I wrote out exactly what the erpm is at 6s, (weighted and theoretical) and I wrote 4s would be less.
Either way, I would not have to change motors, and you have no basis for saying that.
I’d love to know why brushless motors are hitting much, much higher erpm on much slower regular esc. After all people run them on 10s and 12s, and the large helicopters don’t suddenly fall from the sky going over that limit.
Not sure why you’re taking offense to someone who’s trying to help. You wrote that you’d have 93k erpm, which is above 60k, so don’t say I don’t have basis for what I’ve said, you’ll have to take that up with Chaka and Vedder. Running 4s will cause a lot of current and heat; general consensus is that 6s is minimum to run on the VESC. And yes, people run the VESC on 10s and 12s, but on much lower kv motors for much less erpm.
Like @flatsp0t said, you can run it if you want, I’m just not confident it’ll work well or long.
Large Helis do not use VESC. Their ESCs use Voltage control and not Current control. It might work. With 4s the amps will kill you VESC, with 6s or more your ERPM will result in a blown DRV chip. Thits is what @chaka and the others told you. Till then, i bet we will se a “buhuhu my vesc is Dead” tread. Try it and learn or leave it and trust people with experience with the VESC.
Edit: Ninja @Jinra
Who would do such a thing? Chumps, that’s who.
190kv is probably the sweet spot for 12S on VESC, but i’ve been told it bumps up against the limits. Any who its what i use. CUZ I BUMP LIMITS YALL.
Bump them to space.
… or your VESCS back to chaka.
based on what i read here yes it looks like 190kv is the sweet spot for 12s, now i also read that if you go higher than this you might be compromising top end perfomance, what if you lower than 190kv like 149kv with 12s??? @chaka
I’m running 149kv with 12s and I have noticed 2 things that you’d completely expect: the motor has more torque for a given amount of current, and top speed is reduced (16T/40T–> theoretical top speed of ~28mph… more than fast enough for me). The ERPM at top speed is well below even the more conservative 60k (i.e. motor rpm max is about 6600).
I’m not running FOC (though I’d like to) since it apparently kills DRVs with some regularity… i.e. numerous reports of DRV errors for no apparent reason after running on FOC for any length of time. If VESCs were easier to get or repair, I’d experiment with FOC since the low ERPM of this setup might prevent drv errors… who knows…
Well, from my point of view, you ignored that I’m running 2 motors, so amps are /2.
If you can’t run 4s with 2 wheel drive without smoking a VESC, then every 1 wheel drive at 8s would also be toast. Do you follow? And on top of that, there’s current control, so telling somebody oh buy more stuff, is not helpful.
Again, I don’t see any basis that I need new motors. Saying you’re helpful, doesn’t mean you are helpful.
@flatsp0t thank you for for you answer, can you tell me why the erpm is being calculated with a theoretical erpm when the weighted rpm is less? You won’t hit the theoretical RPM with some help from gravity or a tailwind.
It doesn’t matter if you’re running two motors… You’re still hitting the eRPM limit of 60k regardless of whether you’re on single or dual drive.
You’re really unhelpful, obviously I put two paths as possble and 4s path is way under that erpm. Please stop addressing anything I have to say if you’re just a troll who doesn’t see facts.
Alright, you obviously don’t want my help, and that’s fine. Good luck with your build, and I hope it goes well.
To me it sounds like you are the troll here…
wtf have u ever contributed i didnt even know u existed until a minute ago. As for running higher kv motors the 300kv limit was set for a reason if u wanna experiment go fucking do it but dont start calling members who have helped others on more than one occasion trolls. Dont forget to let me know when u fry your vesc or overheat your motor tho:grinning:
Here we go again… Stop calling members names. They have been here for much longer than you and are a lot more experienced. Unless you want to blow your VESC just listen. No need for more arguments.
SSIILLEENNCCEE!
The reason for 300 KV limit is because htd5 won’t let you get the erpm low enough.
No esc actually can tell what the KV of the motor is, only erpm. @chaka wrote in this very thread about using motors above 600 KV as possible.
There is no limit to motor KV, got it?
Try it out and let us know how it goes. It’s the only way to find out for sure if theory matches reality.
You are just so full of yourself. The KV limit is there because at some points the needed reduction is just not possible anymore with the available pulleys. Ever thought of that? With a 500kv motor and 83mm wheels at 10S you would need 14/80 gearing to reach a speed of 50km/h. Now have a look how big a 80t pulleys is! Well first of all maedler does not even have one in in their store so you’d have to settle with 72 as maximum (top speed would be a ridiculous 56km/h). But what diameter is a 72t pulley? It is 115mm. Do have any idea how big that is? It is bigger than your entire wheel. So the maximum you could go with would be a 48t pulley which would get you to 84km/h - you see that what you tell us makes no sense? The 300kv are there for a reason!
Edit: You said yourself you want to use a 5:1 reduction with HTD3 belts. How exactly are you planning to do this? You could go 14/72 as the 72t pulleys is 69mm but the 14t is only 13mm - that is so small that you probably can’t even confidently put it on your 8 or 10mm motor shaft.
Also have fun coasting on this thing 
Leave him, he is not worth it.
would have been fun seeing him order these pulleys and only later realize how bad of a mistake he made 