Nickel Plated, Sintered rotor!

[ElectricThunder]

Got my rotor in the mail yesterday, and today I finally got to mess around with it. My first impression was that it's probably twice as strong as the velociti rotor I was using, but is less in diameter.:eek: Anyways, with that said, installation was a pain in the butt because the dang rotor wanted to just cling to the stator no matter what. LOL! Once I stuffed it in there properly, and wrestled with it to get the endbell on, it was good. I shimmed it so that there's basically no play in the shaft (ever so slight); so 3 very thin shims on the front of the rotor.

Next, the motor went back into my TT-01 at the same gearing 21/61. This gearing was the "sweet spot" when the velociti rotor was new. For the sintered rotor, it seems its undergeared now (it spools up much faster than before, and temperatures are running low compared to the old setup at the same gearing).

Ah yes...temperatures. I just ran it today, and it must be a good 94 degrees fahrenheit out (not counting humidity). I was burning my feet on the white sidewalk, let alone the black asphalt (OWIE!). Anyways, my Duratrax Flashpoint said the ESC was only about 110-115F after a good 15 minute run on a set of 6 GP3300s (assembled in a MEC SPT). The motor heatsink was 115F, and the motor can was 130F. This is all a good 20-30 degrees cooler than what the system would have run at in this kind of climate with the original rotor. So far, from a temperature standpoint, I'm impressed. I also seem to have some serious "torque steer". If I nail it from a stand still, it tends to want to hook to the right despite making the trim biased towards the left a bit. Hmmmmmmm.

The next test is to gear up to a 22 tooth pinion (I think that's the largest I can fit with the stock spur; so I may have to hunt down the "speed" spur). [Turns out I can't find my 22 tooth pinion, so I'll just run an IB4200WC 6 cell pack instead; this pack has a lot better voltage under load than the GP3300s]

So far so good.

[SS Pede]

Cool beans. I don't have a temp gauge, but in my Stampede I went up a tooth on the pinion to 17/87 when I installed the new rotor. I would have kept it at 16/87 to test, but the darn set screw on the pinion got rounded out so the pinion is stuck on the old rotor! I need a good 1/16 driver.

But anyhow at 17/87 the motor pulls every bit as hard as it did at 16/87 with the old rotor. Though I can't measure it, I bet my temps are lower than before too so I'm hoping the system will be even more reliable than it has already been for me (if possible). :)

[Grizzbob]

Yeah, 20-30 degrees F cooler sounds about right, same deal in my 13.5, with the bonded rotor, I get temps after a 5-minute race of around 140-150 or so(because I'm pushing it as hard as I think I can get away with, gear any taller & I definitely run the risk of a thermal shutdown in the middle of a race, bad juju, :p), but with the sintered, I can basically gear it any way I choose & I've never had it come off any hotter than 120 degrees(& I really mean it about gearing up, like going from a 6.3 FDR with bonded to about 4.6 FDR with the sintered). Gotta love it.....:cool:

[ElectricThunder]

Holy crap Grizzbob. That's some seriously tall gearing that little motor is pulling! I can tell that the 5800 with the sintered rotor is dragging its feet at 21/61. I wish I had that dang pinion and different spur! AHHH!

I'm thinking about taking the motor out of my TT-01 and using it with the HV ESC in my Rustler (whenever I get around to fixing the idler). The TT-01 is too limited in gearing at the moment, so I think that it will be receiving the MM5700 for fun. Maybe I'll run some 12 cell runs with the motor to see how it fairs.:D

SSpede- How does the motor with the rotor handle larger tires like on your pede? Think it'll handle Proline Mashers alright?

[scoob]

My 5800 used to be geared at 18/87 in My T4 for racing with the standard rotor. With the sintered it is now running 20/87 and cooler than it was. It has the same acceleration and a little more top-end with this setup.

With the new rotor my Novak motors are the most efficient motors I've ever ran. It's not even close.

[ElectricThunder]

Nice scoob. I noticed after a full run in the TT-01, the motor was 130F with an outside temperature of around 95F. The black asphalt was WAY hotter. I'm impressed.

The motor is going in my Rustler now, since I've had overheating problems with that truck in regards to motors. To keep the ESC side of things cool, I'll be running my HV maxx. And..if I feel the need to get crazy, I'll throw 12 cells at it....;)

[CharlieS]

There should have been a small instruction sheet in with the rotor that explains how to use the "tube" it comes with to assist with the instalation.

Makes it MUCH easier.

You take the old rotor out, Slide the Tube into the motor empty.

Then, slide the Sintered Rotor down the tube and into the motor. Be Sure to hold the Shaft firmly with pliers, it will want to snap into the motor and can damage the sensor board.

After the rotor is seated into the rear bearing, slide the tube out, and reassemble the motor.

Voila, No Stuck Rotor. :)

[ElectricThunder]

Yeah...about those directions. I didn't use them.:D

How come the sintered rotor is smaller in diameter than the bonded rotors? I can only imagine how much more torque it'd have if it were the same diameter as the bonded rotors...:D Or does the airgap have something to do with it.

[Grizzbob]

Yeah...about those directions. I didn't use them.:D

How come the sintered rotor is smaller in diameter than the bonded rotors? I can only imagine how much more torque it'd have if it were the same diameter as the bonded rotors...:D Or does the airgap have something to do with it.

I believe that's it, actually. If the sintered rotor were the same diameter as the bonded ones, motors like the 13.5 would make WAY too much power, considering its purpose(to be close to the power of a brushed stocker), As is, the sintered rotor already makes it stronger than any brushed stock I've seen(more like a 23 turn, imo), & I think the efficiency might be a factor too.....:cool:

[ElectricThunder]

I believe that's it, actually. If the sintered rotor were the same diameter as the bonded ones, motors like the 13.5 would make WAY too much power, considering its purpose(to be close to the power of a brushed stocker), As is, the sintered rotor already makes it stronger than any brushed stock I've seen(more like a 23 turn, imo), & I think the efficiency might be a factor too.....:cool:

I figured the Kv would take a dive since Kt would probably rise dramatically with a "good" rotor of that size. I never thought about efficiency taking a dive though. Interesting.

[Grizzbob]

Well, think of it this way(little history lesson), when Reedy came out with the MVP stock motor, they let it be known that it had the strongest magnets they'd ever put in a stocker. And of course, at first we all thought that'd mean it'd be the motor to beat, & it certainly did make strong torque, but those magnets were actually a bit TOO strong, actually slowing the motor down(stocks tend to make their best power when they're free to rev, & the MVP just couldn't do it), & at the same time, it just WRECKED the motor's efficiency. When I was trying to make it work, I tried it in a 1/12 scale, & I even had trouble making time in a race with them(& that's with 3000mah packs, at the time), but with the same setup, batteries & gearing, when I switched to a Trinity P2K2(which would look similar on the dyno to the MVP), I suddenly had NO trouble making time, & it was that motor's effieicny that made the difference. TheP2K 2 could make good torque too, but its magnets didn't overwhelm the magnetic field of the armature, so it would run better in the car(now I don't have conclusive proof of this stuff, it's just my own observations & experience). And my suspicion is that it's a similar deal with the 13.5 & sintered rotors. As it is now, it's just the right balance of rpm & torque, but put much more magnet in there & it might spoil that balance(might improve something, but you might lose more of something else in the balance).....:cool:

[ElectricThunder]

I was getting at lower turn motors other than the 13.5 (like my 8.5, or even the 3.5). But the same still applies I would imagine. Thanks!

[ElectricThunder]

OK! Finally got the HV ESC and SS5800 with sintered rotor transplanted into my freshly rebuilt Rustler (all steel gears with a fair coating of moly grease on each gear; very little resistance).

I'm running 16/90 gearing, 6 cell IB4200WC side by side packs (I need to investigate further with my batts; I think one pack is fried), and Proline Masher tires.

After messing around outside in roughly 90-95 degree heat (humidity is beastly too; I was sweating as soon as I walked out the door!) for a roughly 10 minute run, the motor was at 126F and the ESC was at 110F. Batteries I didn't temp, but they were cooler than the ESC (probably around 100F). Now, this is pulling wheelies all over the place (with the slipper set about 1/3 loose from locked) and trudging through both thick and thin St. Augustine grass.

Needless to say, while top speed wasn't impressive (maybe around 23mph), I was impressed with the torque on tap and the running temperatures. I'm thinking I'm undergeared! I will try 20/90 later with a fresh pack (my other IB4200WC pack).

I'm also going to try it out with my GP3300 pack assembled in an SPT.

Edit: Just tested with my other IB pack (fresh off the charger); the truck has a whole new life to it. It's fast and has plenty of power now (ESC still around 110F, and the motor was almost 130F, still not bad at all). I think my other IB pack is just giving up finally. ACK! Maybe I should buy a lipo when the other pack kicks and I come home for the holiday season.

[SpEEdyBL]

Are you going to run this with 12 cells?

[ElectricThunder]

Yup! Got both packs charged. I think I'm going to leave the gearing and switch to Road Rages though for 12 cells. I can't find anything smaller than a 15 tooth in my toolbox, so I don't want to run 12 cells with the Mashers. I need to rewire the ESC. I have it set up for just one 6-14 cell pack through the lead that has the BEC (don't really feel like disabling the BEC). So I need to re-wire the second terminal for the second pack; then when it's not in use, I'll just make a jumper from one of the female deans plugs I have laying around.

[TheSteve]

I won't be impressed until its faster then my Micro-T... :)

It sounds like the sintered rotors really transform the Novak - shame on them for not using them since the original SuperSport release.

[Grizzbob]

I won't be impressed until its faster then my Micro-T... :)

It sounds like the sintered rotors really transform the Novak - shame on them for not using them since the original SuperSport release.

Well, you can't expect perfection THAT early, it just took longer to dvelop the sintered rotors than it did the original ones(especially setting it up so you just need one sintered rotor that fits ALL of their brushless motors now, exact same one is used in all of them). Sometimes progress takes time(& I think my own patience may finally be rwarded a bit, enough of my buds at the track are willing to use sintered rotors now so I'm free to put mine back in this weekend, have had to run mine with bonded locally because the others were afraid I'd have a big advantage on them with sintered, & admittedly, the bonded rotor does make the 13.5 run EXTREMELY close in the car to a good brushed stock).....:D

[TheSteve]

It does take time to perfect a product, but they did take 3 years to release the SuperSport and brushless car systems have been around since the late 90's.

[ElectricThunder]

I won't be impressed until its faster then my Micro-T... :)

It sounds like the sintered rotors really transform the Novak - shame on them for not using them since the original SuperSport release.

On my IB pack that hasn't crapped out, it's probably almost as fast (maybe a few mph slower). It's ok, if I catch you, there'll be nothing left of your Micro-T;).:D

I'll get around to a 12 cell run probably next week (I hope); this is my last week of work, and I move away to college two weeks from this coming Wednesday, so I've been getting busier and busier!:eek:

[SpEEdyBL]

To save you some time, you don't actually need to run an external BEC for using a single 12 cell pack. It says you have to in the manual, but it ran just fine without an external bec. The esc didn't heat up any more with or without.

[SS Pede]

SSpede- How does the motor with the rotor handle larger tires like on your pede? Think it'll handle Proline Mashers alright?
Mine does fine with Moabs geared 17/87, so mashers should be OK. I haven't messed with the gearing a whole lot but my SS5800 has always done well in my Stampede, even with the stock rotor. This is on 6 cell GP3300's.

[ElectricThunder]

Mine does fine with Moabs geared 17/87, so mashers should be OK. I haven't messed with the gearing a whole lot but my SS5800 has always done well in my Stampede, even with the stock rotor. This is on 6 cell GP3300's.

I'm at 16/90; I'm going to try 16/87 with the mashers.:)

[SS Pede]

Wait, do you have a Stampede too, or are we still talking about the Rustler? In any case, 16/87 should no problem at all. I ran that gearing for a while without the sintered rotor.

[ElectricThunder]

I have a Rustler, but I put Proline Mashers on it.

[ElectricThunder]

To save you some time, you don't actually need to run an external BEC for using a single 12 cell pack. It says you have to in the manual, but it ran just fine without an external bec. The esc didn't heat up any more with or without.

You mean just running the 12 cells in series on the lead that is connected to the BEC? I emailed Novak a while ago and they said that the BEC is rated to around 10 or 11 volts I think. If I were using a crappy traxxas receiver, I'd do it, but I don't feel like blowing my spektrum. Maybe I'll test it out on a spare AM receiver I got laying around and see how it works first though.

[SpEEdyBL]

better safe than sorry i guess.