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Old 06-30-2011, 07:00 PM   #21
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How often do you power junkies run at WOT?

IMO, there's a place for getting the last fraction of a watt out of the motor/batt combo, but crawling isn't it. I just think its funny hearing about the power loss when the only time I use WOT during a comp is to get the rig flipped back over. If the rig isn't upside down, I probably never go over 2/3 throttle.

I like the smaller wire just cause it's more flexible and easier to work with, and is easier make the wiring look decent. I run 16 from the esc to the dig switch, then 18 from there to each motor, no connectors anywere except for the battery/exc connection.
X2! I went from 12g wire to 16g wire with no noticeable difference. Possibly related to the way I drive but I see VERY LITTLE use for full throttle!
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Old 06-30-2011, 07:12 PM   #22
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Quote:
Originally Posted by Manning View Post
How often do you power junkies run at WOT?

IMO, there's a place for getting the last fraction of a watt out of the motor/batt combo, but crawling isn't it. I just think its funny hearing about the power loss when the only time I use WOT during a comp is to get the rig flipped back over. If the rig isn't upside down, I probably never go over 2/3 throttle.

I like the smaller wire just cause it's more flexible and easier to work with, and is easier make the wiring look decent. I run 16 from the esc to the dig switch, then 18 from there to each motor, no connectors anywere except for the battery/exc connection.
Jump gaps, pop ledges, digging, I pull full throttle quite often upright. It's more about binds also, which was where the battery comment came in, the difference between a 480 30C and a 850 45C (or better) can be the difference between powering out of that tight spot or having LVC kick in from the voltage drop.

IMO if you run small wire and weak packs you might as well just run cheap machine wound motors. Why run a motor that can pull real power when you don't give it the power available to pull?
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Old 06-30-2011, 07:13 PM   #23
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EP- I have thought about doing threaded posts and plugs before. Not many people would appreciate a mechanical connection in this hobby. In robots they would love it.

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How often do you power junkies run at WOT?
Not very often, unless I am bashing around or running a scaler. It is normally when I need to jump a gap or pop through a section fast. It would certainly be used less often in a comp unless you are Gatekeeper.

I'm just a nut for thick wires though, I hate wire heat. My ebike has 4ga. Only needs 12ga considering the amp limit I run. It still runs cooler though, and my top speed and power is certainly increased.

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OK, devils advocate.......say you have a 4' diameter wire.....but the mating contact spot is .050", does this mean the connection can handle 1000amps????

Not.

It's contact area as well as wire area.

Figure the circumference of the bullet connector, that is all the amperage it can handle.

This I will argue with.
Indeed, the contact area is a choke point and can be the weakest link in the chain. The contact area from 13ga wire to bullet plug is at least as large as the thickness of the wire when butted and soldered properly (most of the solder cup can be mechanically touching wire before soldering), so in this sense we could consider the wire a choke more than the plug. At any rate the plug is of lower resistance than the wire it replaces, so with a proper mechanical and soldered connection we are still ahead in total conductivity. This was confirmed by my test a few posts back, and is not just an opinion of what it "probably" is.
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Old 06-30-2011, 07:30 PM   #24
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I'm just a nut for thick wires though, I hate wire heat.
This was confirmed by my test a few posts back, and is not just an opinion of what it "probably" is.
I hate wire heat as well.
Resistance with no load does not equate to "current capacity" at high loads.

Granted, I usually deal with 100KVA to 1200KVA UPS systems, a "Bit" () different than that our crawler applications.

Regardless, all the best stuff through 98% of a system can be killed by the 2%.

Gold plated connectors just means the connection won't change over time (measureably), it still comes down to cross section/contact area.

You & I can toss back & forth all night, it really won't matter in the referenced application.

Besides, it's posted on the Internet, so it must be true.....

I will likely NOT argue electric motor theory with you or Eddie......I know a bit, but know when I'm likely outclassed. (I have tons of class....most of it low though.....hehe)
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Old 06-30-2011, 08:01 PM   #25
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I love a good conversation about it, I wouldn't consider it an argument at all. Educate me, please!

Very good point about resistance not equating to current capacity. I'm more worried about voltage drop and heat. What are the next items down the chain for current capacity? Heat dissipation, duty cycle, thermal mass.....?


You lowbrow, hehehehe

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Old 06-30-2011, 08:10 PM   #26
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John only argues with me....ever one else he just has discussions.

Look at this way.....wire is like tits....bigger is better.....

I do promise you though, 1/4 throttle, 1/2 throttle or full throttle....voltage drop happens. The fact you are rarely at full throttle is irrelevant....smaller wire is making everything in the circuit work harder at all times.

I spent 10 years in competitive car audio.........even worked in the business. Voltage drop is a big deal.....trust me....same thing, quarter volume, half volume or at full....just the way it works.

Now whether most crawler guys can FEEL it, whole nother matter.......


Later EddieO

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I love a good conversation about it, I wouldn't consider it an argument at all. Educate me, please!

Very good point about resistance not equating to current capacity. What are the next items down the chain? Heat dissapation, duty cycle, thermal mass.....?


You lowbrow, hehehehe
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Old 06-30-2011, 08:16 PM   #27
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Hey, we agree on everything this time Maybe we can make em discussions now

Most people can't feel the difference between many system tweaks. Too much geardown to show subtle changes.

In fact, the only thing I can actually feel with fatter wire is more broken parts in my palms


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John only argues with me....ever one else he just has discussions.

Look at this way.....wire is like tits....bigger is better.....

I do promise you though, 1/4 throttle, 1/2 throttle or full throttle....voltage drop happens. The fact you are rarely at full throttle is irrelevant....smaller wire is making everything in the circuit work harder at all times.

I spent 10 years in competitive car audio.........even worked in the business. Voltage drop is a big deal.....trust me....same thing, quarter volume, half volume or at full....just the way it works.

Now whether most crawler guys can FEEL it, whole nother matter.......


Later EddieO
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Old 06-30-2011, 08:25 PM   #28
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Originally Posted by indiana mudcat View Post
Jump gaps, pop ledges, digging, I pull full throttle quite often upright. It's more about binds also, which was where the battery comment came in, the difference between a 480 30C and a 850 45C (or better) can be the difference between powering out of that tight spot or having LVC kick in from the voltage drop.

IMO if you run small wire and weak packs you might as well just run cheap machine wound motors. Why run a motor that can pull real power when you don't give it the power available to pull?
Then you should be running the biggest capacity and highest voltage (4s, 5s, etc) battery that will fit in your rig. As far as I know, there are no rules in competitive crawling regarding battery limits. Even 1.9 comp class is allowed 3s batteries now. And bashing, your budget is the only limit. So power up......

A larger capacity pack will have higher voltage under load than a smaller one. I'd speculate that the voltage difference between a 450 and 850 pack under full load is far greater than the voltage drop difference between 18 and 16 awg wire.

Just fyi, I run 850's. I wouldn't run anything smaller just because of smaller capacity pack's reduced voltage under load. I want power when it is necessary, but I'm practical about it.

Hey, when I was racing touring cars (where you are WOT the vast majority of the time), I worried about getting the last fraction of a watt. But for crawlers, it's kind of like trying to pick fly poop out of pepper. Why bother?
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Old 06-30-2011, 08:38 PM   #29
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tits....
In! thanks for the chance
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Old 06-30-2011, 08:42 PM   #30
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You've seen Mrs. Brood's boobs....so hush

Later EddieO

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In! thanks for the chance
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Old 06-30-2011, 09:09 PM   #31
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I am an electrical idiot so here is one for you guys who get this stuff much better than me. I am running mini mambas and I used the stock wires that came with the mini's. I did wind up using what I had to connect the motor leads. As a result I now have a smallish gauge wire coming out of the esc to a larger gauge wire going to the motor. Is this bad?
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Old 06-30-2011, 09:31 PM   #32
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umm, well if you are adding unneccesary solder to the circuit, then you are adding resistance....the smaller wire will also become a bottleneck in the circuit.

It's not very desirable and I would try to clean up your wiring if possible.....

Later EddieO
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Old 06-30-2011, 10:41 PM   #33
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Building a dual esc MOA in the size of bodiless chassis we are running these days is like trying to shove 10 lbs of crap in a 5 lb bag.

I use 16ga. wire in an effort to make it easier stuff the "bag". Many of the small lipos I use come with 16ga. or smaller wire anyway.

I don't miss whatever amount of power the smaller wire or batteries lose. I'll touch my truck before I fold the chassis in half trying to power it out of a crevace.

This thread is full of great information though. I was considering micro deans.... but not now
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Old 06-30-2011, 10:45 PM   #34
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Just a little info for those guys who don't know a little trick to make the mini deans safe. I only use them on the MRC for size but to keep everything safe, run to your local auto parts store and pick up some vacuum line caps. They fit perfect on the mini deans and keep everything safe!

I too run 16g just to save some room when possible. I'm not "good" enough to notice the difference, so no harm no foul lol.
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Old 06-30-2011, 10:53 PM   #35
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I liked it better when it switched to tits....

Later EddieO
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Old 07-01-2011, 12:45 AM   #36
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Thought I was learning something but now all I can think of is tits...
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Old 07-01-2011, 01:51 PM   #37
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Thought I was learning something but now all I can think of is tits...
Get your mind outta my gutter.......
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Old 07-01-2011, 02:16 PM   #38
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Originally Posted by SINister View Post
Thought I was learning something but now all I can think of is tits...

I would say this thread is no good without pictures but that would just get us in big trouble....


I run dual Mamba Micro Pros and they have 16ga wire connected to them so that is what I used to wire up mine and a buddy's XR. Now I don't know if this limits my Brood's power capacity but they work for me.

Hell I'm a rare one still running 2S batteries at this point. I had 5 new packs and wanted to use them. I will go 3S in the future though.
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Old 07-01-2011, 02:45 PM   #39
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I'm with EeePee... all black wiring but I'm a 13ga man. I still long for the days of hardwiring motor and battery. It made wiring jobs so nice and neat. Wiring always looked nice and there were never wires or plugs flopping all over the inside of a car. I hate using plugs.
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Old 07-01-2011, 06:28 PM   #40
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I'm with EeePee... all black wiring but I'm a 13ga man. I still long for the days of hardwiring motor and battery. It made wiring jobs so nice and neat. Wiring always looked nice and there were never wires or plugs flopping all over the inside of a car. I hate using plugs.
Shortly after I got started in 12th pan car racing, we had no connectors (Tamiya & crappy bullets were all that was around....).
We chopped down all wires so they fit + a tiny bit.
ESC was soldered direct to the motor (a bit of wire twisting to reduce EMI/RFI), packs had solder tabs on them to direct solder to the ESC.
We used medium silver content solder to reduce resistance. The RX was soldered into the ESC & steering servo.
This was for 27T "club stock" motors.

Did it help? Who knows.
Did I feel better? Absolutely!

Granted it shafted me last fall when my son & I started carpet racing, we needed transponders that used external power. All my connections were soldered so I had to drag out an old RX connector & solder it in to power the transponder.

In crawlers, going ~14ga wire is fine. If you have an ESC that has smaller ga wires on it, keep them really short to reduce losses.
About the only time we really load a rig is when we're in a bind. That is usually a good time to limit power....BEFORE you break stuff.
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