That’s what the magnets would do: less cogging torque so easier coasting but at the expense of getting a bit hotter for same output power
Last flipsky motors i took apart the stator inside was smaller than you’d think. But almost the whole motor performance can be summed up and compared with ANY other motor looking at the kv and electrical resistance. Other than that the stator laminations can be a variable in performance but pretty small in our slow turning use.
Other than that it’s a comparison of the mechanical aspects and if bearings are tightly fitted. Or motor balanced. Or won’t fall apart.
looks like this new can has a single retention screw to hold the motor can to the motor shaft. This looks like a failure area to me for sure. They use the same bevel inside the can as many other companies to increase the area of contact with the shaft, but a single retention screw will probably be a weak link for this can. At least that’s what my TB motor experience has shown – and there’s whole threads dedicated to this
I have been waiting on a 2020 v2 antispark for just over 30 days. There is a USPS shipping label, but they are still waiting for it to arrive in-country.
Got it, I always thought it looked backwards but didn’t know why.
Don’t you lose some strength though? I get the fact that it’s more uniform which translates to less cogging (right?) but there’s more distance between the stator and magnets now right?
Oh wow. I always thought that the curvedagnets are preferred because when installed with the concave side facing in they reduce the airgap and increase the efficiency.
Yeah this has always been my assumption too. I would have guess less detent/cogging could be dealt with small angled magnets or more magnets so you don’t sacrifice the airgap and efficiency
the magnets that way will likely make the motor less efficient as the magnet is further away from the stator. Maybe if it was a 200kv motor with normal magnets and then they switched to those convex magnets maybe it would go to 250kv…and then you’d have to do another turn of wire on the stator side to get back down to 200kv, and that requires thinner wire and more electrical resistance and bit more heat.
but will produce less cogging and cogging torque, so coast easier.
then again it could produce less “noise” having a more sine shaped magnetic field produced that would pair better with the stator and have less losses in that way.
So in summary and in general, curved magnets are good and depending on the curving direction, you’re trading cogging and efficiency for smoothness and noise?
If concave u can get stator closer to the magnet n gain efficiency w lower copper losses as can use thicker wire for same low kv. Concave assists the main goal of the motor in producing max power w least heat.
If convex it can lower cogging torque which is a small loss but nice for us who like to coast. convex will produce a more sine shaped magnetic field as the magnet passes the tooth and can be more efficient if not trying to get high power. Surprise to see.
Smoothness being less indent or cogging torque
Noise meaning magnetic field noise w stray field n producing iron losses. I’m guessing the convex magnet would have less noise and therefore less current draw at top speed w no load.
Here is a paper on the subject of tapering magnets this way. Its a very minor optimization. Looking at these flipsky motors I think they went a bit to aggressive with the ovaling but who knows.
