Wire sizes: any standard size? Mix & match sizes?

[Kobur]

Is there any standard size for wires between ESC and motor? Also is there any problem with having different sizes of wires from the motor than come off the ESC? I have some 10, 12 and 14 gauge wire. My old ESC (see signature line) appears to have 14 or 16 gauge wire.

Also, can solid copper wire be used for RC cars? I assume it is not commonly used because stranded wires are lots more flexible, but I'm not sure if that is really the reason.

I realize this seems a pretty basic question, but I am new to RC cars and still learning.

Thanks,

[Coelacanth]

It partly depends on the connectors you use. For example, I use EC3 connectors wherever possible. Those should accept wires from 14 to 10 GA. Thicker guage wires--8 GA and up--might be difficult to solder onto Deans connectors. I use 12 & 14 GA wires, either should be fine for restored vintage cars, even with up-to-date electrics installed.

[jwscab]

rule of thumb is....if you are using something more than a stock silver can motor, use the largest wire diameter that fits in the connectors and routes cleanest. More wires in the braid=more flexible. You don't want solid copper wires as they will eventually fatigue and stress crack, then break.

[Kobur]

It partly depends on the connectors you use. For example, I use EC3 connectors wherever possible. Those should accept wires from 14 to 10 GA. Thicker guage wires--8 GA and up--might be difficult to solder onto Deans connectors. I use 12 & 14 GA wires, either should be fine for restored vintage cars, even with up-to-date electrics installed.

rule of thumb is....if you are using something more than a stock silver can motor, use the largest wire diameter that fits in the connectors and routes cleanest. More wires in the braid=more flexible. You don't want solid copper wires as they will eventually fatigue and stress crack, then break.

So, does it cause any problems to have wires of differrent gauges connected to each other, like weird resistance effects? For instance, having an ESC with 14 gauge and then using 10 gauge from the connector to the motor? I have it in the back of my mind from something I was told a long time ago that there is some issue with that. I can't remember if if was just that it was a waste to use anything bigger or if there was some detrimental effect.

[Coelacanth]

Well, yes, if you're pushing current through a big, wide pipe and it's forced to enter through a much narrower pipe, it'll have a bottleneck effect, resistance-wise, I'd imagine. I don't think it's of utmost importance--for a runner, anyway--to have minor differences in wire guage, but for the racer looking for top performance, it *would* be important.

I think I've used different wires to connect the ESC to the motor wires, but maybe only 1 guage difference (i.e. from 14 GA to 12 GA). In general though, with the modern electrics, I don't mess with whatever it comes with; i.e. I don't de-solder and change wire size on motors and ESCs that already have a certain size soldered on. I leave the pre-soldered wires as they were intended by the manufacturer and simply make sure the connectors will match. With any decent connectors, you shouldn't have any resistance problems; Deans Ultras, EC3, EC5 (too big, overkill for a vintage car, IMHO) or whatever...all should work fine. But if you're running el-cheapo Tamiya-style connectors, upgrade them because they'll get hot and melt with today's electrics.

I also don't recommend the bullet-style connectors you find on many modern ESC's & batteries, because it's all too easy to connect them with reverse polarity. You won't have that problem with EC3's. I know a lot of people love Deans Ultras, but it *is* possible to accidentally short out adjacent off-gender connectors, even though they won't connect. I also dislike Deans because of how big a pain it is to solder thick round wires onto flat tabs in a plastic housing that melts when the tabs get heated by the soldering iron. I also don't like how they look when they're shrink-tubed, even ones that are done nicely look chintzy to me. If soldering for you, like me, is a part of the build that you don't look forward to with fun & excitement, consider EC3 connectors.

[jwscab]

as long as you aren't doing like 14 gauge to 20 gauge or something silly, it doesn't really matter. I would say for most cars and systems, anything from 14 gauge near stock to 10 gauge super low wind modified is perfectly fine. there is no issue making a splice from one gauge to another as long as the smaller wire can still safely handle the current. it just makes for a bulky ugly mess.

[mark in wi]

Using different size wire should, as said before, not hurt anything as long as you are not making large changes. I look at it like a weak link in a chain, the smallest wire will be the limiting factor on how much current the motor can get. If you ever get done running and the wires are hot then you would need to see about changing things to reduce resistance.