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  1. L

    Sanity check: outrunner with large no-load current, low inductance

    Well, serves me right for being naive and just assuming a not-horrible design. Yeah, alien power. Anyone happen to know what the general consensus on the 80-100 outrunner variants is? From what I've haphazardly found they seem at least passable: halved pole counts -> no more than 1/4 the iron...
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    Sanity check: outrunner with large no-load current, low inductance

    Welp, looks like its a poorly designed motor all around. Others have found the same issue (https://endless-sphere.com/forums/viewtopic.php?f=30&t=20840&start=100#p307898). Seems to be mostly core losses. Thanks for the help though, now I'm fairly sure it's not just me making a stupid mistake...
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    Sanity check: outrunner with large no-load current, low inductance

    I'll definitely try sweeping rpm (for eddy losses) and voltage (for ripple current losses) and measuring the unloaded power draw. Have I maybe oversized my motor? I was aiming for around 3kW continuous mechanical power and around 5kW peak (10-second) power at around 5-6kRPM. Would a smaller...
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    Sanity check: outrunner with large no-load current, low inductance

    Completely reasonable suggestions, but (as I forgot to mention :oops: ) the motor controller is running sensorless. I've measured the BEMF and all phases are similarly rough sinusoids. Also, for what it's worth, when running at low speeds (unloaded, around 50 rpm) the current consumption is...
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    Sanity check: outrunner with large no-load current, low inductance

    Hey all, this is just a quick sanity check to make sure that I haven't made some obvious mistake. I have a 12090 140kv outrunner (28-poles) I am planning to use for an electric outboard rebuild. What I've found so far (that I didn't expect) is: - Running unloaded at a pack voltage of 40V...
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    Yet another homebrew BMS: functionally simple, modular, displays cell voltage

    This is one drawback of the design, I haven't really made much of an effort to keep things super cheap (though by no means are any of the parts ridiculously expensive). A rough estimate (+/- 30%) is around $10 for the master device (which you need one of) and around $8 for slaves (which you...
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    Yet another homebrew BMS: functionally simple, modular, displays cell voltage

    So for a few different projects I've been working on I eventually caved in and made yet another homebrew BMS. IMO it turned out pretty well (i.e. works for me and no battery fires to date), and someone else here might also have a use for it. Unlike most BMSs I've seen so far, this one; Is...
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    Suggest motor for ~3kW cont, 4-6kRPM, 100A

    I'm currently in the process of an electric retrofit of small outboard engine. So far I've used a small hobby-type PMSM (~8kRPM, 3NM), but I've found that it's a little too underpowered and a 3:1 transmission stage I built had more losses than I could afford (~300W). Because of these reasons...
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