Owning and operating a factory in china probably saves you 30% of the cost. Because they can do everything in house with lower overhead then say you or I. It’s crazy the amount of volume they can put out also due to the low cost and large sums of money they have flowing through them.
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Yep. I am converting my existing hubs and it requires a lot of parts. Easier starts from scratch.
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I cant agree more, but what about DIY 
You seem very experienced in this topic, and when i saw your profile, wow All i want to say it is great to have people like you in these forums.
Anyways, the way i look at this is to stop the heat from the start, not have it be made, then try to dissipate it. I was wondering what causes it (friction and inefficiency?) and if there is ways to stop the heat to be made in the first place
Resistance of the copper is the biggest heat factor in a motor.
A common case is where a motor is too small, the motor say needs 20a to give you what you need. Now you heat up the motor, and the magnets as they get hot, lose magnetism. So as they get super hot, they get weaker. This leads to you needing 25a to get the same acceleration as before. But more amps, means more heat. And that heat is proportional to the resistance of your motors winding. Then, the stator get saturated from the heat and power, and it struggles the iron struggles in the stator struggles to continue fliping the poles. This leads to more inefficiencies, which mean more amps, say now 30a to do the same. But what drives these problems? Heat!
The real solution, is a bigger stator, more copper, and stronger magnets, good bearings, and proper epoxies. There’s many other tricks that hummie is researching right now and working on trying. I think another motor type might be the solution, but I need to research more.
There’s also the idea of using the truck as a heat sink. I know Jason would like to think he came up with that idea. John and I talked about that years ago with the hummie v1’s. And the agreement was that the truck, by accident, not design, acted as a heat sink very well.
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Care to share?
no hurt feelings if not, its understandable lmao
think tesla
Tesla has a very interesting design regarding reluctance motors. If that is what you mean? Would be interesting to see it pulled off on an eskate.
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That’s exactly what I mean. There’s a lot to learn from their designs. But idk, it might not be practical in a smaller form factor, who knows. I just think everyone is stuck on the same design of permant magnet motors, with one of two stator teeeth count. I think we’ll see new types in the future that could give us better efficiency and torque, like the reluctance motor.
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If u could drive a reverse reluctance motor and able to spin it really fast, with a gear which this thread is definable not about, it could work well I think. Or maybe a really large one would go direct drive but magnets help w low speed torque and maybe you’d need a giant gear with even a giant one of these motors to get similar high torque efficiency. . Larger…not larger form factor.
Tesla’s has mags in the stator so maybe some iron loss drag in that but a true reverse reluctance w no mags would have a completely free coast which is highly desired for us.
For a high torque motor in a …small…size. The bldc with the great magnets is pretty awesome. I hate that expression form factor. Wonder if the Vesc could drive it.
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Same here man! I hate that term as much as one stop shop.
Do reluctance motors run cooler? I heard yes but can’t find anything definitive
Not as a direct drive unless huge but if u geared it a lot and add some Tesla engineering for sure. If u could run it on Vesc I’d like to know. All figures of speach irk me. Or all hackneyed marketing expressions which are void of meaning. “Full carbon”
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R Spec? 
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Could one just double up on the number of motors? although the gears would be the first thing to fail in this kind of design imo. I dont exactly know how long gears last in these applications.
Take a look at @JayKay e trucks, they use a magnet less design, don’t remember if is reluctance, I think not since it’s really hard to get it right and also the control is different, if you connect a reluctance motor to the VESC it would not work or at least not properly
The life of gears depends on the type of gear and how it is protected. They can last a long time or very short periods of time. Friction and debris are your enemy. So lube and sealing it off are the first steps to a longer gear life, as well as the gears angles.
The jaykay thing must be tiny power with its tiny airgap diameter and also no magnets.
Magnets are good. Embrace the magnet. @torqueboards has with maybe the thickest steel behind thrm and bet helps. The downside to magnets is the eddy current and hysteresis they produce creating inefficiency and even drag when powered or even unpowered while they spin around. If the magnets were much smaller and all arranged in a hallbach can keep the mag field completely out of the steel rotor n make better motor that way as less losses and heat produced in rotor and magnets and easier coasting. I haven’t seen ever a top potential magnet bldc outrunner. Rectangular wire with a stator designed for specific wire and turn count for full copper fill with maybe a cobalt stator and even .15mm laminations at least and the hallbach. There’s still room to improve theses motors while staying within their volume. You could even get lighter w the hallbach n removing all steel behind the magnets, if you wanted to make the effort. But I think the easiest things to improve their already made motor would be to press another layer of steel cylinder behind the magnets, or gluing some thin shim magnets between the rotor magnets making somewhat of a hallbach. If u could acetone or bake and remove the magnets and build it from a start even better. And get stronger magnets with high heat ability.
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I’m late to the party. You kinda got it backwards (no offense) : the sides are got because that’s where heat is diffused, which means it is literally trapped inside the can and doesn’t filtrate through it. Hence the thermal picture
I can feel the salt in this thread lol.
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what i meant is that we should cool through the sides. As pointed out somewhere in this thread, making holes in the can might make the heat diffuse, but you have water/debris coming in, which make is not worth it.
To fix that you would need a design like @LEVer 's where they cool through the sides. see for yourself
none taken, i was wrong in the details, but my point still stands I would love to see the OP of that thread (sadly he is inactive nowadays) do some more thermal images, and maybe open up the motors to see inside and double check the heat sources, and bring it from a theory, to reality.
Lastly, @stormboard1 should retitle as DD comparison, because there are so many at this point… its gonna be an interesting one 
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I’d like to see it too! Another way is using a full closed motor, ferrofluid inside and patch fans around the can. Ferrofluid will create a thermal patch to draw heat out from stator toward rotor ; fans will cool down the can and protect the magnets. Double win.
Meanwhile you guys got me back to playin’ with motors and bearings instead of sleepin’ 
Literally had to replicate exactly my tiny motors, started a long resizing process haha 
I’ll sleep tomorrow 
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