EMAX MULTI COPTER MOTOR 2212-920Kv

[Yosser70]

I would think they can be used with 4s lipo, but you would need to prop down to 8 inch. im not 100% on that so you would be better off waiting for confirmation from others.

So it';s not the extra power from a bigger battery but more they can';t take the load a big prop would put on them with the extra power, does that sound about right?

[mrmurder1975]

yep. if you ran a 4s lipo and 10 inch props on a motor rated for 3s, something would give. either the esc';s or the motors. probably the esc';s. either way, the result';s would not be pretty!

[Yosser70]

yep. if you ran a 4s lipo and 10 inch props on a motor rated for 3s, something would give. either the esc';s or the motors. probably the esc';s. either way, the result';s would not be pretty!

Right I get ya. Does the same apply using say 12in props with a motor rated for 3s batteries or is it more complicated than that? Is there some sort of formula or rule for working out what batteries, motors and props will work together?

[mrmurder1975]

have a read of this. it will explain it clearer than I can. http://oddcopter.com/2012/02/06/choosing-quadcopter-motors-and-props/

another good bit of kit to have is a watt meter. with this you can find out how many amps etc your setup is pulling and if the peak current is safe for your esc';s, motors etc and will help you find the best motor/esc combination for your needs.

failing all that, just do what I do and copy other peoples configurations!

[Yosser70]

Thanks for the links mate I';ll have a good read through them and confuse myself more then go for your alternative suggestion and put up a post for advice! lol

[mrmurder1975]

lol that';s usually what I do. sometimes its easier just to ask than to try and trawl through all the info yourself. sometimes the answer is sat there looking you in the face but you cant get your head around it until someone words it differently.

sorry ive not been much help, but if I can do anything more, let me know.

not sure why im the only one trying to help you though....

[Yosser70]

No you';ve been a big help mate, those links explain it all well and if I keep reading through them it';ll sink in eventually! lol

[ChrisH]

not sure why im the only one trying to help you though....

Cos the rest of us are reading and learning? Good info!!  !

[Gaza07]

Because your doing so well 

not sure why im the only one trying to help you though....

[mrmurder1975]

Cos the rest of us are reading and learning? Good info!!  !

lol fair enough!!

[mrmurder1975]

my motors arrived yesterday. was very impressed with the props. two small bits of tape on two of them and balance was done. hubs were balanced on all of them straight from the box. makes a nice change not having to spend ages balancing props, which I hate doing with a passion!

anyway, fitted them and tested them. all seems good apart from one thing. there is a distinct metallic whine coming from one of them, not sure which one though. its not the usual ';whistle'; sound you get from some brushless motors, it has a discernible metallic ring to it. hope that makes sense.

anyone know why I might be getting this? without it, the motors coupled with simonk esc';s would be almost silent! seems worse around the mid throttle range, which is a shame as that';s the position my stick is in most of the time!

[tony]

if you cart see any thing rubbing on the motors id look at the bearings  on the shaft
and i no this is expensive for bearing grease but the needle applicator really helps loads and stops you have to take bits off to do the job

http://rc-hero.co.uk/scorpion-motor-bearing-lubrication-kit-30ml-scorpoil