This makes no sense. Motors have mechanical RPM limits, especially outrunners.
At 100v it will spin over 18k RPM; the bell will literally fly away from you.
I would argue you don’t need that much power in the woods. It would be geared for high torque since you’re not gonna do 70km/h offroad anyways.
For a street pnum-pnum board on the other hand, there’s never enough power. I got bored with dual 6380 @ 100 amps cause it didn’t pull hard enough.
I had a slightly bent 8mm motor shaft once, would rather have an unbent 10mm one.
Don’t see a lot of downsides to 10mm shafts except small pinions on geardrives not being possible.
hahaha this is exactly why I just bought the FS 6374 motors last week. I was defeated by a hill yesterday, that is unacceptable. I also feel like it’s not as spunky as it was with urethane, even though I sized my gearing appropriately.
Anyway, I’m looking forwards to @YUTW123 motor developments. Congrats on the new territory.
As long as the motor is well balanced such that you’re not overloading it for quick heat buildup before it can dissipate, then high rpm shouldn’t really be an issue provided the bearings can handle it. 100V might be a bit on the high side, but esk8 shouldn’t be that taxing on a motor of that size and KV (obviously dependent on how much current and gearing you’re pumping through) but it’s nothing too unreasonable I would think.
I’m stuck with a 2:1 gearing atm so would ideally like a little less KV
At those rpm you will probably melt the motor by core losses alone, it will something on the neighborhood of 300 to 400 W just to spin the motor And all that has to be dissipated
It’s a linear relationship between voltage and loss for the same amount of current, so you will be getting double the losses at 100V compared to 50V (ignoring bearing losses and drag) but that aspect alone shouldn’t be dangerous for the motor provided the current supplied isn’t too much when the motor is under load
I use my (awesome kicktail) board both on street and offroad with dual 6374 (170KV) and I def could use more power. It’s true that my gear is too high though (over 70 km/h).
Yeah mine is 15:55 to the bergs. Granted the hill was incredibly steep and dirt pack so I probably could have ridden it better but the motors were pretty much maxed out too
Alright here’s an update for people who are intersted in these motors. They are good in concept, but there are some serious things that could be improved.
1: Phase wire and sensor wire length. They are just WAY too short. I would say that the Maytech motors have it perfect, about 300mm length on phase wires and 500mm on the sensor wires. You can always tuck away extra wire, but extending the phase wires and sensor wires is a real pain. This is especially true for applications where you are swapping motors onto an existing board. With the lengths that the phase wires and sensors are at, you are pretty much guranteed to need extensions.
2: Assembly quality. Overall it was pretty nice. There are some nice touches like epoxy that goes over the hall sensors, but there is a major issue. I’m making this post on behalf of @KaramQ because I helped him out on a swap he’s doing. The major issue here comes where the phase wires are routed inside the motor. This particular swap involved a Lacroix board, Lacroix mounts, and the usage of the smaller 30mm mounting pattern on the motors. The issue comes in where the 30mm mounting pattern meets the phase wires. Namely, the phase wires are DIRECTLY underneath the holes. While this is a specific application, having them right underneath the holes is risky, and with the default Lacroix motor bolts, the phases short out through the faceplate of the motor. I was able to give Karam some new motor mounting screws to use instead, that are a bit shorter. However, I was not able to do anything about the phase wires being right underneath the holes.
3: Balance? Stator rubbing? Noises? One of the motors from the factory came with a weird noise, kind of like weird bearing noise. However, after opening it up, it appeared that the stator was actually rubbing on some of the magnents. Not really sure if this is a fluke or not, but just presenting information.
4: Phase wire hole space. This is the biggest issue that I found when assembling. The hole that the phase wires come out of is so tight that it almost feels like it’s cutting the sensor wires. On one motor, the mesh that goes around the phase wires was actually cut a bit. I would recommend making the hole a little bit bigger or improving assembly.
Below are some pictures that I took with the motors disassembled
Out of curiosity, are you running sensored or sensorless? I feel like I would be inclined to run sensorless because of a potential short what with the issue you pointed out. Maybe I’m just paranoid.
I am not the one setting it up, that would be a Karam question. Personally I’d probably run HFI if I was setting it up on that Lacroix with the Stormcore
This is such a weak point on bldc motors… if you took the wires out you could coat the edge in something to prevent cuts or install some kind of rubber grommet.
Thx for that update. Always nice to see motors from the inside.
I definitely miss epoxy between the magnets.
They look like my APS 6384s where the epoxy is just used on the backside of the magnets to hold them in place. That didn’t last long for my motors.
