Magnetic strength of Neu motor
 

I recently received the Tekno RC edition Neu motor 1515/2.5D/F.
I have found that the shaft can be rotated by fingers easily.
The shaft of my 1515/1Y/F motor is very difficult to rotate by fingers.
How come they has such difference?
I thought 1515/2.5D should come with strong magnet as 1515/1Y does and hence the shaft stays firmly .
Is it normal with the 1515/2.5D?

My 1515/2.5D definately cannot be rotated by hand.

Mine would rotate, but with a good amount if effort with the shaft only. With the pinion, it was easier but you could feel the magnet strength

Yep they're tight! I was initially concerned that my rig wouldn't free-roll well when off throttle, but they do roll easier when in the actual model.

Is yours a Neu or a Tekno Neu? :neutral:

FYI.
Mine is form Impakt RC. It is a Tekno edition neu motor.
It is blue-colored, sealed end bell and has shaft with flat area.
I thought they come with the same inside(rotor and winding), and only in different version.
It seems I have a bad one. Maybe I need a replacement.

I have one of the new neu1515 1y(with 4 screws on end bell) and it is also fairly easy to turn by hand. I was also surprised by this when I got it because based on what I've read I expected it to be harder to rotate by hand. Of course resistance to hand turning is subjective. What one person thinks is easy might be hard for another or maybe something has changed in the design.

May I ask how is the performance of the motor?
If this is normal, why the new Neu motor is made in this way?
Does not less resistance correspond to less magnet field/strength and less motor torque?

I have a Tekno Neu 1515/1.5d and it does turn easier.As for performance I cant tell the differance

same here with my Neu 1515/2.5d

I don't have a good reference for comparison but when I got the motor I expected it to be more "torquey" than it was. But overall I've been happy with it. It runs cooler than the feigao 7xl I used before. It would be easier for someone who had an older version and a new one to see if there actually was a difference.

I'm pretty sure I read somewhere that this was an intentional design change. I think it may help the motor's ability to coast in neutral as opposed to effectively brake in neutral. Not sure however so I'd suggest you check with Tekno.

i can turn mine by hand as well, and the other day on the track it got up to 175*,which is far hotter then most of the others running original neus, but i think that after 20 min. of running that is acceptable, so what ever the changes are from the original ones it is still worth the praises, great motors imo, but i have never ran a original version

Guys,Thank you all.
I got reply from Tekno RC. They told me this is the new design to reduce cogging.
The performance will be the same.The rotor/stator design is a little different to reduce cogging. All of the newest Neu motors are like this.
Anyone notices the improvement of cogging in these new design motors?

Now that you mention that yes its very smooth.But it does seem to run hotter temp wise.

My neu motor (not teckno) also runs hotter than i expected. I wonder if the cogging was that bad in the older design to justify the hotter running of the new design. Anyone have experience with both types?

I was told from Tekno that the hotter temperature could be the consquence of enclosed front and rear end or the gearing problem. There should not be any difference of performance in both designs.
Nevertheless, I think maybe desing is one thing; reality is another.
If this is really trend of new Neu motor, I would be very curious about how the new rotor and stator design look like?

Mine's an older-version Neu. Apparently the newest motors from Neu have a new design to minimise cogging. :)

'new design to minimize cogging' .... What the #$!@ could they have done differently to reduce cogging?! This is almost entirely up to controller design, not so much motor... but, who knows. What cogging has to be reduced anyhow? My Neu (1512) hardly ever cogs.

I have a 1515 1.5d, and was also supprised to see that it turned over easily by hand without a pinion. I am not sure how old it is, as I bought it used. I do have a medusa v2 motor, which is supposedly a neu clone. The shaft is much harder to turn than the neu.

I can still feel the magnet poles on my neu, it does not spin as easily as a hacker of feigao.

Maybe, instead of having the stator slots be parallel to the rotor poles, they twisted the stator into a sort of helix so that the rotor's poles are always engaged to more than one "slot". Thus making it fell smoother since the poles aren't "jumping" between slots.

That would be a slotless design...

I'll give you semi-slotless. Slotless motors have no laminations in the stator.

There are varying degrees of slotless as well...

Yeah, I'm 1 min too late bro.... :tongue:

My vote would be that the stator is skewed as well. Magnetic detents (cogging as you are calling it) are determined by the magnetic pole/ stator count ratio as well as the magnet strength and motor design. I doubt that Neu went slotless, so the most likely choice is that they skewed the stator laminations. It shouldn't actually effect the efficiency, but it will make the motor roll easier and put less vibration through the vehicle.

Cogging may be the wrong term to use here. The above quote is probably the issue.

I hope this is a genuine improvement, not a compromise to help people run lower quality controlers.

Maybe they just went to a different diameter rotor to give it a little more airgap.

I have the original Neu 1515/1.5d and the Tekno Neu 1515/1.5d and the original does seem to run cooler.:whistle:

Can you quantify that? 10 degrees? Over how long?

yeah.
Please offer us detailed information about the temperature difference and running parameters.
I doubt the necessary of the "new design".Cogging is rarely a problem in my original 1515/1Y.
The Novak improves their motor performance by increasing the magnetic field of the rotor and hence more difficult shaft rotation.
Maybe the Neu goes to totally different way but that completely overthrows my concept from Novak.

Yes, do tell. This is very valuable information. I can't believe they would sacrifice efficiency... if it is the case that they run hotter, i wish they would have left it alone, or at the very least, IMPROVE efficiency.

I find this odd though, theoretically, a slotless motor should be more efficient, and more power dense, but from what products are available, this is not the case. I wonder what would come if Neu made a good slotless design, targeted around efficiency (I've seen slotless designs hit 98+%), but obviously, power density would be reduced, but then again, we don't even use these motors to their full potential, so it might just end up being a winner. Most ppl only push their motor to roughly 60% peak power.

I never had problems with my original Neu 1515/1.5d cogging.