I am having a hard time finding a tolerance on inductance readings of the brushless motors. I was just wondering what was the rule at the Snowbirds? I guess how many points over and under the Inductance numbers listed on the ROAR site. Any help is appreciated. Thanks...

Due to the wide variance of inductance numbers from motor to motor, they changed the method to checking resistance on each pole. The problem here is none of the manufacturers have put numbers up for people to see yet.

...and I would NOT expect them too after the BEAT DOWN they took for providing numbers in the first place.

Too many factors in wire numbers.

A) The person WINDING the motors and how tight the wire is pulled
B) The Quality of the wire used -
C) The Diameter of the wire used - Is their a min/max wire diamter?
D) Heat - changes numbers
E) Since the OVAL world has REJECTED ROAR, why would/should ROAR care what the OVAL World does, and why would they produce numbers to help them?

The inductance numbers used for the NOVAK motors will NOT generally be the same on a TRINITY or SPEED PASSION or TEKIN motor.

53 was the number used @ the Birds and several other races. This was from the solder terminals to the end ring in the motor.

I'm not sure if that was 53 AVERAGE or 53 on the LOWEST pole.

The NOVAK 21.5 submitted to ROAR is listed as having a 52.7, and I've seen several below 52.

Pole to Pole (AB) (AC) (AC) original NOVAK number was a 140, and I've seen several much below that standard too. (132, 134) and I constantly hear about motors in the mid 120 range.

A 20.5 motor should be in the mid - high 40's, from terminal to ring.

The NEW Standard for resistance is measured in Milli Ohms. You can NOT test this with a standard digital multimeter that most people have. A "Milli Ohm" meter is EXPENSIVE. (HIGH $300.00 range for a CHEAP one - and over $2,000.00 for a 'GOOD' one)

Blah, blah, blah... :rolleyes:

So, does anyone have the answer? I assume Frank is talking for Novak's in the oval world most of us live in.

yeah i'll say lol...

novak and trinty at least. thats what most people are running at our track.

Turn 4 race track rules has a pretty good rating rule on their web page in the rules section

I agree on the manufacturer standpoint of not wanting to provide numbers due to the variances involved.

BUT, I believe it was not only the racers who abandoned ROAR but some of that blame must fall squarely on ROAR's shoulders as well.

ROAR fell way behind the tech as far as laying out the classes and now with the last Paved Oval Race and the attempt at the carpet Nats, they have left a VERY SOUR taste in the mouths of the oval racers.

I have seen it said, have said it myself, OVAL needs ROAR. ROAR has the ability to provide stability and structure but IMHO just seems unwilling to do it.

Why? Heck if I know, I tried.

i am not a big roar supporter ...BUT

from what i have read and been told..

the roar nats at greenville had a cut off date for entries...they had 4 pre paid entries...so roar was kind enough to extend the dead line another 2 weeks...4 more racers signed up in that 2 week window...

roar clearly could not invest any money on hopes and prayers that 60 more entries would show up for the event...so they had to pull the plug....

WE the racers did not sign up for the race...alot of guys said they were going..but never signed up...so roar pulled the plug..

roar cuts a check to the track for 1500.00 they needed so many pre registered racers in order to justify sending a team and cutting a check...again 8 entries was not enough..

the entry form clearly stated to pre register...we didn't so they pulled the plug...

and that was before the bogus 5 amp rule...

i can't blame roar for the lack of entries...you can say 80.00 was too high and i agree and tyhe 5 amp rule is bogus....but in the end the lack of entries did allan in...

things turned out just fine in the end for both parties...

dawn stated the fire at the enduro was to blame..yet that had nothing to do with charge rate or heating a lipo..it was freeze spray...lot's of mis information and knee jerking went on...live and learn i guess

and for the record...
novak posted inductance readings on there web site...they even showed how to check the inductance...they even told you what meter to buy with a part# and web site...

only problem is....novak could not produce motors that were withing there own set limits...every month the new motors read lower and lower and lower...

so they earned all the flaming and than some....but of course it's our fault...half dead meter batteries and humidty was to blame in the end,lol....very few companies will take the blame anymore..too easy to blame the end user...i mean quality control doesn't play a big factor in why one motor made in may 2008 would read 55 and two months later in june a new in package motor would read 45...nah must be a crappy 9 volt battery in the meter...yeah thats it!

I was just trying to figure out how we can tech motors at our track. If someone shows up considerably faster than everyone else, I want to make sure we are checking the right numbers. It is so hard to believe that I can never get solid answers on this topic. How are motors being teched at big races? There has to be a list somewhere. Primarily, at our track, Novak, Trinity and Tekin Motors show up. I am looking for 17.5, 13.5 and 21.5. It was so much easier to tech brushed motors.

I was just trying to figure out how we can tech motors at our track. If someone shows up considerably faster than everyone else, I want to make sure we are checking the right numbers. It is so hard to believe that I can never get solid answers on this topic. How are motors being teched at big races? There has to be a list somewhere. Primarily, at our track, Novak, Trinity and Tekin Motors show up. I am looking for 17.5, 13.5 and 21.5. It was so much easier to tech brushed motors.

Agreed! I still have the old specs, but those have been proven wrong...

I was just trying to figure out how we can tech motors at our track. If someone shows up considerably faster than everyone else, I want to make sure we are checking the right numbers. It is so hard to believe that I can never get solid answers on this topic. How are motors being teched at big races? There has to be a list somewhere. Primarily, at our track, Novak, Trinity and Tekin Motors show up. I am looking for 17.5, 13.5 and 21.5. It was so much easier to tech brushed motors.

As aggravating as it might be, have everyone bring their motors to tech and then check each one. If you keep a log of every motor (Brand, wind, actual inductance), at least you have something to go by if you think somone is cheating. I'd say if you find ten that are within a few points and one thats real low, then that motor has either been tampered with or it's just one of the "good ones."

Unfortuantely, due to the fact that Novak got thrown to the wolves when they had some motors turn up really low, I doubt you'll find any manufacturer that will give out any numbers.

single pole numbers (NOVAK MOTORS)

21.5 - 53
17.5 - 34.5
13.5 - 21.5

LET .1 OR .2 ON ONE POLE SLIDE AND SEND THE REST PACKING.

I think these are the numbers used at the birds and at the Nats.

Every meter is a little different so you have to use good judgment and common sense, everyone isn't going to be happy.

i'm sure mike boylan has numbers written down for over 300 motors and 20 different brands..if you email him he will give you an avg i'm sure. he has been doing our motors here in florida for awhile now.

i emailed Mike back and forth a few times and he hasn't gotten back to me. I know people are busy and don't want to be a pain in the ass so I tried this avenue.

hmm sorry mike won't devulge his info he collected..if i had the info i would send it over to ya asap. i will see him in a week i'll ask him than.

haha run what ya brung lol

single pole numbers (NOVAK MOTORS)

21.5 - 53
17.5 - 34.5
13.5 - 21.5

LET .1 OR .2 ON ONE POLE SLIDE AND SEND THE REST PACKING.

I think these are the numbers used at the birds and at the Nats.

Every meter is a little different so you have to use good judgment and common sense, everyone isn't going to be happy.

And the rotor(s) was checked as well....if you were tore down that is....:)

Carpet I got ya!! Thanks!

haha run what ya brung lol

we had a guy do that at a big race a few weeks back and boy did he ever! lol must of been running a 17.5 disguised as a 21.5 because his car sucked yet he pulled everyone by 6 feet every straight away! he refused tech so we will never know. left early that day never to show again.........

and from what i heard that wasn't the only time or track!

so for the average track wanting to tech brushless motors...what do we do? I honestly can't believe there is no real way to check to see if a motor is legal or not? In brushed motors there were machine wound and hand wound...is this true in brushless too?

so for the average track wanting to tech brushless motors...what do we do? I honestly can't believe there is no real way to check to see if a motor is legal or not? In brushed motors there were machine wound and hand wound...is this true in brushless too?

All of the Novak brushless motors have hand-wound stators. We check resistance at this stage of motor manufacture and affix a label to the finished stator.

You can check all Novak motors of a given wind for the resistance numbers on the stators. This is the most reliable method of checking our motors to guarantee a given wind.

this still does not answer my question either. When we go to check a given motor, novak, trinity, tekin, team orion, etc... is there a given number that we should look for?

SIMPLE ANSWER - NO

a little more complex answer would be this.

Currently there is no ORGANIZATION that has a required BLUE PRINTED Standardization of SPEC motors with a compliance range for specifications.

NOVAK was the first player in the game, and other mfg's always want to build what they see as a BETTER product - instead of building something in the same tolerence range, unless rules a set for and very clear.

Therefore due to mfg's differences, and the differences in the products and procedures used to build the motors, ther is virtually now way to compare numbers from ONE to the OTHER.

okay let me ask this....if you take say 5 novak 17.5 motors and check them, should they be all about the same? I kinda understand the difference between the brand names, a trinity motor will be different than a novak...am I on the right path?

T-Shirt Man - that is probably the best way to test, especially for local/club racing.

Find and build a database w/ the local racers motors, and find the HIGH and the LOW.

There are some numbers that have been used for the NOVAK motors -- and these are good ball park numbers, but proved to be somewhat inconsistant...and hard to define HOW MUCH difference in performance there is based on those "inductance" numbers alone.

can you tell a big difference in a 21.5 vs. a 13.5 vs. a 17.5...etc...?

yeah, it's a pretty good difference.

Let me see if I can find the posted numbers here....

duh! they are here on this forum...

Brian posted the single pole numbers

single pole numbers (NOVAK MOTORS)

21.5 - 53
17.5 - 34.5
13.5 - 21.5

Those were the basic numbers used. For my races I don't normally worry too much - but for special events I will be using a lower number for the 21.5 ( we're using 51.7 average of the three poles
)

yeah, it's a pretty good difference.

Let me see if I can find the posted numbers here....

duh! they are here on this forum...

Brian posted the single pole numbers

single pole numbers (NOVAK MOTORS)

21.5 - 53
17.5 - 34.5
13.5 - 21.5

Those were the basic numbers used. For my races I don't normally worry too much - but for special events I will be using a lower number for the 21.5 ( we're using 51.7 average of the three poles
)

why would you use lower number like 51.7 on a 21.5?
those numbers show for a 20.5 motor which at the birds there was a few there and could not be run
some of the 1st 21.5 motors were that low. if someone has 1 of those it is not legal at any big race unless the your meter reads really high.

Alan

A) because both Mike B and NOVAK said 52's are actually GOOD numbers now

B) because THOSE motors are out there in BIG numbers

C) because as long as I know what we've got - I don't have a problem like some people do.

D) my goal ISN'T to send people home with products they BOUGHT OVER THE COUNTER that have lower numbers

E) because INDUCTANCE is NOT the right way to TECH a motor

F) because I always GIVE a little more in MY rules than ANYONE else.

G) the numbers I was given as "BEING 20.5" was closer to 48.0 Not 51


RULES are a line drawn in the sand - 51.7 is the LINE I drew, so if YOU buy a MOTOR and it comes up LOWER THAN THAT...and you just spend 1,000 to get to the race...YOU SUPPORT Not being allowed to run a motor that you have NO CLUE how much actual performance gain (if any) there is.

I don't fall for that SMALL STUFF personally, oh and there are SEVERAL of the Newer GREEN RING motors that check LOW too!

now I am even more confused....?

so if I tech all the 17.5 motors at our track...and someone has a 13.5 motor in the mix I will be able to spot it according to the meter?

it should stick out like a sore thumb.... Each motor has it's own range, and each range is considerably lower than the higher wind motor.

T-Shirt Man

I wouldn't get involved in 'teching' the motors locally, personally.

it just adds to the time of a program - takes away a lot of the FUN of racing - and NOBODY can tell you what kind of performance GAIN if any - there is.

HOWEVER - YES as far as the motors go - the range of inductance between motors such as

13.5

17.5

21.5

is huge

Test enough motors, and you'll get a feel for them and what you are seeing...and it is NOT cut and dry like some would have you believe. The are no true MAGICAL numbers. Electronics just don't work that way unless you want the PRICE of these little toy car motors to get a LOT higher.

When you use an INDUCTANCE METER and hook the leads to

Solder Terminal A , B, or C on one side, and the RING in the front of the motor with the other lead (with the end bell OFF and the ROTOR out)

if it's a 13.5 wind motor you will get a number in the 20's

a 17.5 motor will give you a number in the mid 30's

a 21.5 motor in the low 50's

LOWER wind motors give LOWER numbers.

So a tightly wound motor, which will use slightly less wire will be on the LOWER end of the range, where a looser wound motor will be higher.

For example, I HAVE a 21.5 motor that was mis wound. It has ONE terminal that reads 48.2 , 52.7 and 55.6. The 48.2 pole is most likely a 20.5 pole, and the 55.6 is most likely a 22.5 pole. The winder most likely miscounted on one, and inadvertantly added it to the other. But the THREE POLE average for this motor is still a 52.16


21.5 - 53
17.5 - 34.5
13.5 - 21.5

LARGER events may have a need for TIGHTER tolerence - but WHY on earth would you do it for local club racing when 99% of the time - you are dealing with CLUB level racers who will NEVER see the difference in these numbers 'ON THE TRACK' where it counts.

Too many other things

Handling
Battery Voltage
Speed Control Settings
Gearing

all play a factor --

Now, if your concern is someone running a 13.5 motor in the 17.5 class - IT's VERY OBVIOUS in tech!

ding ding ding...we have a winner! That was the best explanation I have heard so far. That is what I was wondering about. GO FAST TURN LEFT! Thanks.

My little two bits:
Joe has been around a very loooonnnnggg time and puts on events that are at a professional level with just enough tolerance to be able to bend a little when needed. He's extremely knowlegable and has very high integrity. He's been able to find that balance that keeps R/C "FUN"!!! Thanks Joe for all the great years of self sacrifice and for being a true hero of the sport. OK, now I can get back off my soap box. Ron Burgess

:) Thanx RON! It's guys like YOU that I do it for!

T-Shirt Man

I wouldn't get involved in 'teching' the motors locally, personally.

it just adds to the time of a program - takes away a lot of the FUN of racing - and NOBODY can tell you what kind of performance GAIN if any - there is.

HOWEVER - YES as far as the motors go - the range of inductance between motors such as

13.5

17.5

21.5

is huge

Test enough motors, and you'll get a feel for them and what you are seeing...and it is NOT cut and dry like some would have you believe. The are no true MAGICAL numbers. Electronics just don't work that way unless you want the PRICE of these little toy car motors to get a LOT higher.

When you use an INDUCTANCE METER and hook the leads to

Solder Terminal A , B, or C on one side, and the RING in the front of the motor with the other lead (with the end bell OFF and the ROTOR out)

if it's a 13.5 wind motor you will get a number in the 20's

a 17.5 motor will give you a number in the mid 30's

a 21.5 motor in the low 50's

LOWER wind motors give LOWER numbers.

So a tightly wound motor, which will use slightly less wire will be on the LOWER end of the range, where a looser wound motor will be higher.

For example, I HAVE a 21.5 motor that was mis wound. It has ONE terminal that reads 48.2 , 52.7 and 55.6. The 48.2 pole is most likely a 20.5 pole, and the 55.6 is most likely a 22.5 pole. The winder most likely miscounted on one, and inadvertantly added it to the other. But the THREE POLE average for this motor is still a 52.16


21.5 - 53
17.5 - 34.5
13.5 - 21.5

LARGER events may have a need for TIGHTER tolerence - but WHY on earth would you do it for local club racing when 99% of the time - you are dealing with CLUB level racers who will NEVER see the difference in these numbers 'ON THE TRACK' where it counts.

Too many other things

Handling
Battery Voltage
Speed Control Settings
Gearing

all play a factor --

Now, if your concern is someone running a 13.5 motor in the 17.5 class - IT's VERY OBVIOUS in tech!

ok goodluck:thumbsup:

Allan Behler just teched tons of motors last week at the Strand .. Al can you post what you found for numbers both in spec and out of spec ...

ROCKET

...how many FUNNY Rotors were found in MOTORS that were not designed for?

(Not that I'm sure how much difference it makes when a TEKIN rotor is put in a NOVAK motor)

Rotor size - 12.32 mm vs 12.29 mm and slightly different in the bearing sizes... but look very similar at first glance

wow looking at the numbers I just got a brandnew 13.5 came today there are novak got the motor pole induc. At 26.6 26.6 and 26.7 way off from 21 Min .. Ooh well albie

albie,

if you got a NEW motor, those are NOT inductance numbers...they are MILLI OHM numbers. NOVAK Doesn't use INDUCTANCE numbers on their motors any longer

so I guess the question is what is Min max on acceptable 13.5 in mili ohms ??

WHAT A NIGHTMARE! Its almost funny at this point. =-( I guess motor tech is a thing of the past.

as far as i know, nothing funny was found and everybody got their motors teched.

GOOD on the Nothin Funny -- I know I had the rotor issue brought to my attention, and I've compared and measure and ID'd the other brand that was brought to my attention, and they are close... I don't know if there is a performance issue or not, but there is the issue of NOT mixing mfg's parts!

WHAT A NIGHTMARE! Its almost funny at this point. =-( I guess motor tech is a thing of the past.

Agreed. We're running "spec" motors, but there's no "spec" to go off of... :rolleyes:

Todd,

The problem is... the Manufactures didn't BUILD a 'SPEC' motor, they simply built a motor that was asked for (In the case of 17.5 and 21.5) by US, and our very SMALL market.

Before this should have EVER been considered NATIONALLY as any type of an OFFICIAL product for the rest of the OVAL WORLD, structured BLUE PRINTS should have been created.

I wasn't worried about it for OUR racing, we are small numbers...but both of those motors quickly gained popularity, so it's been a work in process at best.

I Keep hearing people blame MFG's for things... but to me, THEY BUILD a product... they couldn't care HOW it's used...as long as it's USED and PURCHASED it keeps them in business.

(Example: The ORION 3200 LIPO)

This was a battery that had been on the market for WELL over a year before WE looked at it. THEY didn't build it with OVAL RACING or SPEC RACING or really ANY racing in mind. It was just a product they marketed like 100's and 100's of other R/C products you can buy in a hobbyshop.

WE TESTED IT
WE LIKE IT
WE ADAPTED IT to our CLASS STRUCTURE
WE've STAYED with is (and the 3400..which is the SAME BATTERY)

But, because there was no NATIONAL RULES STRUCTURE...Flight Power, SMC, Thunder Power and others also built a 3200 mAh battery...but since there was NO "C" rating, and/or STYLE "Blue Prints" they created different and as many say SUPERIOR products.

DID that create better RACING?

IMHO - NO! I did make racers have to BUY even more stuff though..and now deal with more of the same old BATTLES of Product Superiority (WHICH SOME RACERS ACTUALLY ENJOY)

WE never know what will become POPULAR in the future. Things have a way of popping up and taking off, that NOBODY saw coming.

I will say this...

ONE CELL is NOT truely ONE CELL (multi-cells paralleled) NEEDS to have a BLUE PRINTED SPEC...and if this is NOT DONE before this becomes a major class...EXPECT Manufactures to create the same old crap with NEW more powerful stuff...that appears 2 weeks before a big race!~

MOTORS still need a BLUE PRINT SPEC with a MIN/MAX tolerence level on virtually every component.

WIRE SIZE, WIRE LENGTH, BEARING STYLE and SIZE, SHAFT DIMENSIONS, ROTOR DIAMETER, Sensor wiring, weight, size, length, etc.

if the proper BLUE PRINTS are created, it won't matter WHO'S product you are running, they will have to be within a tolerence level. (Does that mean they will all be EQUAL? Heck NO - motors are NEVER equal...)

well said.