Need motor gearing advise
 

Hey guys,

Some of you may have run across my 8ight T thread. Anyway, I just got my Neu 1512 1.5Y in and was very disappointed with the performance. It was a downright dog. Not fast at all. The motor seems to be running right, it's just slow. When I pick the truck up off of the ground and gun it, it hardly torqued at all in my hand geared 14/46, which is the gearing that should have been a nice setup for a 1.5Y.

Well, I just ran it geared 16/44 and it's really starting to wake up. My front yard is about 50' long and I spent a solid five minutes doing sprints. Running full throttle and then slowing down just enough to hang a u turn and then back on full throttle. At the end of the run, the MM esc was at 125*F, the battery pack was at 110*F, and the motor was at 150*F. When I did this with my 9XL, the motor easily got up to 200* in that short time with that sort of hard running.

I'm thinking at this point, that there is nothing wrong with the motor. I just got one that was mislabeled. I suspect that I got a 1512 2Y, rather than a 1.5Y. The 2Y is a 1400kv motor, rather than a 1900kv as the 1.5Y is supposed to be.

Just the temps that I am getting are telling me that I can gear up even farther. Am I right in thinking that I can simply continue to gear up while watching the esc temps? If I gear up a bit more, I should be able to bring the motor temps down some too.

Those temps sound pretty good! Yeah, try gearing it up. Are you up to the speed you want yet? Still have good acceleration?

aagel, have you tried your 5s on it yet? If you did get a 2y then the 5s pack should be just about perfect for you. I actually went from a 9xl to a 12xl (1390kv) in the 8t and really liked it. However my mamba finally went so I sent it in and will be trying a nue when my quark gets here.

as for the gearing if the temps are not bad maybe try an 18t. With the 12xl I started at 16/44 and ended up 18/46 on 5s.

It is only my suspicion that I got a 2Y. I can't confirm it, except to say that the motor is running fine, just slow, when geared for a 1900kv motor. I just dropped the 5S pack into the 8ight with the same 16/44 gearing and things really came to life. It's not as stupid as the 9XL was on 5S, but it's more of a sane insanity.

I have to get my truck back out onto the track and see how it performs with the higher gearing. At this point, I am now on the fence as to whether I'm going to return the motor to Neu for a check up. If it turns out to be fast enough for racing on the track with the gearing and 4S, I may just keep it. Those temps that I got were looking pretty good to me. I'm just wondering what my runtimes are going to be like. It would be something if I could run a 30 minute main on a single Kokam 4800 pack.

AANgel, do you have an eagletree with the RPM sensor? Those things are extremely handy in situations like this. Cheap too, I think I payed <$100 for micropower, rpm sensor, and temp prob, but to this day I haven't been able the get the temp prob to work?

So you are running this Neu on 5s on your MM?

I've been running this motor, whatever it is, on 5S geared 16/44 and it's really waking up. If it is a 2Y, I'm still only turning around 24,500 rpms at max throttle.

I ran it hard for 5 minutes. Really hard on the 5S and got an esc temp of 135F and motor temp of 160F. Can I still gear higher?

I have to say, this little low kv motor turns into a beast when you feed it the voltage and it's SMOOTH. It very responsive and I'm able to ride balanced wheelies just by manipulating the throttle. It's that responsive. I just ordered an 18T pinion to try that out on 4S. The larger I go on the pinion the snappier it gets. I suppose this is because it's getting to the max rpms so quickly.

I also read something interesting on Neu's website. In the FAQ section, they say that when comparing D and Y winds, the D will turn 1.7 times more rpms per volt, but the Y wind will put out 1.7 times more torque. They also said that the Y wind will also respond better to increases in timing and recommend either a low or medium setting. For the D wind motors, they recommend a low setting.

I'm really having mixed feeling about this motor now. Should I keep it as is, or send it to Neu for inspection and possible exchange? I just hate to have to send another piece of equipment off.

And...yes, I'm running it on the MM esc. The cogging is a problem at times. Not always. In fact, I sometimes forget that there is a problem, until it rears its ugly head.

I do need to get something with some sort of rpm meter. Then I could verify myself what I suspect.

Man, this Neu is one wicked little motor. One of the things that I like about it is that the shaft on it is so long. 3/4" long from the front endbell. It makes for very easy fitting of any sort of pinion gear.

Yes, they are very useful. You can see the max rpm relative to vehicle speed, and see amps to rpm's, and so on. I think that ratio from D to Y is actually 1.73 or something, I can't quite remember... :030: :005:

Every time I hear ppl's experience with Neu motors, it makes me want to get one even more. :027:

Eagletree has an rpm sensor. Or you might do it the hard way by applying very low voltage (6v) to the ESC, paint a mark on the tire, and count the revs in one minute. Then, just work backwards from your gearing. :)

Yeah, I can see myself trying to count the number of times that the line goes by. I just got back from the "back to the beach" fund raiser and I've had quite a few Bud Lights.

aangel you might also want to pick up a 17 tooth. You can get hardened ones threw http://www.megamotorusa.com/ go to shop, rc cars, mod1 gears. I just picked up 17-19 and they look good but haven't tried them yet. They are also made by robinson racing

LOL. It was a tongue-in-cheek suggestion anyway. :)

Since you've had a few, just take whatever you count and divide by two. :005:

Can you use the neu on 5s for racing and just gear it for the speed you want? You should be able to get speed like the 9xl on 4s, but with cooler running shouldn't you.
My 1515 2.5d seems to be able to take a fairly low gear ratio (12.5:1) without problems or hurting acceleration.
I liked my feigao 7xl, but I like the neu much more.
If I was you I wouldn't sell it yet, even if you decide to keep using the 9xl for racing, because the neu sounds like it could be very good on 6s (especially if it is the lower kv version), which could be good once some better esc's come out.

Actually, I think he SHOULD sell it... to me for a cheap price! ;)

I think you'll be happy with it once you get 5s or even 6s on there. Runtime will be better and the batteries and ESC will run cooler with the reduced current. Once you get the motor RPM you need, you won't have to gear so high either.

Brian, you're killing me. LMAO.

OK, I would seriously consider keeping the motor as is, except that there is always the possibility that it isn't mislabeled, but defective.

I do have to admit, that messing with this motor has opened sort of a new understanding for me. Running it with all of the gearing, it is lightning quick and VERY responsive. I'd say that it's fast enough for the track as it is on 4S. I'll just be hitting full throttle more often than I did with the faster setup.

It did bother me that it hit over 160 in a relatively short amount of time, but I was running it really hard. Full throttle sprints for a solid 5 minutes can be considered a sort of torture test. All I am wondering is whether I'm still undergeared a bit. If it is a 1400kv motor, it's only approaching 25,000 rpms on 5S.

I sent an email off to Neu. I'll see what kind of response I get. Although I'm not crazy about sending off yet another piece of equipment, I do want to know if it was mislabeled or is defective. Now, if it is mislabeled, do I keep it or exchange it for what I ordered? I think that I'd exchange it. I have a butt load of money invested in 4S and 5S packs, not to mention that my balancer only goes up to 5S. If I went with a motor that needed 6S to really perform, I'd need to rob a bank to be able to pursue it.

Lol, it was worth a try right? ;)

Yeah, if defective, then I would definitely send it to Neu for testing. If nothing more than peace of mind...

About the temps: If you are doing a lot of standing starts, you have to remember the kinds of current you are pulling. This current at 4s or 5s is going to develop a LOT of power. It only stands to reason that you are going to heat it up. Ever feel a 75w light bulb? That's roughly about the same size, but much less power, at least a factor of 10. Granted, a light bulb isn't the most efficient thing, but you get the idea. For the sake of argument: if you are using 4s and pulling 150A, and the motor is 90% efficient, that's 216W the motor has to dissipate. Yikes.

Edit: Here's an idea: If you have a lot of 4s and 5s packs, run two 4s packs in series for 8s. :) Of course, you need an ESC capable of that, but it's only a matter of time. The rpms would be a bit high at 41k (assuming you do have the 1400kv motor), but ok if not doing lots of long top speed runs. Even then I think it would be fine - after all, these are high-end motors...

I agree, the only way to solve this problem is to go to 8s and tell us what happens:dft012:

I was just checking where you got that motor from. I don't see it anymore? :032:

Check it out.

I just got off of the phone with Neu. It appears that their labeling process consists of a person marking one of the motor leads with the wind of the motor and then the remaining labels are marked according to what's written on the motor lead. If the lead was marked wrong, then so are the rest. I guess the motors aren't tested to be sure that they perform the way they are supposed to. I was also told that the turn around time would be about two weeks. GREAT!!!

Did they give you an option to exchange the motor for one you want if the label is in fact wrong? Did you ask them if there was a simple method of determining the kv with what you have on hand?

Brian, they didn't suggest anything except to have me send it in. They did say that they would make it right. If it is the mislabeled or defective, they will replace it.