in 2 months without hiccups.

(25-Feb-2021, 07:39 AM)Titanv11 Wrote: I am confidently able to solder now but the tip deteriorate's rapidly i think temperature of iron is too high, normally run it at 400 deg cel, will have to check Oscar's link for correct temp range for different size pads.
But I've finally been able to fly a full day without drama's.. 6 batteries rotating on a charger... first time in 2 months without hiccups.  

If you follow the tips I laid out your tips should last a very long time. A higher temperature when solder grounds is helpful because of how big the ground trace is. I do 800F on the grounds and 700-750F for everything else. A higher temp allows you to get in and done quickly. The longer your heating up the same pad the more likely the pad will just come off the board. Best to solder as quickly as possible

Thanks Kevin... will try that.

400 deg cel is fine.

You literally want to be able to touch the joint and it is soldered. Anything over 1 second and you are either using too small a tip or not enough temp and as Kevin mentioned risk damaging pads or components.

The only caveat to that is the lipo to esc wire. That may take a bit more as it is so thick but quicker is better and btw is the only time I use extra flux. I dip the wire into the flux pot. I find the flux in the solder is more than adequate for pretty much everything else.

I always tin everything. Pad, wire and just as I go to join the wire to the pad a tiny touch of solder to the tip. The tip I clean before every joint.

I currently use a a bevelled tip approximately 2 or 3mm surface area for motor pads...
Is that ok?

(26-Feb-2021, 05:58 AM)Titanv11 Wrote: I currently use a a bevelled tip approximately 2 or 3mm surface area for motor pads...
Is that ok?

That size tip I use for the xt-60 pigtail. Usually I find a 1 mm conical tip best for small pads. Some people use just the larger bevel tip for everything. It really just boils down to what your comfortable using. There is no “ right” tip really but there is definitely a “ right” solder joint. Your looking for shiny solder joints, smooth edges. A flowed look. If pads look crusty, dull, sharp and uneven that’s not going to make a good electrical connection. That is what’s known as a cold solder joint. You don’t want those. There are a lot of examples of how the solder should look. It really is kinda an art.

I only use one of 3 tips for quad related work which are shown in the following post. The one on the left is the one I use most often and the second from the right gets used for the LiPo pigtail pads. I sometimes use the one second from the left for the ESC motor wire pads.

https://intofpv.com/t-first-quad-build-l...9#pid45079

(26-Feb-2021, 10:19 AM)SnowLeopardFPV Wrote: I only use one of 3 tips for quad related work which are shown in the following post. The one on the left is the one I use most often and the second from the right gets used for the LiPo pigtail pads. I sometimes use the one second from the left for the ESC motor wire pads.

https://intofpv.com/t-first-quad-build-l...9#pid45079

yep.. same one's I'm using now Glad I got something right.
Now I'm successfully building quads because of all the help from you all in this forum.
I'm 63 and the youngest in the group, the oldest is 73... lol
All soldering gets left to me.
I'm sure that eventually without your help we all would have given up
I can't thank you all enough.
Much appreciated.

[Tutorial] How to Solder - Principles, Technics, Etc.