Best solder for shortening cables? (PAS, Motor etc)

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Lovelock   10 W

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Best solder for shortening cables? (PAS, Motor etc)

Post by Lovelock » Jan 30 2019 4:18am

Hey,

New motor is being delivered next week and on of the issues I had on my last build was the extra length of wire I didn't need.

All of the cables; motor, PAS, display etc are going to be shortened to make for a nicer build.

I'm new to soldering, but watching some videos I don't think It'll be a problem.

However, is there a suggested solder to use for these cables? I could Google it but prefer actual thoughts from people who have used and done this.

Thanks. I'm from the UK, just going to be buying a soldering kit from Amazon with a two hand stand thing.

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Re: Best solder for shortening cables? (PAS, Motor etc)

Post by alfantastic » Jan 30 2019 4:36am

As a beginner to soldering, I would personally use a leaded 60/40 (60% tin, 40% lead) rosin core solder. It's easier to work with and a little more forgiving until you get the knack of soldering.

I personally use Stannol HS10 (60/40) rosin core solder (0.5mm)

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Re: Best solder for shortening cables? (PAS, Motor etc)

Post by Volt_Ampere » Jan 30 2019 9:15am

Do NOT use Lead Free solder. It's much harder to use. Also, never use plumbing solder or acid flux. You need a fairly high power iron to solder the heavy gauge wire we use. First make a good mechanical joint and then get it plenty hot when soldering. If the result isn't nice and shiny, you got a cold joint and you need to reheat and add more solder.

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Re: Best solder for shortening cables? (PAS, Motor etc)

Post by spinningmagnets » Jan 30 2019 9:34am

The small soldering irons with a "pencil tip" are used for adding or removing resistors or diodes (etc) on circuit boards. Many seem to be 40W.

I have had many soldering irons, but for ebike wire and connectors, the one I use the most is a cheap 100W unit I found in an art supply (the stained glass window building section), and it has a fat chisel tip. It works fast and confidently on wire as fat as 10-ga.

Copper is a good heat conductor, and as soon as a small tip touches the wire, the tip cools off too fast, but a fat tip has some thermal mass.

I have tried lead-free SAC305 (popular in industry), and all I can say about that is...when the government bans all lead-based solder, I will buy up a lifetime supply of 63/37, and even some 60/40. Having flux in the core of the solder is fine for what we do, and rosin works fine as a flux for what we do.

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Re: Best solder for shortening cables? (PAS, Motor etc)

Post by kcuf » Jan 30 2019 9:46am

soldering very easy to practice free scraps of comparable wire components abound


practice until full confidence of outcome before attempting important workpieces
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Re: Best solder for shortening cables? (PAS, Motor etc)

Post by flat tire » Jan 30 2019 4:07pm

Buy a tube of flux in addition even tho you're getting rosin core. Apply the flux liberally to all metal you want to add solder to in advance. It will make getting the solder to adhere to the surfaces you need it on extra easy. Sure flux core mostly does the same thing but the limited amount of flux can make it difficult for beginners.

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Re: Best solder for shortening cables? (PAS, Motor etc)

Post by docw009 » Jan 30 2019 9:06pm

Don't use silver solder. It's what Home Depot sells to please the anti-lead crowd. It requires a higher temperature iron. Probably needs a torch to melt properly.

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E-HP   100 kW

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Re: Best solder for shortening cables? (PAS, Motor etc)

Post by E-HP » Jan 30 2019 10:59pm

Lovelock wrote:
Jan 30 2019 4:18am


All of the cables; motor, PAS, display etc are going to be shortened to make for a nicer build.

However, is there a suggested solder to use for these cables?
I agree with the guidance above on the solder.

But to clarify, are you cutting and splicing the wires and cables, or soldering on new connectors? Either way a smaller iron will do, since for the big wires (phase and battery) it's probably better to cut then crimped on new connectors. The rest of the wires are small, so a smaller iron is easier to manage and control the amount of solder you're applying. For electronics, I like the adjustable models.

Remember to buy some shrink wrap.

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Re: Best solder for shortening cables? (PAS, Motor etc)

Post by Lovelock » Jan 31 2019 6:57am

E-HP wrote:
Jan 30 2019 10:59pm
Lovelock wrote:
Jan 30 2019 4:18am


All of the cables; motor, PAS, display etc are going to be shortened to make for a nicer build.

However, is there a suggested solder to use for these cables?
I agree with the guidance above on the solder.

But to clarify, are you cutting and splicing the wires and cables, or soldering on new connectors? Either way a smaller iron will do, since for the big wires (phase and battery) it's probably better to cut then crimped on new connectors. The rest of the wires are small, so a smaller iron is easier to manage and control the amount of solder you're applying. For electronics, I like the adjustable models.

Remember to buy some shrink wrap.
Thank you for all the responses!

My plan is to cut out a section of the wire and solder back together, without touching the original connector.

The power cables wont actually be cut, they are pretty short as it is.

I'll see what non lead free solder I can find, Amazon doesn't seem to have much (UK)

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Re: Best solder for shortening cables? (PAS, Motor etc)

Post by Volt_Ampere » Jan 31 2019 10:02am

Smaller signal wires are easy to solder - you don't need a super powerful iron. Use heatshrink to cover the connections - not tape. Do get good 60/40 or similar lead/tin solder with rosin core. Make good mechanical connection by twisting the conductors together before soldering.

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Re: Best solder for shortening cables? (PAS, Motor etc)

Post by izeman » Jan 31 2019 10:26am

The advise for 60/40 lead solder was given before, and i +1 this.
Also do yourself a favor an buy some BRAND solder. DON'T order solder from China. I did, and threw all of it away again. The good brands cost a bit more, but also have the stated ingredients and a good flux core. Soldering will be much more easy.
And the 100W soldering iron with A BIG tip is great for soldering phase wires and stuff.

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Re: Best solder for shortening cables? (PAS, Motor etc)

Post by spinningmagnets » Jan 31 2019 12:49pm

I agree with izeman. Brand name solder might cost twice as much as generic Chinese solder from aliexpress, but...it's still very cheap. Crappy solder is a pain and it wastes your time trying to get a good joint.

If you don't have a preference yet for a specific brand, try Kester (although I am sure there are other reliable brands)

https://www.amazon.com/d/Soldering-Prod ... ster+63+37

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Re: Best solder for shortening cables? (PAS, Motor etc)

Post by Lovelock » Jan 31 2019 2:46pm

spinningmagnets wrote:
Jan 31 2019 12:49pm
I agree with izeman. Brand name solder might cost twice as much as generic Chinese solder from aliexpress, but...it's still very cheap. Crappy solder is a pain and it wastes your time trying to get a good joint.

If you don't have a preference yet for a specific brand, try Kester (although I am sure there are other reliable brands)

https://www.amazon.com/d/Soldering-Prod ... ster+63+37
Is there a potential for a soldering iron to be TOO hot for smaller wires? The main ones I wan't to shorten are the motor 9 pin cable and the PAS. These both contain thin wires.

Also, any chance you could recommend a brand of solder on the amazon.co.uk site :lol:

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izeman   10 GW

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Re: Best solder for shortening cables? (PAS, Motor etc)

Post by izeman » Jan 31 2019 3:35pm

https://www.amazon.co.uk/Weller-40-25-E ... 1548966655

1mm thick. Works good for most application.

Yes. If a soldering iron is too hot the resin will burn off, and the tip will suffer. If you aren't soldering too often a non regulated soldering iron will do, but you get regulated ones with exachangeable tips quite cheap:

https://www.amazon.co.uk/Soldering-Iron ... ering+iron

This one looks like it has tips big enough to store some heat. A small tip will cool off too quick when it gets in contact with a thick wire. So imho the bigger tip is more important than wattage.

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Re: Best solder for shortening cables? (PAS, Motor etc)

Post by mark5 » Jan 31 2019 4:15pm

Lovelock wrote:
Jan 31 2019 2:46pm
Also, any chance you could recommend a brand of solder on the amazon.co.uk site :lol:
Looks like you'll have an easier time finding solder with lead in it on UK eBay than Amazon.

Also get a brass wire soldering iron tip cleaner like the example below. They work better than a wet sponge.
https://www.ebay.co.uk/itm/BT-Soldering ... 2128264649

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izeman   10 GW

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Re: Best solder for shortening cables? (PAS, Motor etc)

Post by izeman » Jan 31 2019 4:36pm

mark5 wrote:
Jan 31 2019 4:15pm
Also get a brass wire soldering iron tip cleaner like the example below. They work better than a wet sponge.
https://www.ebay.co.uk/itm/BT-Soldering ... 2128264649
Good hint. A wet sponge will destroy your tip in no time. Cooling it off all the time causes micro fractures. Those wire sponges are great. I use them for years now. And always remember: When you're done with soldering, clean your tip, and cover is completely with fresh solder and let it cool down. This solder will seal the tip and prevent it from corrosion.

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Re: Best solder for shortening cables? (PAS, Motor etc)

Post by fourbanger » Feb 15 2019 9:40pm

That right there is some good advice that I was previously completely ignorant of.

Thanks izeman.

+1 on staying away from cheap ebay solder. I want my $2.49 back.

Don't know why you need to source out your solder on amazon though; just pop into her majesty's radioshack or whatever have you. It's not particularly esoteric stuff.

Maybe a bit OT but what are people's take on soldering GUNS around here? I seemed to think that I didn't like them, then ended up using an old sears 100/140 a little while ago and really didn't mind it at all. Little bulky, maybe, but it's nice to have that kind of power and I like being able to put it down just about anywhere without worry of burning everything to the ground. Meh

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Re: Best solder for shortening cables? (PAS, Motor etc)

Post by amberwolf » Feb 15 2019 10:33pm

Depends on what you're soldering, and how.

The guns can take significant time to reach temperature, and don't have much thermal mass (and what they do have is out in the open with a lot of surface area to radiate the heat away rather than store it to conduct into the joint).

If you have to use it by holding it on the joint while pulling the trigger because of that, well, many things in electrical or electronic stuff will probably suffer from the prolonged heating effects.

Theyr'e also generally large and heavy, and I'd rather use a lightweight pencil type that I can have finer control over. :)

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Re: Best solder for shortening cables? (PAS, Motor etc)

Post by fourbanger » Feb 16 2019 12:58am

That seems like a fairly astute appraisal. Interesting point about thermal mass. I put together a battery pack a while back using a 100 watt soldering iron with a pretty sizable chisel tip and while it went alright I kind of felt like another 40 or so watts of heat would have been nice. Having said that, I can't help but feel I was still better off with the 100w iron than 140w gun...

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Re: Best solder for shortening cables? (PAS, Motor etc)

Post by izeman » Feb 16 2019 4:30am

This is my favorite soldering iron for up to AWG8. Found it on Ali. Note the big tip.

Image

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Re: Best solder for shortening cables? (PAS, Motor etc)

Post by electricwheels.de » Feb 16 2019 2:58pm

For signal wires 0.14mm² and 0.2mm² I would use 40/60 leaded electronics solder 0.7mm diameter.
Even with these small signal wire diameters, I use a medium sized soldering tip that I clean with metal wool.

Here some instructions on how to join a signal cable.
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