Tekin Prez

Sensorless is more accurate and tracks the motor dynamically. Sensored is comparable to a brushed motor in that it is basically mechanical commutation. They have a ton of timing starting out and very little at top speed which is backwards.

Slotless sensorless motors are less expensive to build, but the circuitry and technology to drive them is much more difficult.

Given the same design and windings the Delta should be 1.73 times more power and KV. Both can be used to make a good motor. However the roar legal 5.5 wye motor is over 7000kv while a 5 turn sensorless delta is about 3500kv? Again backwards. We are not working with similar designs at all. One is all rpm and low torque and the other is high torque and low rpm. For these same reasons sensorless struggles with these designs when starting especially with the high turn slower motors. Sensors are needed to get them going, but we can drive them very nicely and accurately once rolling. That is why the RS runs in dual mode with a sensored start and a sensorless run.

Our RS and R1 non-pro controllers will run a 5 turn delta all day and even a 4 turn without much trouble…. Yet a 5.5 legal motor is a struggle due to the low torque and amount of power it takes to make it go. We are driving a Corvette in 3rd gear around town. By the time we get to a 3.5 motor the problem is exponentially worse for the controller and even our pro controllers barely hang on.

Given all of this we are making very nice legal slotted motors since that is what has been selected for sanctioned racing currently. Most expect the mod rules to be opened up to allow all technologies soon. Stock and super stock are the only areas we really need tight design rules to get comparable motors. Mod is rarely about the fastest motor in most applications.

Tekin Prez

Mister-T

http://www.dailymotion.com/video/x5d...00408-tr_sport

Truck with the Mamba max finished the race at the 3rd place. (truck number 2)
You can hardly see the difference of setup when running. And no noticiable cogging problem as well

Check the end of the movie there is some Racing Truck bashing , Racer can have some fun too ..

Rick Hohwart

oops! fixed

Tekin Prez

Last weekend at the Hank Perry 240 many of the 4wd 1/10 buggies in the Amain were running our 448 sensorless motors. Many of the 2wd buggies and trucks were running our 632 and 537 sensorless motors. I started with our sensored motors and took them out in favor of smooth feel of the sensorless slotless deltas for offroad. Different applications, different choices, everyone has a different opinion and they all go fast and have to be driven.

PDM

I do have the same opinion.

I believe slotless sensorless is the best technology, and they are smoooth, at least my Mambas are. I never tried yours, I believe they are new.

Not all the manufacturers have that technology yet I think.

For those that say sensorless doesn't give a good feeling, I can assure that never tried the right system. But get used to it because that will be the future.

It is true that Mambas are not ROAR legal, but that is a ROAR problem. Mambas are using today the technology that everybody will use in the future so it is a matter of changing the rules for better. With Dawn in the lead I am sure ROAR will do that move.

Rick Hohwart

Bold statement. ROAR's problem? nice try

PDM

Sorry Rick, I am not sure of what you understood from my words. I am european, english is not my first language, and I do not understand 100% what you mean.

I do understand however, that Roar brushless motor rules where done in a way to "protect" some manufacturers that where still understanding what brushless was. They where made to keep Hacker, Kontronik and others out of the races, because with the same sized motors these manufacturers where doing twice the power. But this you know better then me.

I do not see a way of ROAR keeping far of the technology for much longer...

Rick I do not want to argue, I am nobody, you are Rick Hohwart, known everywhere...these words are just my two cents, as you American say

lemansracer

First, what is cogging? (I have never heard of it.)

And what some good sensored brands? sensorless brands?

PDM

motor hesitate to run from stoped. Once they are running no problem.

Every brand on the market are good, if you buy the motor and Esc and use them acording to the manufacturer instructions.

If you want to start with brushless for legal races I would say to start with SpeedPassion. Good equipment and a very nice system to program the Esc.

Rick Hohwart

I apologize for my response. It took a long time for ROAR to legalize LiPo and BL and once they did, many criticize them for one thing or another. New technology will always appear but there has to be some point where you decide this is the way it is going to be.

It is like buying a computer. If you wait for the next development you will never buy one because there is always a new development coming.

The ROAR brushless motor rules were proposed by one manufacturer and it was those rules that were for the most part accepted and agreed upon by the current R/C car racing motor manufacturers. If the others had been as vocal trying to introduce brushless to R/C car racing, they may have been listened to. The rules left some out of the game. But there is no way that ROAR or any organization could create rules that would suit everyone at once. The point they chose was as good as any. And any manufacturer can create a motor for these classes.

Hacker has produced and submitted motors that are legal in ROAR classes. Others are free to do the same. The motors may not be as technologically advanced as possible, but the competion does not suffer as a result.

Randy_Pike

iTrader: (6)

Technology is always evloving. This is one of the main reasons why race rules are changed regularly.

I agree with Rick's statement about how the rules came about, he's right 100%. I don't have to like it, but that is how it was done at that point and time.

As the technology catches up and shows improvement the rules will once again change. Dawn is great and make no mistake about it, she looks into it all.

I think that this is one reason why Lipo's took as long as they did to become legal. Information was needed to make an educated decission.

I prefer the sensorless slotless motors in my offroad cars. They're very smooth and have more then enough power when the right motor is used in the right application. The cogging is gone and most of the high end esc's have full programming. The good ones have it all onboard.

The feel is opinionated at best. Some like it, some don't.

V12

iTrader: (1)

There are no 4T star motors, all of them are 7T deltas. There are some differences but basically the Orion and the GM motors are the same. Both are based on Feigao as Speedpassion, CS,.....

LRP also has a 4T what actually is a 7T delta.
I think the motors are labeled as 4T so people could compare them more easily with the usual star wound motors.

Potato

I have an idea. Why not set the modified motor rules to be open? Just set a maximum motor diameter (no minimum), maximum motor length (no minimum) and leave the winding type open. That way there's no politics involved and the rules don't favor any manufacturer. No need for speculation or constant back and forth arguments about the pros and cons of different configurations. Let the performance on the track decide which is best.

V12

iTrader: (1)

Good to hear that but GM is using this dual technology even longer. Of course as long as someone is using a sensor, but most GM drivers donīt think a sensor is needed. I just know from 4 cell racing where sensors are used.

geeunit1014

iTrader: (14)

thats just with the novak motor that has a crapload of timing. my 13.5 (and hopefully bill's 17.5) are smooth as ice

one advantage to SL nobody has mentioned is that you cant thermal in the middle of a run