Help! Could the Emax XA2212 be a good choice in general?

[mbyvz]

Hello,
I am very new to this hobby.
The Emax XA2212 has 1400 kv and 980 kv options.

Can I make slow flying suitable models such as simple cub, Bushwacker with this engine?

With which kv value would it be more advantageous for me to use it on different model airplanes?

I currently have an a2212 1000kv cheap and simple engine in my hand.

Would your advice be to use it until it breaks, or should I throw it in the trash and make my first flight with a quality engine like emax?

I need even the slightest information you can give. tips, general information, advice, experience, anything you can share.

I haven't flown it yet, but I have completed the construction of the simple cub as my first airplane. (all inclusive flight weight 600 gr)

Thank you in advance...

 

[Foamforce]

A standard cheap 1000ish kv 2212 motor is just fine for any plane that recommends a B pack. Since this is your first plane, I would recommend sticking to that and a 10x4.5 or 10x4.7 slow fly prop, which is usually what comes with those motors. Going with an emax might slightly increase your power but it’s not necessary. Stepping down to a 980kv won’t make any real difference. Stepping up to a 1400kv means you’ll need a smaller prop. You’ll get higher speed but you won’t have as much immediate thrust for takeoff or recovering from mistakes, so stick with the 1000kv.

Good luck and don’t pull up too hard the first time you try to take off. Easy does it to avoid an immediate stall!

 

[Merv]

...Would your advice be to use it until it breaks...

Yes, use it until it breaks.
The 1000kv is prefect for most trainer planes. It should provide plenty of power at low speeds, giving a new person more time to react before the plane hits the ground. And you will hit the ground, it's all part of the learning process all of us have gone through. After you learn to fly you can upgrade to a larger, faster motor.

Remember the FT moto: Build, Fly, Crash, Repeat.

 

[mbyvz]

A standard cheap 1000ish kv 2212 motor is just fine for any plane that recommends a B pack. Since this is your first plane, I would recommend sticking to that and a 10x4.5 or 10x4.7 slow fly prop, which is usually what comes with those motors. Going with an emax might slightly increase your power but it’s not necessary. Stepping down to a 980kv won’t make any real difference. Stepping up to a 1400kv means you’ll need a smaller prop. You’ll get higher speed but you won’t have as much immediate thrust for takeoff or recovering from mistakes, so stick with the 1000kv.

Good luck and don’t pull up too hard the first time you try to take off. Easy does it to avoid an immediate stall!

My knowledge about propellers is also very limited. as far as I understand, the diameter is related to the weight that the engine can lift. pitch is about speed. is this information correct?

If this is correct information, when choosing a propeller, is it more successful to choose an engine with a thrust force equal to the weight of the aircraft, or an engine with a thrust force greater than the weight of the aircraft?

As for pitch, is there a noticeable difference between 10x4.5 and 10x4.7, which you gave as an example? Is there a difference in speed? ease of control? what exactly do you think it is?

 

[mbyvz]

Yes, use it until it breaks.
The 1000kv is prefect for most trainer planes. It should provide plenty of power at low speeds, giving a new person more time to react before the plane hits the ground. And you will hit the ground, it's all part of the learning process all of us have gone through. After you learn to fly you can upgrade to a larger, faster motor.

Remember the FT moto: Build, Fly, Crash, Repeat.

how does 1000kv generate more power at low speed? logically, doesn't the greater the engine speed, the more power it produces?

Can you explain a little so that I can understand this topic?

 

[quorneng]

mbyvz
The power an electric motor can produce is proportional to the voltage applied to it and load attached to it but it all has to be within the design limitations of the motor. Exceed the voltage/load limit and the motor will get hot and soon fail.
Any given prop will exert a particular full power load on the motor. Too 'big' a prop can over load a particular motor.
The load a prop creates is proportional to the product of diameter and pitch but the load does decrease as the planes airspeed rises. At some airspeed the prop will no longer create enough thrust to overcome the drag of the plane so it will go no faster For a particular motor and voltage the coarser the prop pitch the higher will be the top speed achievable but you have to keep within the maximum amp limit of the motor. So for your question a 10.4.7 will require a bit more power (amps) but the difference will be small. It could only be a problem if the 10x4.5 was already at the motor's amp limit.
In general a larger diameter fine pitch prop will for the same motor power generate more low speed thrust. A smaller diameter coarser pitch prop will make the plane go faster but it still has to produce enough thrust to fly the plane adequately. There are limits to how far you can go for any particular plane/motor/prop combination.
To begin with the best advice is to use a recommended prop. Until you have quite some flight experience with the plane it is unlikely you will be able to tell the difference in the way it flies by changing the prop and in doing so you might over load and wreck the motor and/or its speed controller. Expensive!

 

[mbyvz]

mbyvz
The power an electric motor can produce is proportional to the voltage applied to it and load attached to it but it all has to be within the design limitations of the motor. Exceed the voltage/load limit and the motor will get hot and soon fail.
Any given prop will exert a particular full power load on the motor. Too 'big' a prop can over load a particular motor.
The load a prop creates is proportional to the product of diameter and pitch but the load does decrease as the planes airspeed rises. At some airspeed the prop will no longer create enough thrust to overcome the drag of the plane so it will go no faster For a particular motor and voltage the coarser the prop pitch the higher will be the top speed achievable but you have to keep within the maximum amp limit of the motor. So for your question a 10.4.7 will require a bit more power (amps) but the difference will be small. It could only be a problem if the 10x4.5 was already at the motor's amp limit.
In general a larger diameter fine pitch prop will for the same motor power generate more low speed thrust. A smaller diameter coarser pitch prop will make the plane go faster but it still has to produce enough thrust to fly the plane adequately. There are limits to how far you can go for any particular plane/motor/prop combination.
To begin with the best advice is to use a recommended prop. Until you have quite some flight experience with the plane it is unlikely you will be able to tell the difference in the way it flies by changing the prop and in doing so you might over load and wreck the motor and/or its speed controller. Expensive!

thank you for the experience/knowledge you have generously shared.
regards

 

[Merv]

how does 1000kv generate more power at low speed?...

First, I should have said thrust, not power, there is a difference. In liquid fuel engines power is measured in Hp. In electric motors power is measured in watts. A tractor and a race car can have the same power, Hp, but at vastly different speeds.

Regarding kv, think transmition. Consider two motors, one 1000 kv, the other 2000kv, both have the same watts. The low kv motor with use a larger diameter low pitch prop. It will produce a lot of thrust on a test stand but have limited top speed. Similar to low gear in a transmission. The high kv motor will use a smaller diameter prop, have less thrust on a test stand but much higher top speed. Similar to high gear in a transmission.

It takes the same power to move a lot of air slowly as a smaller volume of air fast. The question is at what speed do you want the power.

 

[mbyvz]

First, I should have said thrust, not power, there is a difference. In liquid fuel engines power is measured in Hp. In electric motors power is measured in watts. A tractor and a race car can have the same power, Hp, but at vastly different speeds.

Regarding kv, think transmition. Consider two motors, one 1000 kv, the other 2000kv, both have the same watts. The low kv motor with use a larger diameter low pitch prop. It will produce a lot of thrust on a test stand but have limited top speed. Similar to low gear in a transmission. The high kv motor will use a smaller diameter prop, have less thrust on a test stand but much higher top speed. Similar to high gear in a transmission.

It takes the same power to move a lot of air slowly as a smaller volume of air fast. The question is at what speed do you want the power.

It was a very enlightening narration. Thank you very much.