Originally Posted by gixer

The last bit makes perfect sense.
You'd get a slightly finer control on a 30a Esc than a 60a Esc, but it seems like the difference is less than most of us can actually notice.


I really don't understand the kv requirements though.
To be honest i think the mods have been patient with me so far for hi-jacking this thread though so i really don't want to push me luck as a noob.

So if anyone has any links i'll happily read away.
If not i do have 1 more question please.

I've read up on BLDC motors, i understand how the differ from brushed motor and i understand how they work.
I also understand that rock crawlers will be geared for better torque and less speed.

But if say i went say brushless in my nitro firestorm then surely it would need a motor with more current draw than a motor in my pro3, if the top speed target was the same?

Wouldn't classing motors in a power/speed context be more accurate say 4600kv at 16k rpm?


I'm really enjoying learning all this, so if my enthusiasm is getting the best of me please just direct me towards some good faq pages and i'll lap em up.



Cheers
Mark

Originally Posted by yeahbaby

I think your are misunderstanding the the term "Kv"
Here is an explanation of it out of Wikipedia:
The Kv rating of a design of brushless motor is the constant relating the motors unloaded RPM to the (peak, not RMS) voltage on the wires connected to the coils (the "back-EMF"). For example, a 5700 Kv motor, supplied with 11.1 volts, will run at a nominal 63270 rpm. By Lenz's law, a running motor will create a back-EMF proportional to the RPM. Most ESCs do not boost the battery voltage. Once a motor is spinning so fast that the back-EMF is at or above the battery voltage, it is impossible for those ESCs to "speed up" that motor, even with no load. Kv is the voltage constant (capital-K, subscript v), not to be confused with the kilovolt, whose symbol is kV (lower-case k, capital V)

The rating is quite simple really for every volt you get x amount of unloaded rpm i.e 6000Kv motor on 11.1 v = 66600 unloaded rpm.

Rock crawlers are not just geared slow but they have low Kv motors or high turn brushed motors, they are inherently slower turning motors on any given volt.

Your Firestorm would probably end up drawing more amps due to it being heavier, but it's not something you can just calculate, it's kind of the result of your experiment. You could use a 3900 Kv motor on it and end up drawing more amps on it's setup than on your tc running 6000Kv - this could be due to a more efficient drive train and lighter weight on the Tc

Current draw is not something that stays constant even in the same car setup, it's more when going up hill, riding in long grass, having tall gearing, having more weight, snagging drive shaft and so forth - it's the equivalent of fuel consumption in a gasoline car.

Not sure I understand where you coming from here:
Wouldn't classing motors in a power/speed context be more accurate say 4600kv at 16k rpm?

Originally Posted by beemerfan

I used the bullet connectors and shrink that came with the speed control as solder joints to extend my wires and then direct soldered them to the motor in my RS4 MT setup. The motor solder tabs are as good as any other brushless motor and should hold up just fine. I don't plan on removing the motor from the car much so it is really a non-issue. This way, no additional items were needed. The holes in the motor tabs made soldering neat and easy. I posted a couple photos to illustrate. The setup works very well.

Originally Posted by mcdogboy

Seen 2 V2s, none had any form of USB cable, nor software.

Originally Posted by sldmodels

I've got a hobbywing bl speedo, or at least it looks like one that I bought from a friend recently. I can't figure out how to set it up as it doesn't seem to have a setup button. It has what looks like could be a button, and the speedo beeps repeatedly when I've held the button before turning it on, but other than that, it doesn't seem like I can get it setup.

The big problem is that at the mo, I've got nothing, then I suddenly get a surge of power, as though there is a delay on the speedo. I'm going to get a better speedo at some point, but the person I bought this off waterproofed it really good, so it'll eventually end up in my wet car.

Anyone know what I might have and how to set it up? Anything to identify it has been removed.

Originally Posted by sldmodels

Allready tried that. There's no visible button for the setup on the speedo, there's no identifying marks anywhere on it. What I thought might have been the switch was a surface mounted capacitor that "broke" off the other day, and a friend of resoldered it for me. I'm not even sure it is an easy run, it might just look like one.