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Discussion Starter · #1 ·
Many racers are aware that there has been some controversy over the summer regarding ROAR spec motors. Questions were raised including what type of changes required re-approval and whether production motors continued to meet ROAR requirements. This controversy resulted in ROAR announcing on September 12th that they would begin spot checking spec wind motors to make certain that production motors continued to be in compliance with ROAR requirements. In a continuing development, ROAR announced on October 5th that they were suspending all new motor approvals while this spot check program was underway. As part of this program ROAR will also be clarifying approval standards. This leaves several motors, including the new Novak High RPM motors, in limbo while the suspension of approvals is in effect.

We have been in frequent contact with ROAR throughout this process and had hoped that a resolution to the controversy would occur prior to the start of the BRL season. With our first race in just a few days; this now is very unlikely. The BRL has relied upon the ROAR approval process for determining motor eligibility because ROAR is the US affiliate of IFMAR, the international sanctioning body for all RC racing. All motor manufacturers are familiar with ROAR / IFMAR requirements and motors intended for competition are built to those requirements. Creating unique requirements and approvals for motors for the BRL is simply impractical.

While we strongly support ROAR’s current efforts, we have a race series to run and have to decide how we are going to proceed until ROAR completes their process. We believe the motors of greatest interest to our racers are the Trinity D3.5, the new Novak High RPM motors and all recent Thunder Power motors which have been changed to have wider cooling slots but still retain the same part numbers.

We will allow all 3 of these motor designs in BRL competition while ROAR continues with its process. We will continue to rely on our database of motor resistance measurements for motor technical inspection at the races. Because we obviously don’t have a large amount of data on the new motors, we will rely on the laws of physics to set our minimum resistance for these motors. It is a reasonably straight forward process to determine the difference in stator length, convert that to a difference in wire length and then calculate the equivalent resistance for the length of wire removed by the shorter stator. We will then use that difference in resistance to set our minimum for our tech process.

We will continue our practice of not publishing our minimum for reasons we’ve posted a number of times in the past. However I will say that some of the numbers “advertised” for new motors aren’t possible using our meter, ROAR construction rules and our approach to adjusting our data as outlined above. On the other hand, every example of the new motors we have personally checked using our meter has passed using that approach.

Because of these circumstances and the need to develop a data base on the new motor designs, we will suspend our Organizer’s Claim Rule for the Lefthander RC 375 at ProlevelRC. We encourage racers with the new motor designs to bring their motors through tech and we will add them to our database. Motors below the minimum we’ve established won’t be allowed in competition and will simply be returned to the racer without any penalty.

This is an imperfect solution which will probably not satisfy everyone. But we think it is the most practical approach for us to take until ROAR completes their spot check and rule clarification process.
 

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Discussion Starter · #4 ·
The third paragraph from the bottom of the first post states that I won't publish that number. I've never published the tech number I've used in the past either. And I've explained the reasons for that a number of times.

In this case, one big reason is that unless your meter reads the same as mine publishing the number will be meaningless and simply create additional confusion. Guys with meters that read low will think their motors won't pass when they will. Guys with meters that read high will think their motors are okay when they might not be.
 

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The third paragraph from the bottom of the first post states that I won't publish that number. I've never published the tech number I've used in the past either. And I've explained the reasons for that a number of times.

In this case, one big reason is that unless your meter reads the same as mine publishing the number will be meaningless and simply create additional confusion. Guys with meters that read low will think their motors won't pass when they will. Guys with meters that read high will think their motors are okay when they might not be.
Chuck-
Do you share the database numbers you have with ROAR, TOUR and the MFG's (Novak, Trinity, TP etc.)? No real reason for the question, just wondering if they ask that of you so they can have the numbers that you are finding. I assume you have hundreds of motor numbers at this point.

Anyway good luck on the upcoming BRL season.
Thanks
Joel White
 

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Keep fighting the good fight Big Chuck. Sometimes it's hard to see the fog when you're stuck in the middle of it.....and there are a lot of people stuck in it right now. Here's to hoping the fun of competing and the enjoyment of driving an RC car returns to the forefront.

Win at all costs=lose at any price.

See ya soon.

dk
 

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Looks great to me. Keeping the number private is the best thing that can be done! I just hope that ROAR follows this trend with their new rule package but I am not sure they will be able to keep it from the manufactures of the motors. And if the manufactures know the number they will brag about theirs being the closest or lowest and tell people. No win situation for any of us when that happens.

Looking forward to the BRL in TN!

EA
 

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Discussion Starter · #10 ·
Chad, I can understand the uncertainty created by not knowing the "magic number" and whether you have a legal motor in your box or not.

While I am still not going to give the minimum number for the new motors I am willing to say how we've arrived at it. We've taken a couple of approaches:

1- Measured data from myself, Allan Arrington at TOUR and Mike Boylan

2 - Calculations. The new High RPM Novak stator stack is about 40 thousandths shorter than their standard stator. Thunder Power motors and the new D3.5 are about 20 thousandths shorter than the standard Novak. 20 AWG wire (the max allowed in a 17.5) has a resistance of .43125 milliohms per inch for 2 strands in parrallel as used in these motors. A stator 40 thousandths shorter than the red wire Novak's in our database would end up with a resistance 00.6 milliohms below those in the database based on this resistance and the shorter stator length. (Please note that these calculations were done with measurements accurate to the nearest thousandth. I only say "about" in this discussion because I don't want to get into a pissing contest with somone who's measurements differ from ours by a thousandth or two)

3 - Wire length comparisons. I've unwound more stators this summer than I ever thought I would. Using the length of wire on the various length stators it's pretty easy to do some additional calculations to arrive at what the resistance of the motor would be using the maximum allowable wire diameter per ROAR rules.

Amazingly enough all 3 of these approaches arrive at about the same number which is a maximum of 0.6 milliohms lower than the standard motors in our database.

So we're adjusting the minimum in our database by that number (00.6) for tech at the first race.

We will also be adding a couple of things at tech. We will be recording the temperature of the stator when we take the readings and the length of the stator stack. We will also factor in those figures when making the decision on whether to allow a motor or not.

Joel, if I had $5 for every e-mail Allan, Mike and I exchanged this summer on motor resistance alone I'd be a rich man. My data is shared with TOUR and the Snowbirds and they share their data with me. I haven't shared with ROAR or manufacturers to this point.
 

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Chad, I can understand the uncertainty created by not knowing the "magic number" and whether you have a legal motor in your box or not.

While I am still not going to give the minimum number for the new motors I am willing to say how we've arrived at it. We've taken a couple of approaches:

1- Measured data from myself, Allan Arrington at TOUR and Mike Boylan

2 - Calculations. The new High RPM Novak stator stack is about 40 thousandths shorter than their standard stator. Thunder Power motors and the new D3.5 are about 20 thousandths shorter than the standard Novak. 20 AWG wire (the max allowed in a 17.5) has a resistance of .43125 milliohms per inch for 2 strands in parrallel as used in these motors. A stator 40 thousandths shorter than the red wire Novak's in our database would end up with a resistance 00.6 milliohms below those in the database based on this resistance and the shorter stator length. (Please note that these calculations were done with measurements accurate to the nearest thousandth. I only say "about" in this discussion because I don't want to get into a pissing contest with somone who's measurements differ from ours by a thousandth or two)

3 - Wire length comparisons. I've unwound more stators this summer than I ever thought I would. Using the length of wire on the various length stators it's pretty easy to do some additional calculations to arrive at what the resistance of the motor would be using the maximum allowable wire diameter per ROAR rules.

Amazingly enough all 3 of these approaches arrive at about the same number which is a maximum of 0.6 milliohms lower than the standard motors in our database.

So we're adjusting the minimum in our database by that number (00.6) for tech at the first race.

We will also be adding a couple of things at tech. We will be recording the temperature of the stator when we take the readings and the length of the stator stack. We will also factor in those figures when making the decision on whether to allow a motor or not.

Joel, if I had $5 for every e-mail Allan, Mike and I exchanged this summer on motor resistance alone I'd be a rich man. My data is shared with TOUR and the Snowbirds and they share their data with me. I haven't shared with ROAR or manufacturers to this point.
chuck
thanks for the info and all the both of you do ,my question was geared more toward the motors that i will be racing against , not so much as how low can i get my motors through tech at
 

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Discussion Starter · #12 ·
I need to add another clarification to my post. While Novak High RPM 17.5 stators have been available through distribution for a while, I can not find evidence of early enough availability of High RPM 13.5 stators through normal distribution. So, following our rules on availability, the 13.5T Novak High RPM stator will not be allowed in our upcoming race at Prolevel RC. The 17.5T Novak High RPM stator will.

Sorry for the confusion. I guess I've been too focused on the 17.5 issues.
 

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Discussion Starter · #13 ·
An update for the KCM Race Cars 375 at The Gate.

We will be following the same motor rules and inspection criteria for this race as we did at the Lefthander RC 375 at Prolevel. In addition, the Novak 13.5 High RPM motors (PN3623) have now been available long enough to meet the availability rule and they will be allowed.

Finally, if your motor is still sealed from the Lefthander RC 375 you do not need to resubmit it for tech. However it is your responsibility to be sure the seal is still intact. If your motor is not sealed you will, at a minimum, have any of your runs prior to discovering it is not sealed disqualified.
 
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