Worried about reliability of soldered connections
#16
Tech Addict

before your race
check your connections pull on the wire if the wire comes off solder back on and put some more solder on it it should stick on
check your connections pull on the wire if the wire comes off solder back on and put some more solder on it it should stick on
#17

putting more solder on a cold joint won't actually help
in fact, the more glumpy solder on a cold joint, the harder it is to heat everything up to the proper temperature to get it to actually flow
Like I said in my mini-novel - the key is FLOW FLOW FLOW.
(the scuffing suggestion is a great one - can't believe I MISSED it. . .)
(Charlie - Dean's plugs only help for one connection. He still needs to solder wires TO the plugs (times two), TO the motor, TO the packs, TO the ESC. If he has cold joints on his packs, well, he's SOL there. . .and that sounds like one of the primary problems he's had. )
in fact, the more glumpy solder on a cold joint, the harder it is to heat everything up to the proper temperature to get it to actually flow
Like I said in my mini-novel - the key is FLOW FLOW FLOW.
(the scuffing suggestion is a great one - can't believe I MISSED it. . .)
(Charlie - Dean's plugs only help for one connection. He still needs to solder wires TO the plugs (times two), TO the motor, TO the packs, TO the ESC. If he has cold joints on his packs, well, he's SOL there. . .and that sounds like one of the primary problems he's had. )
#19
Tech Master
iTrader: (4)

Originally posted by stumper
I still cant believe im the only one who suggests tinning both parts before joining them together. IMHO its the easiest way to get a good solid solder joint.
I still cant believe im the only one who suggests tinning both parts before joining them together. IMHO its the easiest way to get a good solid solder joint.
#20

My battery bars break before my solder joints do - and I'm serious when I say this.
I crashed mega-hard during a qualifyer, tape broke, a battery bar broke, but all the joints were in tact
I crashed mega-hard during a qualifyer, tape broke, a battery bar broke, but all the joints were in tact

#21
Tech Regular

Considering I did diagnostic testing and soldering/replacement of components on boards for 6 years, tinning any wire and contact point was always a must in the industry. As far as what I worked on, most already had solder on the contact pads so tinning them was not needed. The best thing for a good joint is good tinning, proper heat (the longer and more times you heat the joint the more the flux is baked away and leads to a bad/cold solder joint), and use only enough solder to do the job. The wire should be fully joined and have no stray wires that can be broken off or bent. You use too much solder and get gobs on, just reclean with some solder wick and flux, and start over. Just make sure you don't keep the heat on for too long. You can damage the cells if they get too hot for an extended amount of time..
#22

Originally posted by imjonah
Solder and me do not seem to get along. Is there some gel, paste or liquid that is both conductive and adhesive that can be used as a replacement for solder.
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What I find hard to believe is that people depend on solder in situations where reliability is critical.
A. Why would I want to press a hot soldering iron up close to anything electronic or electric. Why am I risking my batteries or my motor by heating up part of them hot enough to melt solder.
B. Why in an situation where I know an object will be subject to high speed impacts and sever jolts, major g forces do I want to depend on the adhesive properties of solder to hold 2 pieces of metal together.
C. If I wrap a wire around a post, or I have some kind of connector like a deans plug or a bullet type electric plug, I can look at the connection I can tug on the wire, I can actually test the level of adhesion or security of the connection. With a soldered connection I am always afraid of pulling on the connection and I have no confidence in a visual inspection.
I have had an “old pro” who seems to be an expert a soldering help me. In the last month I have lost 3 races because of his expert soldering ( battery pack bar connecting two cells failed, a soldered motor connection came off and a soldered wire from a deans plug to a battery failed.) All three connections looked good seemed good worked for a number of races but ultimately failed. It is possible this guy is a hack and not really very good with solder, but I am wondering if the dependence on solder as an adhesive in RC racing is not the over all problem.
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My primary interest is reliability but I want to find a method which does not negatively effect the power of my car.
Solder and me do not seem to get along. Is there some gel, paste or liquid that is both conductive and adhesive that can be used as a replacement for solder.
------------------------------------------------------------------
What I find hard to believe is that people depend on solder in situations where reliability is critical.
A. Why would I want to press a hot soldering iron up close to anything electronic or electric. Why am I risking my batteries or my motor by heating up part of them hot enough to melt solder.
B. Why in an situation where I know an object will be subject to high speed impacts and sever jolts, major g forces do I want to depend on the adhesive properties of solder to hold 2 pieces of metal together.
C. If I wrap a wire around a post, or I have some kind of connector like a deans plug or a bullet type electric plug, I can look at the connection I can tug on the wire, I can actually test the level of adhesion or security of the connection. With a soldered connection I am always afraid of pulling on the connection and I have no confidence in a visual inspection.
I have had an “old pro” who seems to be an expert a soldering help me. In the last month I have lost 3 races because of his expert soldering ( battery pack bar connecting two cells failed, a soldered motor connection came off and a soldered wire from a deans plug to a battery failed.) All three connections looked good seemed good worked for a number of races but ultimately failed. It is possible this guy is a hack and not really very good with solder, but I am wondering if the dependence on solder as an adhesive in RC racing is not the over all problem.
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My primary interest is reliability but I want to find a method which does not negatively effect the power of my car.
I think you should stay well away from soldering irons, and anything pointy... lol:
#23

Originally posted by stumper
I still cant believe im the only one who suggests tinning both parts before joining them together. IMHO its the easiest way to get a good solid solder joint.
I still cant believe im the only one who suggests tinning both parts before joining them together. IMHO its the easiest way to get a good solid solder joint.
Adding it to my list. . .

#24

Thanks for the tips on soldering, excellent information.
but here is the problem. you make it sound so easy, cause it is easy for you.
Example: I tried to apply all the tips I recieved here to soldering a bad connection between a battery bar and a battery.
I used both a 35 watt pencil and then a 100 watt trigger type soldering iron/gun. I waited till they heated up melted some solder on the tip. I pressed the soldering iron against the battery bar, touched the solder to the backside of the battery bar their was not enough heat to melt the solder on the back side of the battery bar. likewise I pressed the soldering iron against the top of the battery and touched the solder to a point on the battery very clos to the contact point again not enough heat to melt solder. I frustration I cut off a small piece of solder put it between the battery bar pressed down hard on the top side of the battery with first one soldering iron then the other, the solder did not melt no matter how long I left the iron pressed against the battery bar. I had exactly the same experience trying to solder on to the copper surface of a motor.
Well something is wrong here obviously. If one of you had been there you probably would have an immediate answer.
Maybe I was not letting the irons get hot enough, maybe I was contacting the objects at the wrong point. Maybe I am using entirely wrong kind of solder. Maybe there is a way heat disapates on larger objects.
Thanks,
but here is the problem. you make it sound so easy, cause it is easy for you.
Example: I tried to apply all the tips I recieved here to soldering a bad connection between a battery bar and a battery.
I used both a 35 watt pencil and then a 100 watt trigger type soldering iron/gun. I waited till they heated up melted some solder on the tip. I pressed the soldering iron against the battery bar, touched the solder to the backside of the battery bar their was not enough heat to melt the solder on the back side of the battery bar. likewise I pressed the soldering iron against the top of the battery and touched the solder to a point on the battery very clos to the contact point again not enough heat to melt solder. I frustration I cut off a small piece of solder put it between the battery bar pressed down hard on the top side of the battery with first one soldering iron then the other, the solder did not melt no matter how long I left the iron pressed against the battery bar. I had exactly the same experience trying to solder on to the copper surface of a motor.
Well something is wrong here obviously. If one of you had been there you probably would have an immediate answer.
Maybe I was not letting the irons get hot enough, maybe I was contacting the objects at the wrong point. Maybe I am using entirely wrong kind of solder. Maybe there is a way heat disapates on larger objects.
Thanks,
#25
Tech Adept

Thats because your still using crap equpiment. Get either a Hakko, Weller, or Goot iron or station. I dont think Goot makes stations, but get a good one from Hakko or Weller. Trust me, it makes all the difference in the world. Dont even use a gun, that just plain not smart.
Stick with the stations. They dont nearly suffer from low line voltiage at the track like your iron will, and they are made much better, with being able to hold the heat at the tip in wind with no problems unlike your cheap iron.
If your iron is not able to melt the solder onto the bar within 2 seconds, the iron is not hot enough, and or is not powerfull enough. Dont get frustrated with crappy eqqpiment, get good quality stuff. It dosent matter what wattage those crappy radio shack irons are, they are too poorly made to work well enough for what you want it too do.
We all have been where you are. What did I do to fix it? Begged my parnets, and had them spend $100 at the LHS on a good weller station. Ever since then I have had my battery tape break in the middle of a race after a hard hit, but and every time the pack just gets dragged by the wire its connected to untill the car stops. Never have I had a wire brake off. And if a joint looks shoddy just tug on it. If it pops off then do it again untill it wont pop off. You probably will be a real good solder once you get the right equpiment. But not without the right equpiment.
Stick with the stations. They dont nearly suffer from low line voltiage at the track like your iron will, and they are made much better, with being able to hold the heat at the tip in wind with no problems unlike your cheap iron.
If your iron is not able to melt the solder onto the bar within 2 seconds, the iron is not hot enough, and or is not powerfull enough. Dont get frustrated with crappy eqqpiment, get good quality stuff. It dosent matter what wattage those crappy radio shack irons are, they are too poorly made to work well enough for what you want it too do.
We all have been where you are. What did I do to fix it? Begged my parnets, and had them spend $100 at the LHS on a good weller station. Ever since then I have had my battery tape break in the middle of a race after a hard hit, but and every time the pack just gets dragged by the wire its connected to untill the car stops. Never have I had a wire brake off. And if a joint looks shoddy just tug on it. If it pops off then do it again untill it wont pop off. You probably will be a real good solder once you get the right equpiment. But not without the right equpiment.
#26
Tech Addict
iTrader: (2)

Dont listen to that guy....You dont HAVE to have $100 iron to make good solder joints. I have a $6 towerhobbies 60 watt iron that works like a champ. It sounds like the iron isnt getting hot. Give it a couple minutes before you try to solder. You should be able to melt solder on the tip with ease before you can use it.
and one more thing. Use the thinner solder like the 1/32 stuff and not the 1/16. Its melts quicker and makes less of a mess.
and one more thing. Use the thinner solder like the 1/32 stuff and not the 1/16. Its melts quicker and makes less of a mess.
#28
Tech Master

Originally posted by stumper
Dont listen to that guy....You dont HAVE to have $100 iron to make good solder joints. I have a $6 towerhobbies 60 watt iron that works like a champ. It sounds like the iron isnt getting hot. Give it a couple minutes before you try to solder. You should be able to melt solder on the tip with ease before you can use it.
and one more thing. Use the thinner solder like the 1/32 stuff and not the 1/16. Its melts quicker and makes less of a mess.
Dont listen to that guy....You dont HAVE to have $100 iron to make good solder joints. I have a $6 towerhobbies 60 watt iron that works like a champ. It sounds like the iron isnt getting hot. Give it a couple minutes before you try to solder. You should be able to melt solder on the tip with ease before you can use it.
and one more thing. Use the thinner solder like the 1/32 stuff and not the 1/16. Its melts quicker and makes less of a mess.
#29

I also had a hobbyco $6 60wt iron, it worked fine for about a year then it fell to bits. I've now got a $20 40wt weller iron and it's great.
Even on half-wave it's hot enough to quickly melt solder. You don't need to spend a shat load of cash on an iron. Stations are very nice and if you have cash to burn then go for it, but a $20 weller iron will get the job done fine.


Last edited by fatdoggy; 05-21-2004 at 11:13 PM.
#30

True, & Jonah, I'd say the biggest problem for you is that the pencil iron you have is just too weak(& I bet it has a small tip, too), & the 100W gun just can't provide enough contact surface area to transfer heat effectively. The last thing you said is EXACTLY why you're having trouble, the bigger the objects you're connecting, the faster that material can dissipate heat, so to solder it properly you need both more heat & a big, broad tip to transfer that heat more efficiently, & something like those Weller 40W irons(that you can find for around $20) will work pretty well. In fact, I also have one of those as my backup for my modular Weller 50 watt one, & it's the surface area of the tip that allows it to heat up the batteries & bars fast enough to do the job right. Trust me, once you start using the right tools, it'll become MUCH easier, & you might even start to like doing it(I know I get some personal satisfaction from a nice, shiny & clean soldering job)....
