Need help soldering - RC-Monster Forums

speed demon · **Need help soldering -** 04.09.2008, 11:50 AM

I bought a new motor a few weeks ago and for the life of me I can't get the leads of the motor to solder. I want to do a simple butt solder to deans wire but the solder won't flow into the motor wire. It will flow great into the deans wire but thats it. I'm using flux core wire along with ample flux paste and still nothing. I also bought some 4mm bullit connectors but every time I put the wire in the socket filled with solder I can pull it right off with some force after it cools. What am I doing wrong? Is there some prep work on the wire I don't know about? The motor is a Himax and is just a backup but I still want it done right. Thanks.

Arct1k · 12:26 PM

Brushless motor? - Have the wires been shortened at all?

You may be stuck - some motor leads are extensions of motor windings and hence can't be shortened - they have an insulating laquer on them which is why the solder isn't flowing.

I think there are a couple of threads that you might be search for about using solvent to strip the insulator but you have to be careful as might wick into motor and cause a short.

A pic of the motor might be helpful. Rgds

JERRY2KONE · **Soldering. -** 04.09.2008, 01:04 PM

One of the things that I have found is that flux pastes are designed for different uses. You may have a flux paste that is not the best thing for your application. Is it an actual paste or a sort of jell? For me the jell flux works better for wire soldering. There are also different types of flux core solder. You have to use solder designed for wiring applications, not plumbers solder. Plus you have to get the both items that you are soldering hot enough to let the solder adhear to the metals. Try to get someone that you know who knows how to do this to show you the tricks to the trade

. It is easy once you get the hang of it, but there are little quirks to getting it done right

. Reading it from instructions is not the best way to learn

. Seeing someone else do it or watching a video helps greatly

. Good luck with that

.

speed demon · 04.09.2008, 01:30 PM

Yes I did shorten the leads and they come straight out of the housing(brushless) I did have brian at work give it a go for me and he has been an elctrian for 20+ years and he thought the wires were either burned up(new motor) or some type of coating. I do use flux paste and probably have plumbers wire. What is a good kind or brand? Is silver solder better? Lead no lead? I solder alot on my old mopar but nothing this critial. thanks for the quick replies.

One last thing if the wires have something on them which is not letting the solder flow could I use some acid(etching stuff) on the wires to get it off?

No pic but I might be able to get one in awhile.

01:56 PM

Quote:

Originally Posted by speed demon

Yes I did shorten the leads and they come straight out of the housing(brushless) I did have brian at work give it a go for me and he has been an elctrian for 20+ years and he thought the wires were either burned up(new motor) or some type of coating. I do use flux paste and probably have plumbers wire. What is a good kind or brand? Is silver solder better? Lead no lead? I solder alot on my old mopar but nothing this critial. thanks for the quick replies.

One last thing if the wires have something on them which is not letting the solder flow could I use some acid(etching stuff) on the wires to get it off?

No pic but I might be able to get one in awhile.

OOPS!!!!! On most brushless motors, the wires are just an extension of the winds inside the can. They are a specific length, and should not be shortened under any circumstances. They do indeed have a resin coating, excepting the very ends (last 1/4" or so) which are not coated so that they can be soldered to. I personally do not know of any way to remove that coating. You could possibly try muriatic acid, which you can purchase at lowes hardware for very cheap. I do not know for sure if it will have any affect on the coating though.

speed demon · 04.09.2008, 02:19 PM

Well live and learn I guess. Glad I only paid 30 bucks for it. Here is a pic and I'll see if some acid will work. The reason why I cut them was because I needed long leads. I desoldered the bullit connectors that came with it and tried to butt solder some extensions on to be able to reach my speed control. I thought I had it good but when I went to run the motor it was clogging very badly. I figured it was just not a good connection and that's when I bought the 4mm bullits and cut the wires.

Arct1k · 04.09.2008, 02:22 PM

You could try this:

http://www.bavaria-direct.co.za/models/faq.htm

How to strip the enamel coating off copper wire

Burn off the coating with a cigarette lighter or better still, a pencil torch. A heatsink will help avoid burning the wire back too far. It's like a thin alluminium clothes peg. Electronic supply stores may still have theml.
Burn the wires about 1cm back. Hold the bunch of wires flat over the edge of a table and rub with an ink rubber (eraser) to remove most of the remaining carbonated coating.

Use Bakers Fluid (from a hardware store, for soldering galv gutters etc,) on a cotton ear bud. This rips off any oxide when heated with a dry soldering iron tip.

Tin with solder.

speed demon · 04.10.2008, 12:04 AM

OK I burned off the coating the best I could and used pliers as a heat sink. Then some solder finally took hold and just did a simple butt joint. Threw the motor in my rustler and it had very very minimal clogging. Actually from first test drive the motor seemed to be faster but I'll have to wait until monday to find out for sould. Thanks for all the advice.

_paralyzed_ · 04.10.2008, 05:01 AM

I'm glad the amount of dancing in wooden shoes has gone down on your motor

fyi: it's cogging not clogging

What's_nitro? · 04.10.2008, 11:08 AM

paralyzed.

That wire enamel is nasty stuff. It's usually rated for 150*C or 200*C. Most high-end motors use the 200*C enamel.

Either way it takes serious heat to get rid of it (or a whole lot of patience with sand paper

). Luckily I had a butane torch when I shortened the wires on my 600XL. I'm glad to see it worked out for you, too.

Arct1k · 04.10.2008, 12:15 PM

Glad I could help...

speed demon · 04.10.2008, 12:30 PM

Clogging cogging sounds the same to me....but now I know. I used my little butane torch and an eraser to get the coating off. Was really surprised at how much the pliers soaked up the heat. I had some putty type heat sink at work for welding some small stuff but couldn't find it. Thanks again for all the help. Now where's the wooden shoes at