So for my next build I’m looking at building a 16s6p p42 pack, so I’m looking at motors and was paying attention to recommend voltages I hadn’t done this before as all builds and cuurrent pre built I own are 12s and always went the standard way of flipsky BH motors. So as I start looking at the specs of the motors I realise that up to the 84’s 13s is the highest they recommend and on 100s it’s 12s.
Have any of you turning 14s and above still used Flipsky or are you using different motors rated for the higher voltages.
Any feedback suggestions greatly appreciated
Cheers.
Motors don’t care about the voltage unless it enough to jump the insulation, which is well in the thousands. Just be aware that speeds will increase with higher V, so you need a bigger reduction to the wheels if thats not what you’re going for.
Yeah, I think bearings play a huge roll in this, whenever I talk to reacher about HV and motors and KV and what not…they only have 1 concern…RPM. They are recommending no more then 12000 RPM for their motors
You can actually pump a lot higher voltage than rated in BLDC motors without problems, so long as.
The heat is kept to less than the demagnetization temp of the magnets. Think it’s around 80C or something.
You don’t drive the motor past its mechanical limits which for 63xx is around 10-12K for most motors.
The bearings in the motors can handle upwards of 20-40K rpm without problems. I think it has more to do with the outer can acting as a large (and largely unrigid) spinning shaft. At a certain speed, it will reach its critical speed.
Inrunners rpm limit is largely limited by centrifugal forces pulling the magnets out of the rotor. That is why the magnets are typically epoxied, then wrapped in a high tensile fabric.
So ivf just woken up, thanks for all the replies. So it looks like the Flipsky motors should be fine as long as a few thing are kept an eye on.
I’ve also been told that there are a few motor brands which make motors specifically for HV Maytech, Biobosrds and Lacroix. I’m yet to check prices on theses but I’d imagin thd last 2 will be quite expensive.
I did a lot of tests which was involved spinning “high” KV motors to not so safe speeds at 20S recently
What really bites you is motors that have a big bearing supporting the can
Now, if the big can bearings is ZZ (metal shield), it gets too hot, the grease turns into a liquid and gets thrown out within minutes of running it into that speeds, the bearing gets dry and start to wear really quick
If it’s RS (rubber seal), it gets even hotter due to the seal friction (we are talking something between 50 and 100 W of heat just because of the seal at those speeds), a bit of grease also flies out, but most just stays there and cook to the point it’s not effective anymore
If you still wish to spin fast, look for shorter motors without a can bearing and that are vented for plenty of cooling
Also keep in mind core losses (magnetic losses that are proportional to rpm) also get to a point in which they are more than the motor can dissipate. On other words, spinning most motor we use fast is hardly the most efficient way of gearing a board
