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Old 01-03-2008, 06:51 PM   #91
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NovakTwo - I couldn't read that SMALL PRINT

Sensor based motors are most often used in applications where the starting torque varies greatly or where a high initial torque is required, such as in a RC car.

If one looks at the industrial or aerospace applications of brushless motors, one would be hard pressed to find sensorless motors being used due to lack of starting torque and unreliable operation under noisy electrical conditions.

Sensored brushless ESC motor systems always know the position of the rotor. This is especially critical at low speed as well as at the start condition when there is no rotor movement. With the proper rotor position information, the ESC can apply power to the correct rotor phase combination.
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Old 01-03-2008, 06:55 PM   #92
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Originally Posted by ~McSmooth~ View Post
If Novak feels sensored motors are "far superior", then they should have little objection to allowing sensorless to compete in ROAR events. They would simply be able to dominate the competition, correct?

What better way to demonstrate their superiority than going head-to-head?
Novak has no objection to sensorless equipment running in all ROAR mod events and we will be supportive of any future changes to the ROAR mod BL rules.

We were in favor of less restrictive rules from the beginning, but ROAR wanted a rule for brushless motors that would allow for reliable motor tech---sensorless motors cannot be easily teched.

In the future, mod will be pretty much anything goes---let the better technology win. As it should be.
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Old 01-03-2008, 06:58 PM   #93
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Originally Posted by NovakTwo View Post
let the better technology win. As it should be.
Shouldn't this be: Let the better driver win? Brushless is "supposed" to even out the playing field a little.
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Old 01-03-2008, 07:02 PM   #94
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Shouldn't this be: Let the better driver win? Brushless is "supposed" to even out the playing field a little.
The goal of modified racing has always been to un-level the playing field....
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Old 01-03-2008, 07:11 PM   #95
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The Australian Nationals were won buy a sensorless ESC.
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Old 01-03-2008, 07:32 PM   #96
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What makes sensored motors easier to tech then sensorless?
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Old 01-03-2008, 07:49 PM   #97
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What makes sensored motors easier to tech then sensorless?
I don't have the answer, but I can post a response tomorrow. We have info on our website for how to tech the inductance of our motors. These are the guidelines race directors currently use for motor tech in the spec classes.

Motor Tech. How to Tech for Compliance

The current sensorless motors (Castle / Tekin) had not yet been designed when this original ROAR brushless motor rule was written.
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Old 01-03-2008, 08:43 PM   #98
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The reffered to test makes no difference if the motor is sensored or sensorless.

All that matters for that test is the rotor and the stator windings. The sensors have no effect!!!
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Old 01-03-2008, 09:29 PM   #99
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The current sensored motors on the market are wye wound, which others have already stated. Sensorless motors typically are delta wound, which to my knowledge works better because they allow the rotor to be more detectable than delta winds (an example being the cogging experienced when running Novak motors through a Mamba Max ESC).

I'd bet wye-wound motors are easier to "tech" than wye wound motors, which seems to be what NovakTwo was getting at.

I am a strong believer in sensorless technology. Never have I owned a sensored motor/ESC, nor do I plan to. The last time Novak got any of my money for anything power-related it was on an Explorer II that burned out quickly (although I will admit to having owned Novak receivers since then). Sensorless is just so much more versatile, and due to the lack of sensored offerings in the market, sensorless is MUCH better in my opinion.

Sensored ESCs can't run any motor larger than the HV-Maxx motor (unless you go old school and get an Aveox motor), and the HV-Maxx motor really is crap in light of the other motors out there. And the largest sensored ESC is the HV-Maxx, which can't stay cool even with the use of the included fan, is limited to 4s Lipo, and will even drain one 2s Lipo pack down faster than the other (making charging/balancing the 2x 2s packs as 4s a major pain).

So, sensorless is better, with the exception of racing (because ROAR is too lame to allow motor designs that were out way before Novak came out with its own motors).
Hopefully the R1 will enlighten those ignorant to sensorless technology...

Last edited by MetalMan; 01-05-2008 at 10:05 AM. Reason: swapped wye for delta, shown in bold
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Old 01-03-2008, 10:17 PM   #100
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Sorry mate but I believe you are incorrect.

The stator winding configuration star or delta is independent of senors as well the ESC.

The winding configurations are very similar to a 3 phase transformer and they both share the same relation ship of a factor of sqrt(3) equal to approx 1.73.

As an example 8.5 and 13.5T motors have the same winding configuration regardless of wether they are sensored or not so the test method on that link will be just as valid.

If the alternate winding configuration was used you can still use that method but the number would be all different as the number of turns would be different hence the length of the wire and its inductance would be different.
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Old 01-04-2008, 12:05 AM   #101
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I'd agree with Metalman. I would/have chosen sensorless every time because lets face it, Novaks brushless systems blow chunks. The HV Maxx is horrible. Why the hell does it come with a fan? Because the design isn't all that great and it runs hot in a vehical it was designed to drop in? Perhaps...
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Old 01-04-2008, 12:23 AM   #102
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Quote:
Originally Posted by frozenpod View Post
Sorry mate but I believe you are incorrect.

The stator winding configuration star or delta is independent of senors as well the ESC.

The winding configurations are very similar to a 3 phase transformer and they both share the same relation ship of a factor of sqrt(3) equal to approx 1.73.

As an example 8.5 and 13.5T motors have the same winding configuration regardless of wether they are sensored or not so the test method on that link will be just as valid.

If the alternate winding configuration was used you can still use that method but the number would be all different as the number of turns would be different hence the length of the wire and its inductance would be different.
It seems I must have misrepresented my thoughts in my post. I know winding type has nothing to do with being sensored or sensorless, I was merely stating how sensorless and sensored motors are typically wound (at least for RC purposes). Take Lehner's previous Hi-Amp motors, they are sensorless and can be configured into wye or delta by the user. As you stated, the difference between the windings will be a factor of sqrt(3) (1.73) in kt and kv. The point I was trying to make is how the different winding configurations are used to better suit their usage (whether it be sensored or sensorless). If I am still being unclear, say so and I will try to rephrase again .
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Old 01-04-2008, 12:52 AM   #103
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I also believe %100 in sensorless technology as yes it has been proven in many applications. The problem that Tekin has run into is they wanted to appeal to the masses and make a speed control that can run anything out there and give as many choices to the racer as possible. They have done better than anyone out there in doing that so far and are improving and fixing the bugs as we speak.

Tekin did not have to make the R1 compatible with all the other sensored stuff but probably felt pressured to do so knowing that 1 or 2 companies have the market pretty much cornered with spec 13.5 racing, and there is the problem as Tekin has many ideas on how to improve a 13.5 motor but is forced to make the motors run very close in performance to the "other" 13.5 motors or continue being "OUTLAWED". I mean there are major races that only allow 1 brand of motor, that sure must be frustrating to any other manufacturer that wants to join in.

I am sure Tekin also knows that with their own line of motors and the sensorless programming that was developed for them, people will see the advantages soon enough. I have been and continue to be waiting for an all Tekin set-up to run brushless. For now It's FX-PRO.

Have faith, that's my take on it anyway.....so far.
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Old 01-04-2008, 12:54 AM   #104
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Mate you are clear now but I still don't completely agree.

Motor design is a complex area, and I will leave that to the designers.

I don't think the winding configuration will make a big difference to suitablity for sensored or sensorless design. Winding configuration is more aimed at the number of terms and the applied voltage.

From your posts I assume you are talking about monsta trucks, crawlers ect that run on 12 cells??
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Old 01-04-2008, 12:55 AM   #105
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so basicly the answer to my question which is better sensor or sensorless is they work in a simular way but for best results you would need to use the correct motor because the way they are wound for eg (lrp/sensored) (novax/sensored) (tekin/sensorless) (GM/sensorles).
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