noob soldering questions

[feralaero]

I just installed the mild kit. MAN, this stuff is small! My nerves were too shot to fly after the install, but at least it works... sort of. I'm afraid I might have some bad solder joints and could use some advice.

1) What is the best way to handle the existing joints at the main power connections? Even at 850F I could not wick them up, so I ended up soldering over top of them (60/40 at 675F). I'm assuming this is a bad idea because the original joints wouldn't be melting at this temperature. I was able to melt them with direct contact at 800F, but couldn't find a way to remove them or solder a wire into them.

2) My motor is bogging significantly with mild pitch pumps. Is this likely due to #1, or could my batteries be tired? I was having the same problem with a new brushed motor.

[SYMAWD]

Do you have any solder on your iron's tip (did you tin it)? Rosin core solder? Straight up heat won't melt it, you need solder on the tip to transfer the heat.

[Nytflyer]

The existing solder is a little harder to melt then the soler you are using but this is not a problem. Don't try and wick any of the original solder away either it's not necessary. Get some flux!

http://www.radioshack.com/product/in...ductId=2049774

That container is darn near a lifetime supply but there are many others that work just fine as well. Take the wires that you are soldering onto the +ve and -ve pads and strip them clean. Dip the stripped ends in the flux. I like to toch the tip of the iron to the flux now just to melt it a little. Now tin the end of the wire. Now put a tiny dab of flux on the pads on the board. Take your tinned wire and hold it to one of the solder pads. Now get a little blob of solder on the end of your iron and touch it to wire. Should only take a second but the hot solder will melt the factory solder and create a nice joint. Good luck

[NCcraig]

The only time I run my soldering iron over 580 degrees is to tin motor leads or when soldering on battery connectors for my larger helis. A clean tip is a must and I hardly ever use flux. I only use it when I'm removing solder from a board with some 24 gauge wire dipped in flux as a desoldering braid. A good rosin core solder is really all you need.

[feralaero]

Thanks guys. My main concern was that I would need to remove any existing joints first, but it sounds like this isn't necessary. I'm basically using nytflyer's method already, except I have a liquid flux pen instead of flux paste (any concerns here?). Next time I will try NCcraig's minimalist approach.

The only other problem I had was getting good joints on the motor connections ($@*# wires don't want to stay put when I remove the iron), but I know this will come with practice. And yes, I have one of those third-hand contraptions. I have been using tweezers to hold the wires in place, but I probably need to use the second alligator clip instead.

Thanks again. I think I may have to con one of the EEs at work into a PCB soldering lesson

[Nytflyer]

It all really just boils down to practice. A decent soldering station and a clean tip as craig said is a must. When I first started soldering on these little boards I tried with my cheapo radio shack iron and it was a nightmare. As far as flux goes I never used to use it and I never had any problems. The flux just makes things so much easier. Your liguid flux pen should be fine.

[C-lyde]

As stated you don't need to remove the old solder. A cool trick that I've learned though if you want to remove the wire or anything with pins on the board. Tin your tip, then use it to melt the old solder. Once the solder is melted take a carbon fiber rod and push the wire or pin out of the board. Wicking up the remaining solder is now way easier.

[Fooferdoggie]

a good iron to start with is this guy the price can't be beat and it works well.

http://www.hobbyking.com/hobbyking/s...arehouse_.html

[feralaero]

I think I figured out why I wasn't able to remove the old solder (not that it matters): I am using a very fine tip (Weller ETU), which probably can't put out enough heat. I may try it with the larger ETA tip.

[NCcraig]

Originally Posted by feralaero

I think I figured out why I wasn't able to remove the old solder (not that it matters): I am using a very fine tip (Weller ETU), which probably can't put out enough heat. I may try it with the larger ETA tip.

The ETU is the tip I mostly use. It puts out plenty of heat. Just remember bigger and hotter is sometimes not a good thing especially with this small soldering.

[4712]

I'm using ET-O here with small stuff (I guess it's similar to the ETU). I recently have found an adapter for the ET tips (ET-LT), so I will try the LT-1S the next days...

[feralaero]

At this point I'm not sure whether I should try to resolder everything. Is it normal for the head speed to dip noticeably with moderate pitch pumps (let's say +- 1 ft vertically, twice per second)? Others seem to indicate that the governor is pretty solid. This is a mild kit, gov arm mode, with new stock eFlite 150 batteries (problem is worse with tired batteries).

[bmc76]

Originally Posted by feralaero

At this point I'm not sure whether I should try to resolder everything. Is it normal for the head speed to dip noticeably with moderate pitch pumps (let's say +- 1 ft vertically, twice per second)? Others seem to indicate that the governor is pretty solid. This is a mild kit, gov arm mode, with new stock eFlite 150 batteries (problem is worse with tired batteries).

The motor will bog a little with hard pitch pumps. Dylan suggests not running over 85% on your pitch. What %throttle are you setting? If you set it too high the governor won't have any room to increase head speed, I don't go over 78%.

[bmc76]

Originally Posted by feralaero

At this point I'm not sure whether I should try to resolder everything. Is it normal for the head speed to dip noticeably with moderate pitch pumps (let's say +- 1 ft vertically, twice per second)? Others seem to indicate that the governor is pretty solid. This is a mild kit, gov arm mode, with new stock eFlite 150 batteries (problem is worse with tired batteries).

Another thought, did you use your tx to switch to gov arm mode? Lets just say you were still in gov tx mode by mistake and had a v curve set on the throttle. The motor would respond very slowly to your stick input.

[feralaero]

I'm running a flat 72 throttle curve but will try dropping down the pitch to see if that helps. And I was mistaken about the mode; currently using the Astroid default of gov tx.