Bob Novak

Since Charlie is on his way to Cleveland today I thought I would answer some questions. The main reason the sintered rotor runs cooler is that it maintains the same output power with less input power than a bonded rotor. In simple terms the heat generated in any motor comes from the power loss in the motor itself. Thus since there is less power loss with the sintered rotor you have less heat buildup. Heat generated from air friction is minimal if any in a brushless motor as the rotor is very smooth.
Bob Novak

Bob Novak

As Charlie said earlier it is hard to guess what motor tuners will do in the future. One thing for sure there is far less room if any to improve on the brushless motors compared to brushed motors. A brushed motor runs at anywhere from 45% to maybe 60% efficiency. A brushless motor will run close to 90% efficient. Secondly our brushless motors are designed using a very sophisticated computer program. Thus we can maximize the performance before we build it. I also want to thank all the people out there that have purchased our products and are having so much fun. We designed the 4300 and the 13.5 motors to be spec class motors and frankly I am amazed that nobody else has not jumped on the band wagon. The only problem there is they have to build their motors to the exact specs as these two motors for everything to stay as close in racing as it is now. If they do then we welcome them to do so as it can only help us all in the end.
Bob Novak

Bob Novak

The updated solder tabs have nothing to do with the timing of the motor. The reason we went to them was two fold. First it has less voltage drop than the PC Board and secondly it is easier to solder the wires to it.
Actually we designed the 4300 to be an equivalent stock motor but it turned out to be as fast as a 19 turn so that is why we brought out the 13.5 turn. This time we sent quite a few 13.5 turn motors to drivers around the country to get their feedback instead of our own. Now we have two motors that are what I like to call Spec class motors. And yes we a pleasantly surprised that they are catching on so fast.

Bob

Bob Novak

It is not a question of which rotor has the most RPM but which Rotor generates the most power under a loaded condition. This definitely is the sintered rotor. As it turns out the sintered rotor has less RPM under a no load condition but it has more Torque under a loaded condition with an overall higher output power. All our motors are hand wound and are very consistent. As far as ventilating the can this is not the best way to cool the motor. All the heat in a brushless motor is generated in the stator which is on the outside of the motor. We have found out that our new heat sink, which replaces the sleeve of the motor is the best way to cool the motor. As far as the coil wire measurement I think Charlie answered that and we will be posting the inductance readings on our website.
Bob Novak

Bob Novak

Not that I know of. For sintered magnets they are very large and very expensive.
Bob Novak

Marcos.J

iTrader: (239)

Ive been using sintered rotors and the new heatsink in all my brushless motors for a few months and havent had any heat issues

syndr0me

iTrader: (32)

Bob,

Thank you for taking the time to come here and answer questions for us. The technical responses we've gotten from you and Charlie, not to mention Mr. Black from Orion have been very enlightening. It's refreshing to the the companies out there pushing the envelope on new technology interfacing so closely with their customers.

We're all very encouraged by the turnout (large for us) for our local SS4300/LiPo class, not to mention the enthusiasm behind it. We're hoping to get some people from around the region at our "big" race in a few weeks, and will do our part at the club level, and as informed consumers to try and push this class, as it's very clear to all of us that this is the future. Hopefully we can continue to host large events, and get more interest as these classes start to grow.

More people locally are starting to see that the sintered rotor is superior in every way. It's surprising how different it needs to be geared compared to the bonded rotor. It's SO different, you might not even think to try that much gear. I believe that initially led us to false feelings of inferiority, which we're getting past now.

Do you have any feelings on what temperature the motor and GTB ESC need to reach before their performance is impacted? Currently, most of us aren't running the fans on the ESC, and it almost always comes off around 100 degrees. The external temperature on the motors reaches around 130 with the sintered rotor. We're able to get them much cooler with the heatsink and possibly a fan, but it's not clear at this point if that's necessary, at least with the SS4300.

Can you speculate on the future of brushless ESC's without revealing too much about future products? Things like size and additional features, perhaps?

I came across this the other night, which I assume is a hack job. I thought it was interesting, but I'd rather not let dirt in, especially since we're not struggling with heat (anymore) using sintered rotors.

http://www.rcinfos.com/2006/2006_11_...touring_28.jpg

syndr0me

iTrader: (32)

Also, I'm a bit curious why all the new motors don't use the "ribbed" can. Is there some technical reason, for example, why the 13.5 didn't get it, but the 18.5 did? Do you guys find that the ribbed can makes any significant difference? We definitely like the lighter endbell, which people are starting to use on their 4300's.

omaharich

I love my new sintered rotor!! We ran a practice last night at our weekly race for our upcoming Enduro race and ran a 12 min main...I have 4300 and used my 4200 battery...My roll out was 1.25 and the car came off at 119 degrees at the end!!!!! Love it, thank you Novak!! Lipo coming soon and I am highly considering the Maxamps 6000...Any suggestions for charger and lipo? Pros and Cons Orion vs Maxamps. I need charger for lipo and nimh...Going to sale my current charger and equiptment for nimh except for the pro 4200 that I have.....

UN4RACING

iTrader: (22)

Well Mr. Novak your honest and right to my knowlegde. The wire is consistant I tore down a 5800 motor and each wire was right on. I was very impressed and glad to see that. I'm more comfortable buying any motor in the case without seeing any #s. only one follow up. If I take Fresh stock rotor vs a fresh sentered witch is faster? I know witch is better but if I ran 5 brand new fresh out of the package stock rotors in a major race. Vs 1 sentered rotor. would i have an advantage? I'm talking 1 per round. would that 1 run be faster than the sentered? I think the 1 run with the lighter rotor with full magnet capasity would be faster. At the cost of 2 stock motors would that be an advantage?

........... And I compliment, you noone else exept Mr. Black Seem to be taking this class seriuos enough to get on here and help advance this class thank you. Keep up the good work. And dont forget to hang out here from time to time.

UN4RACING

iTrader: (22)

Looks like an lrp with the wire cut. Theres no reason for that. And the vents look pro. The screen appears to be inside the can? not good they may have tampered with the wire must be an open mod class.

Blue heat sink with a novak on switch. I'm not sure whats up but someone is very talented.

asw7576

You guys in here ( lipo + brushless + foams ) are living in peace, unlike in the other forums arguing 4 cells vs 6 cells.

UN4RACING

iTrader: (22)

6 cell is faster. End of argument.

Hey thats how I bird hunt.

UN4RACING

iTrader: (22)

Maybe this can help cut back on warranty calls?
It seems if the magnet is worn out, it will shut off the motor like it's thermoling?
The temp is cold but if you turn the speedo off and turn it back on it will run for a bit then shut off again.
I put in a fresh magnet and problem solved.
I heard these things operate on a pulse or something?
Does the weak magnet cause this?
Just trying to keep the thread awake, It appears everyone is still asleep on the couch from eating to much.

LATER. X Thanks again.

fast-ho-cars

iTrader: (4)

Bob

since your helping out Charlie and answered the part about the new solder tabs....any insight on the second part of Adam's previous posted question?

Charlie,

We've noticed that some of the 4300's are now shipping with the updated solder tabs. Is it true that the motors needs to be timed different in order to use the new tabs? If so, is there any chance these would perform differently? We've had a couple of guys say they're slower, and I'm just wondering if they need to gear them appropriately for that motor's power band, which may be different than those with the old solder tabs.

Did you guys ever imagine a whole class would be built around your 4300 motor? Seems like it happened because that was the slowest motor available for 4 years, and now, even though the 13.5 is available, the 4300 class has got enough momentum to keep going. Perhaps this will be the brushless 19T of the future. With that in mind, do you think there's a chance of releasing an updated version of the 4300? As it stands right now, it costs over $100 to get one outfitted with a new endbell and sintered rotor, making it the most expensive motor you guys make. It seems like an updated version would go a long way toward easing the pain of transitioning into 4300 racing. If nothing else, because the sintered rotor's ease of use/maintenance/longevity compared to the SS rotor.

fast-ho-cars

iTrader: (4)

Syndrome

at fastlane, got to see the 4300/lipo/nimh/foam sedan class first hand on sunday. it was very impressive. cars appeared to be as fast as Mod sedans from a few years back.

syndr0me

iTrader: (32)

Oh, cool! Are you local to Kansas City, or just out to visit or something? We have a good turnout on Tuesday as well.

I'd say the cars are just a hair slower than 19T. We're running LiPo or 6 cell NiMH, and not having any issues with too much speed, or burning up electronics. I'm not sure who that 4 cell stuff is for, but it's not us.

The biggest gripe I've got is that on foam tires, we're going through them very quickly. The torque of the motors really does a number on tires, especially the fronts. I'm not a giant fan of rubber tire racing, but I'm beginning to think for the ultimate low-maintenance class, that might be a better choice. As it stands now, I basically have to adjust my gearing and ride height every race. Like someone else said, we're going through tires faster than nitro.

fast-ho-cars

iTrader: (4)

came up with 7 racers from SPFD, we ended up adding 5 - 12ths, 2 oval pan, and 3 stock rubber TC entries this past sunday. our track was shutdown for T-day. it was my 5th time i've been up there. too hard to make Tuesday races there. i ran 12th, Bob put the "writ of habeus Smokin!" on the field, he had it down pat, i had a good race going with 2nd qualifier, but he got punished bad when marshalls failed to see his brightly colored car needing help on the track. i usually run stock/foam on carpet and asphalt, my Pro4 was broke O/H for parts.

i like the class you guys came up with and staying on it...but, going from track to track everybody is running variated sedan classes, someplaces from week to week, or changes occuring on the race day. so it makes it hard to travel and race sedan. BL/Brushed, rubber/foam, lipo/nimh, maybe soon 4/6-cell?

going rubber, really doesn't save money. those who change their tires regularly (like 3-4 runs, not races) will be have the advantage. costs end up being greater. many were doing 1 run rubber tires in vegas. 3 years ago i was at a track out west and we started running nitro foams on carpet. 45F 40R shores from Orion. they lasted 3 times longer than a set of plaids/purples. they were much better than running rubber which we tried in 2002.

syndr0me

iTrader: (32)

Ah, cool, glad you guys made it. I'm sorry I wasn't there to see the show!

I don't think we should switch to rubber, I just slightly envy their option of not messing with ride height and gearing all the time.

We're going to have to figure out something on the tires I think. Guys are talking about cutting down nitro foams like you mentioned and stuff like that. It's a fairly competitive class, though, so we don't want to make changes that will put us at a disadvantage unless everybody agrees to it.

asw7576

Is it really necessary to balance lipo batts ? just like everyone do with NiMH ?

I find it interesting to know that lipo balancing is actually done after charging process is completed ( unlike NiMH which require balancing / equalizing per cell after discharge cycle ).

syndr0me

iTrader: (32)

Seems to vary greatly from one battery manufacturer to another. The guys at Orion have been using their original test pack for 2 years without the need to balance it. All you're doing is charging each cell individually (rather than together) to ensure they're both fully charged. The only reason it's tricky is because of the tricks used to isolate each cell on its own by using the balancing plug. I'm sure Mr. Black could explain it better than I did, though.

UN4RACING

iTrader: (22)

I heard that if they get to out of balance one will over charge and possibly blow.
I think thats why it's best not to discharge more than 80%
WE been charging running 5 or 6 minutes letting them cool, repeaking them and running them again. In other words run a round and recharge. No black magic. No discharge or repeaking before the heat.
It dosent get any cheaper or easier than that.
Incase your wondering I'm running 4800's orion in an FK05.
That is by far the best fit for 4800's.
That is until I get that new LOSI.

padailey

iTrader: (11)

The gents running or have run lipos here have found minimal if any need for balancing. Several of us that are not running Orion lipos are gonna go together and get a balancer to share. Probably will only take about 30 secs to balance but can't hurt. If I had to buy one by myself I personally wouldn't bother. There are some Orions around also but no one has felt the need to balance them either.

I ran my lipo for 40 mins straight last weekend... only one 30 sec stop to temp everything. When I noticed the power drop I took it off the track and hooked it up to my ICE. 6.5V and less than 90 degrees.... so I'm wondering ... why are you letting them cool? Are they getting hot? I would think if they are getting hot you are running just as much risk of a problem as over charging/discharging.

Usually what I do at the track is charge it up at the beginning... then charge it again if I remember to... that's it. Of course I have a little higher capacity battery which I can make it easily an entire night. Last Wednesday I made sure to put it on the charger before the main because we ran a 12 min main. But as was mentioned it doesn't get much easier!

asw7576

Un4Racing or Syndrome : Do you equalize each cell after discharge ?

Correct me if I made wrong assumption, ...... thx to you first.

I see no point of buying balancing equipment ( hyperion LBA10) if I have to equalize both cells by bringing down one cell with higher voltage to match the voltage of another cell ( lower voltage ). I see no point of doing that.

padailey

iTrader: (11)

If I understand the balancing thing there are basically 2 ways (ok sorta 3).

1) With Orion packs if you charge each cell separately to capacity you have balanced the pack. No need for a balancer.

Packs with balancing tap
2) balance charge - not sure exactly how this works but it either charges the lower cell up to the higher or does some combination of charge/discharge to get the cells equal and then completes the charge... balanced pack.

3) balance discharge - slowly discharges the higher cell to equal the lower. Again you get balanced pack.


I had considered the charge balancer like the LBA10 but will go together with buds and get a cheaper one. I at first wanted one to hook up with my ICE to balance why I charged. But as I've researched more just a cheaper discharge only balancer will do fine. Should take very little time to balance the packs. If you have an Orion don't bother.. the ability to balance is already built in.

asw7576

Thanks buddy..... great info.

I just buy all of them ( lipo packs, charger, and balancer )

one day will be needed someday.

syndr0me

iTrader: (32)

I ran the GQ carpet tires tonight and had a MUCH better experience in terms of tire wear. In spite of the goofy orange rims, I've consistently felt these are the best quality tires I've used. They don't come unglued, they wear nice, and they don't chunk easily. They even ran well once I changed my setup to suit them. I don't know if they're a disadvantage at the top levels, but I put in my fastest runs with them tonight, and didn't have any of the recent headaches I've had with the Parmas and Jacos that wear down so quick, especially up front.

UN4RACING

iTrader: (22)

Letting them cool is only a habit. When I started lipo Mark a exsperinced lipo racer said thats how he does it, and has never had any problems. And I was used to doing that with HYdryds. There is a couple of racers that ran one pack all summer in the heat out doors, they didnt cool them or any thing, Just run'm and charge'm. No problems. I'm just trying to be respectful to my packs just incase.
My packs even with a 5.5 brushless have never been hotter than 100 or so degrees.

padailey

iTrader: (11)

I understand... I think with lipos most of us probably do things on the side of caution even though it shouldn't be necessary. I have heard they will actually cool down a little when you charge them. I haven't tried that but I'll be running tonight so I'll pay a little closer attention to the temps and see what happens.

asw7576

Anyone buy lipo from maxamps.com ? are they good batteries ?

I'm thinking to buy 8000Mah and glue it to my MSX..... is 8000Mah overkill ?

My GTB 3.5R is here now.