View Full Version : MOTOR Rating, Ranking, Tech, etc.


swtour
03-21-2009, 01:28 PM
With the Brushless Motors, we've seen using inductance as some type of measuring standard that has never before been done in R/C Racing.

What kind of variance numbers would we have seen with the old Brushed STOCK Armatures or 19t Arms?

What EXACTLY do these numbers mean...and HOW do we equate it to ON TRACK Performance / Horse Power?

Why are ALL mfg's not held to the SAME # range? After all, if a piece of wire is a KNOWN distance in length, wrapped the same number of times around it's core...should not ALL BRANDS of motors numbers be within a certain +/- tolerence? (If the design and materials were BLUE PRINTED they should)

Since NOVAK set the stage for Brushless Motor Racing we have seen a lot of changes already.


New Manufactures in the R/C Motor Game
New types of testing procedures (and tolerance numbers)
New types of dyno equipment
New ESC features - with added PERFORMANCE enhancementI personally hear a lot of talk about numbers on the B/L motors, and someone having a perceived advantage with them. But there are a TON of racers that have no idea what those numbers mean, or how to use them to their advantage.

This also goes for Rotor strength numbers.

A SMART racer never shows his true hand..escpecially if he's worked hard for an advantage...and numbers get HYPED and Sensationalized, and on the flip side of that...they get played down, if they have a number that was WAY out of line.

Recently, NOVAK quit offering Inductance Numbers in part because their appears to be a much larger variance going on, at least with their motors...for what ever reason. (Tightness of the wind...I don't know) , but before they did the had a pole to pole number of 140 listed, then a pole to ring number of 53.

Now, they are testing and labeling their motors with milli-ohm numbers on a tag under the purple ring.

Has anyone in the FIELD started looking at these numbers to see what kind of variance/tolerance there is?

The magical numbers used in ROAR as listed on their web site (inductance) is as follows

21.5
Novak 52.7
Tekin 49.5
Trinity 55.0

17.5

Ass/Reedy/LRP 38.5
Hacker 33.0
Losi 32.5
Novak 36.5
Orion 31.5
Speed Passion 34.5
Tekin 33.0
Trinity 34.0

So in the real world - how much can PERFORMANCE be expected by "The Numbers"

And how should the WORLD Standards be set?
















this info and questions were only asked, because I've been asked over the past couple weeks about some of this info by a handful of racers (Not my series racers) and since we are only affected by NOVAK numbers directly, I really have no clue where the other motors fall in by the numbers.

hankster
03-21-2009, 04:06 PM
:beatdeadhorse:Inductance can not be used to tech motors because it is meaningless when trying to use it to compare motors.

And how should the WORLD Standards be set?

As it has always been and is now, turns, wire size and length.

swtour
03-21-2009, 04:08 PM
Hank,

It AIN'T The HORSE of TECH that posed the question...it's the PERFORMANCE of the motors!

So in the real world - how much can PERFORMANCE be expected by "The Numbers"

hankster
03-21-2009, 04:09 PM
And there has always been a difference in performance of motors. Nothing is different now then it has always been.

Todd Putnam
03-21-2009, 05:37 PM
With the Brushless Motors, we've seen using inductance as some type of measuring standard that has never before been done in R/C Racing.



Inductance has been seen and used in R/C racing for decades. In fact, it was used to determine legality for the 10 turn limit On-Road brushed motors by ROAR in the early 2000's, and has been used by motor builders for years before that. :thumbsup:

hankster
03-21-2009, 06:15 PM
I would agree for motor builders it could be useful (I would think mainly for QC), but would be difficult for racers to use. Depending on the blank used, even with the same wind and wire size, the inductance can be vastly different. True?

swtour
03-21-2009, 07:48 PM
Todd,

I'm fully aware that builders used it. I know ol Big Jim used inductance...

I don't really think the way the questions were posed to me...that is what these guys were looking for.

Because RACERS are now worrying and concerning themselves with these numbers...a large number of racers have no idea what they mean..or equate to.

For instance, one guy hears the other guy talking..."I've got three motors, but MAN one of them sucks... It's only a 45.7 where all my others are 44.2" Yet NOBODY knows what that equates to in On-Track performance... but they are still worrying about 'Numbers'

Then you have the variance in the numbers that I cited that are approved ROAR numbers. Guys are asking WHY there is so much difference, and what does it mean.

(I think more than anything, we've got guys that are realizing they need to KNOW MORE..and they are looking for a starting point to figuring this stuff out)

NOTE (NOT Directed at anyone in this thread): Everybody isn't looking for a damn FIGHT over this stuff - some just want to know and learn it w/o a bunch of small ass answers that most of these threads turn in to.

RCThunder
03-21-2009, 11:24 PM
We saw the same driver tore down at the 'birds in two different races... both TQ / A-main runs and the motors were on average 2.2 points higher on inductance (same brand motor just a different motor)....

JW Housley
03-22-2009, 11:30 AM
We saw the same driver tore down at the 'birds in two different races... both TQ / A-main runs and the motors were on average 2.2 points higher on inductance (same brand motor just a different motor)....

Inductance is just a "SMALL" piece of the puzzle.......

JW Housley
03-22-2009, 11:32 AM
I would highly recommend NOT paying attention to numbers.......performance on the track is the only TRUE measurement....

Todd Putnam
03-22-2009, 12:42 PM
I would highly recommend NOT paying attention to numbers.......performance on the track is the only TRUE measurement....

Exaclty. Lower inductance cans and higher gauss rotors do not equate to more performance.

It is fine to concern yourself with the numbers, (corner weights, inductance and gauss numbers, etc; ) as long as it doesn't draw your focus away from the numbers that matters most - your lap times.

When I see people buying meters,scales, etc; before they own a stop watch, personal lap counter or a persoanl transponder (for the tracks who provide lap time for practice) I suggest that they spend their money more wisely. :thumbsup:

cneyedog
03-22-2009, 12:45 PM
Unfortunately TP, we all get caught up in the numbers game from time to time .......... but I remember one thing


but to qoute you "you cant fire a cannon from a canoe".......:thumbsup: ....... I think that advice means even more in brushless racing ......... some motors may have better numbers on a meter in the pits, it doesnt necessarily mean they run better on the track.

JW Housley
03-22-2009, 01:44 PM
Unfortunately TP, we all get caught up in the numbers game from time to time .......... but I remember one thing


but to qoute you "you cant fire a cannon from a canoe".......:thumbsup: ....... I think that advice means even more in brushless racing ......... some motors may have better numbers on a meter in the pits, it doesnt necessarily mean they run better on the track.

yep yep.....

samgkd
03-22-2009, 05:00 PM
I've been in the electronics field for over 50 years. I here people talking about inductance, resistance, amps, volts, voltage drop, etc and want simple answers. Well, sometimes there are no simple answers. Even if it was explained in technical terms, few people would understand what was said.

Some of the info is accurant, but just be careful and don't believe everything you see on this forum.

PS: Got a chuckle out of the lexan cover on the speed control.

KenBajdek
03-22-2009, 06:02 PM
Those numbers are part of the "mental masterbation" for racers.(I heard this from another racer and thought it was to funny to keep it to myself). Track performance is the real test. It is no different today that it was with brushed. I used to dyno all of my motors before race day to get the best numbers. Good numbers are great if race on a dyno. The old ways worked fine. Spec out the number of turns, wire gauge and the magnets, timing and all worked well with 2 or 3 motor mfgs.

casper60
03-23-2009, 12:26 AM
I agree that the numbers mean nothing. I test all my motors to simply gauge what I have in my box, not to see if my motor is better than the next guys motor. Out of all my motors, the one that perform the best are not the ones with the best numbers on them..

JW Housley
03-23-2009, 08:42 AM
Those numbers are part of the "mental masterbation" for racers....
hahahah...that's some funny shizzz!!!!!!:tongue: