what kv would be better for speed, height, handling, power efficiency and any other advantages or disadvantages?
DemonGodS:
what kv would be better
Somewhere down in the 0.01 kV I'd say, that is if you really meant kiloVolts?
Kv is dictated by the required rpm of the motor and the voltage of your battery supply.
Rpm is normally in the 1500 to 2000 range for a quad.
Does that mean that in the world of quadcopters, "kv" doesn't mean kiloVolts?
It means a thousand per volt, RPM.
Boardburner2:
Kv is dictated by the required rpm of the motor and the voltage of your battery supply.Rpm is normally in the 1500 to 2000 range for a quad.
It totally depends on the size type and pitch of the props, the supply voltage, the thrust required
and the degree of aerobatic performance wanted.
I've got a quad with Kv 15000 rpm motors or so, but its tiny.
There are calculators for this kind of thing on the web, and specialist quadcopter forums will be a
much better place to hunt for this kind of knowledge. You will either need to know the parameters I've
mentioned already, or else be prepared to get props and power pack to match the motors. The whole
powertrain needs to be matching to get a workable system, there is not much wiggle room.
MarkT:
The whole
powertrain needs to be matching to get a workable system, there is not much wiggle room.
I agree, until you have experience its best to go with an existing frame and design.
Then try tuning it later by swapping bits.
It is a balancing act though.
DemonGodS:
what kv would be better for speed, height, handling, power efficiency and any other advantages or disadvantages?
What size frame are you using ?
Frame size isn't relevant. Total mass is relevant.
so i found some 935Kv motors on amazon... should i be getting higher KV motors for my quad? i havent bought anything yet im still researching what parts would be best...
MarkT:
Frame size isn't relevant. Total mass is relevant.
Frame size can dictate the size of prop.
OP has not said what he is trying to achive.
Drone with high longevity.
Racing drone with high performance with short flight time.
Very different requirements.
DemonGodS:
so i found some 935Kv motors on amazon... should i be getting higher KV motors for my quad? i havent bought anything yet im still researching what parts would be best...
Sounds like you are a newbie.
Do yo have experience with model flying.?
If not i suggest you start with fixed wing aircraft to learn basic controls, its not easy.
What are you trying to do.
I was thinking starting with quadcopter would be easier than fixed wing.
Also..... the symbol is actual k with a subscripted v.
The symbol 'kv' is stupidly written like that due to no subscript feature.
It should just be 'k'.... which is nothing more than a proportionality constant that relates motor output shaft angular velocity with input motor DC voltage. Eg..... 10 Volts input....... X radians per seconds output...... so k = X/10 rad/s per Volt. Or 15 Volt input... X rad/s output.... so k = X/15 rad/s per Volt.
But in the UAV world..... the units of k will just be converted to units of RPM per Volt.... rather than rad/s per Volt.
Manufactures numbers rarely mean much in hobby motors. Look for thrust tests and motor/ prop combinations that will give you the thrust you need at a power level you find acceptable for your batteries and esc's. Thrust should be at least twice the weight. If your quad is 1kg you should have 2kg thrust (500g per motor).
Say you had two outrunners of the 2212 size.( 22mm across the rotor and 12mm high), one was 1000 rpm/volt (Kv) and the other 3000Kv motor.
At the same power levels the 1000Kv motor would produce more torque. The 3000kv would be spinning faster. Why you would wan't one or the other has to do with flight characteristics you want and efficiency. And available space to swing the props.
The design and pitch of the prop can make a huge difference in either case.
This is a generalization and very basic. There are tons of pages on motor Kv and prop choices on rc sites.
Southpark:
I was thinking starting with quadcopter would be easier than fixed wing.
When a model flies away from you left it left and right is right.
Flying towards you they are reversed.
You have to get that 'wired' into your brain first.
Quads are more difficult to see what direction they are flying in.
A large slow moving fixed wing is easier in this respect.
Quads, i would suggest you start with one of the standard frames for which the design information is available.
They are generally made by hi tech means / materials which are not easy for home build.
You could probably make one from balsa but first crash and its gone.
Modern stuff is much more robust.
DemonGodS:
so i found some 935Kv motors on amazon... should i be getting higher KV motors for my quad? i havent bought anything yet im still researching what parts would be best...
There is no point whatsoever buying things before you've worked out what you need,
that's a recipe for wasting money on parts that are not going to be appropriate.
MarkT:
There is no point whatsoever buying things before you've worked out what you need,
that's a recipe for wasting money on parts that are not going to be appropriate.
i haven't bought anything yet and i wont until i know what i need... thats what i was trying to say in that message
Pick your frame first.
The size and weight of that will dictate prop size motor size and battery size.
You need a full mass budget for any aircraft, then try and find parts that are within those
limits (and for motors are powerful enough). Without a good idea of the total mass you
can't select anything - and typically you will have to rework the plan in the light of the
masses of available components. Don't forget any payload in the calculations.
When you buy a frame they normally come with recommended parts to get you going.
From what i see after that its a case of experimenting and tweaking.