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Old 04-03-2008, 11:32 AM   #1
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Default Why bother with X Gauge wire on Brushless.

Title says it all. Why bother with 12-14 gauge wire to the brushless motor (not battery), when the wind wires inside the brushless motors may be half that size.

Am I missing something?
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Old 04-03-2008, 11:35 AM   #2
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Super-fat gauge wire helps guys make up for other "short comings".
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Old 04-03-2008, 11:42 AM   #3
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Old 04-03-2008, 11:50 AM   #4
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double, triple, and quad winds are still present in brushless motors, increasing the current draw. Just because you see skinny little wires in there dosn't mean its a single wind.
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Old 04-03-2008, 11:52 AM   #5
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I've wondered the same thing for years in regards to esc's. You've got guys swearing by 12g , but the the pcd board lead is far thinner. i don't care how condutive gold plating is, it just doesn't make sense to me.--Al
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Old 04-03-2008, 12:03 PM   #6
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Resistance in a series circuit is additive.
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Old 04-03-2008, 12:07 PM   #7
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Quote:
Originally Posted by RCHR View Post
double, triple, and quad winds are still present in brushless motors, increasing the current draw. Just because you see skinny little wires in there dosn't mean its a single wind.
Actually, I am speaking of such. The combined winds are still smaller gauge than what your putting towards it from the esc.
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Old 04-03-2008, 12:11 PM   #8
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Quote:
Originally Posted by big al View Post
I've wondered the same thing for years in regards to esc's. You've got guys swearing by 12g , but the the pcd board lead is far thinner. i don't care how condutive gold plating is, it just doesn't make sense to me.--Al
+1

There is a limit to increasing wire diameter. it is limited by the pc board, what many people overlook.

On the topic of wire guage and brushless motors, consider this. Look at the specification sheets of an esc. look at the amperage ratings. Do you notice they are per phase? this is complex, but basicly all the power is going through all 3 wires simultaniously. the amperage bieng drawn is not 50:50 per wire, but now 33:33:33. thus, less amperage is going through each wire. Now of course, the total current through each phase will fluctuate as it idles up and down, but you get the idea.

I believe you could do just fine running 16 guage with a higher turn BL. maybe 14 for the lowest turn BLM's. But those who want 12 guage, or larger for brushless, they will never need that guage wire, and are probably compensating for something else they lack... Lol!

Cheers!
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Old 04-03-2008, 12:17 PM   #9
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It sounds like you're all assuming that the resistance of the circuit is determined by the thinnest part... it doesn't work that way.
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Old 04-03-2008, 01:05 PM   #10
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Hi Trips, can you give a better explanation?
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Old 04-03-2008, 01:30 PM   #11
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Everything that causes resistance in a series circuit adds up. It sounds as though folks are thinking of the small wire in the motor or the small traces on the circuit board as "the bottleneck" in the circuit, so why have big wires elsewhere...

In an actual series electrical circuit, every source of resistance gets added together to determine the total resistance... so even though there are small wires in the motor, putting small wires between the speedo and that motor will result in more resistance than putting big wires there.

The power output of our motors is measured in watts... Watts can be calculated by current multiplied by voltage. To get more power given the same motor, anything you do to reduce resistance in the circuit increases current flow, increasing power. One reason why low turn mod motors make more power is that they use bigger wire for the windings, for less resistance thus more power (yes this a simplification, but it is close enough for this example) Given we want to make as much power as possible with any particular motor, one way is to reduce resistance anywhere else in the circuit... thus bigger wires.

I will say that there are sometimes advantages to using thinner wire... In my 1/12 scale cars I run 16 gauge wire because running 12 gauge would impede the flexibility of the pod and create handling difficulties. The difference in resistance between 12 gauge and the 16 gauge I use is tiny, so I'll take the very very slight loss of power to get better more consistent handling. If there was a big difference in resistance, I'd find a way to make the 12 gauge work. Given the ultra short wire runs in the car, the very slight difference in resistance between 12 ga and 16ga wire isn't something I can even feel.

I'll always use the largest wire practical for the situation... it's free power. Not much there, maybe not enough to even feel on the track, but if it's there I want it, kind of like keeping bearings clean and using very light oil... anything to reduce resistance (electrical OR rolling resistance) can't hurt.
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Old 04-03-2008, 02:06 PM   #12
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But one bad solder joint and it all goes to waste.

I mostly use 14Ga, on my caps 16Ga(8.5T, 10.5, 13.5), if i where to run a 4.5T and use 14Ga, would/will i have hotter components?
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Old 04-03-2008, 02:22 PM   #13
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I have tested 14 and 16g wire, it did not work out too well. all technical explinations aside, I will Never run anything smaller than 12g on my TC.

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Old 04-03-2008, 02:25 PM   #14
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we're still dumping 4500 mAH in five minutes. it doesn't matter what the components are, the wire loop is still passing enough current to empty a battery in a 5 minute heat (there are still only two leads from the battery).

incidentally, (in the vein of undetectable advantages) we're still:

matching cells to the .XXX volts
grading cells to the .XXX volts
using gauss meters on b/l motors

if you subscribe to the advantages of any of the above, you should be on board with heavy wire. dropping from 16ga to 14ga in circuit that uses 12" of wire will give you ~ 0.02V/cell advantage under mod sedan loads. i mean, c'mon. who runs 1.23's anymore, right?

these are usually the guys saying they can't get 'team issued' horsepower, meanwhile their ride is laden with speaker wire. afterall, 'you can't tell'. yet, somehow, that same +0.02 volts that the team guys have on their labels is always worth 10ft down the straight (or often a half second/lap).

simply awesome.
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Old 04-03-2008, 02:38 PM   #15
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I use 12guage just because the price is nearly Identical to the 16 guage wire... C'mon we all spend so much money on top of the line esc's and brushless motors with upgradable softfare interface and you are gonna cheap out on the wires...lol Might as well take the time to put the good wires even if the results are minimal.....
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