Time For A Change

[Panther6834]

As the title clearly states, it's time for a change in the RC industry...specifically, to how RC motors are labeled, and marketed. As we all know, RC motors are currently labeled/marketed under their kV rating, or Turn rating...some manufacturers use 'kV', while others use 'Turn', but none (that I'm aware of) currently use both.

I am certain there are countless others who will agree with what I am about to propose...whether, or not, they are "vocal" about it. To anyone working in the RC industry and/or to those who know people working in the RC industry, please, please, please, pass this information along to those who have the ability to actually do something about this.

What I propose is this:

For all RC motors currently labeled/marketed under their 'kV rating', below the KV rating (on the box, and in all printed & online marketing material), in parentheses, the equivalent 'Turn' should also be listed. Likewise, for motors currently labeled/marketed under their 'Turn', the equivalent 'kV rating' should be listed. Additionally, below the equivalent kV/Turn rating, the 'wind' (ie. D, Y, etc) should be listed.

I, like many others, realize that there is not always a direct correlation between kV & Turn, thus it would be impossible to create an "industry standard"...but, it would be incredibly easy for every manufacturer to determine an equivalent number for each of their motors. As replacing motors (especially in RTR vehicles) is extremely common (otherwise, the aftermarket RC motor industry wouldn't even exist), this would greatly help those attempting to determine what motor(s) might best suit their needs. In regards to the Wind information, this can be greatly needed, as the Wind is also needed in determining where to set the timing (something the RC boating industry has been well-aware of for many years). For example, if you took two motors with the same kV rating...one with a 'D' Wind, and the other with a 'Y' Wind...the timing would need to be set differently on each in order for them to operate equivalently.

I'm certain there are probably a large number of people who could care less about having both pieces of information. For example, when it comes to racing, certain 'classes' only care about 'kV', or 'Turn'...but, for the far greater majority of Racers (ie. all the non-racers), having both pieces of information would be of considerable importance.

So, RC motor manufacturers, are you up for this change? It would not increase, in any way, manufacturing costs. Yes, it would take a little time in determining the additional pieces of information for each motor, but that "time" would easily equate to less than five minutes per motor designation. If a company makes a dozen different motors, that equates to one hour of time needed to determine this information. As for the printing on the boxes, that is a simple change that can be done in seconds for each box design, which could easily be applied during the next printing run of said boxes. Having previously worked in an industry where such changes did occasionally take place, I have firsthand experience/knowledge in knowing how incredibly little such a change would cost. Additionally, as this would be a one-time change, said cost (less than a few dollars per motor) to each manufacturer producing motors would be virtually non-existent.


~ More peace, love, and kindness would make the world a much better place

[AC49]

I don't know if this is actually possible. As much as I like the idea of it I think there are some issues at play. Now I could be wrong here, and I'll admit that my understanding of electric motors is limited.

I will start by saying that I really would like to see a KV rating of some kind on all motors. In some instances you can get brushed motors with an RPM rating at a specific voltage. Now you can take that rpm, divide by the number of volts and you get yourself a reasonable KV rating. Now I could be completely wrong here but I believe that you don't see a standard "RPM/volt" measurement on brushed motors because they are less linear in their RPM/volts compared to a more efficient brushless motor. That is why you'll often see the rpm measured at one specific voltage (like 6 volts). But again even with that information we can get a reasonable comparison between a brushed and brushless motor for speed.

Turns is a different story. Turns is actually a physical characteristic of the motor and both brushed and brushless motors have turns, and in both cases they are not comparable to each other. The number of turns inside the motor is kind of like comparing displacement of motors in cars. It's a physical characterisitc but it doesn't tell the full story. You can have a 300 horsepower honda civic, and a 300 horsepower truck and yet the motor sizes wouldm be vastly different and their characteristics would be too.

A lower turn generally will mean faster RPM because it means larger wires and more amperage moving through the motor. But a 27 turn motor may spin at the same speed (at 6 volts) as a brushless 17.5 turn. So it would be a really hard thing to standardize. This is why ESCs often place lower limits on the turns they can handle. Going too low at a specific voltage would cause too much amperage to be pulled through the ESC and you'd let the smoke out.

I do love the idea of a standard though. I think I would love to see a standard 7 volt rpm on all motors and then the turns.

That would be almost the same as Car makers giving you a 400hp 5.7L motor...


(I should add that my above response was not to educate the original poster as they seemed to aknowledge these limitations, just tried to outline my reason for thinking what I do and ultimately my conclusion on how to handle it with a standard that made sense)

[Panther6834]

I wasn't saying anything about a "standard". Obviously, one manufacturer's 13.5T motor might have a different kV than another manufacturer's 13.5T motor...but, both manufacturers could easily determine what the approximate kV of their own motor is.

Also, for any manufacturer's kV rated motor, they would, obviously, know how many turns are involved the the production of said motor, so that information could easily be given. They would also know the wind of their motor, which would help consumers in determining what the timing should be.

All I'm saying is, the manufacturers should, and could, provide this info. There's nothing about a "standard" in any of that...just 'info' they could provide. Say you're currently running the Traxxas VXL system, which most know it's 3500kV on a Slash/Rustler, but you're looking at a couple 4000kV motors...but, then, for a couple of other different brands, they're only listing their motors as to their turn. How do you determine what is similar to 4000kV?

Sure, their are charts you can search out that give approximate equivalencies as examples. But, if motor motors provided this info, it would not only save people a lot of time from having to try and figure these things out, but it could also potentially increase sales. For example, if you're looking for a 4000kV motor, and you find some motors that only list their Turns, how likely are you to buy from that brand? The truth is, probably not very likely. By providing more information, each manufacturer would increase the possibility of additional sales.


~ More peace, love, and kindness would make the world a much better place

[AC49]

I agree overall. I think that should be the "standard" to provide both Turns and some form of KV. A standard labeling practice would be at least a really good start. 100% agree.

I would actually love it if they had some standard specs, I'd like to see all motors rated at 6 volts (or 7) so that it was actually standardized and easily comparable.
You would walk into the store and ask for a 36,000 rpm motor and then you'd be really comparing apples to apples. And for at least some level of performance you'd be able to directly compare brushed and brushless motors in that regard.

Alas I'm sure it is only a pipe dream. lol