spoon fed

[flying newb]

Good day to all. I have been flying for several years but stopped for a while. When I came back on the scene, everything I owned was antiquated. Mostly rotor, Ive had a couple of 3 channel planes, couple of inexpensive drones. I now want to start building some foamy planes. I started by trying to build the fly on the wall with and old mcx copter I had. It did not ever fly. I had too heavy of motors, I believe.
So I just have a couple of questions to get started.
#1 is a 2212 1400kv ok to get started with the swappable series? 8" blade ( I would like to try the Delta wing)
#2 500ah 2cell or 3cell? and is that enough battery for that setup?
I believe that will get me started. I have tons of questions and I've been thankful for the videos and forum of this very site.
However late I may be, thanks to FT for literally everything that they have put into it.

 

[quorneng]

A normal 2212 14kV is rated for a maximum of 16A. A 500mAh battery is a bit small if the motor has a prop to use this sort of power.
A 1300 mAh would be a more typical size.
The pitch of a prop makes a big difference to the power the motor absorbs/ An 8x4 or 7x6 should be ok for a 2212 1400kV on a 3s battery.
What size/weight were you thinking of for your delta?

 

[flying newb]

Thanks for the quick response.
So not just a clever nickname... I have so much to learn
I was going to purchase a powerpack option with the 2212 1400 kv motor, 30 amp esc and 8060 properller
so that is 8" with 6 degree pitch?

 

[flying newb]

Good evening, So I wanted to start with the swappable series from FT, and go from there. I believe the tiled plans for the delta has it a 660 mm.
I don't remember off the top of my head the weight they had it at and I have not done the math on my power pack and receiver pk, but I will tonight. I believe the 6 degrees on the pitch is the only variable that is not in the recommended pkg.

 

[Merv]

... 8060 properller, so that is 8" with 6 degree pitch?

A 8060 prop is, 8 inch diameter and, in theory, moves forward 6 inches with each revolution.
Higher pitch props produce more top speed and also take more watts. If this causes your motor to get too hot, you will need to reduce the watts by using a smaller diameter prop.

I do a bench test with any new prop setup. Run the motor at full throttle for 10 seconds. Then stop and check the temperature of the motor, esc and battery by touching them. Warm is OK, but if anything is so hot you don’t want to hold on to it, STOP, that’s too hot. You need a smaller prop. If it passes, try a 30 second run, then check the temperatures. If it passes, try a 60 second run. If it passes, you can go for a fly. It’s a good practice to periodically check the temperatures after a flight. What works when it cool outdoors, 70, may overheat when it gets hot, 95.

 

[flying newb]

Merv, Thanks for your knowledge. I will do that exactly. I can tell I have a lot of reading and listening to do.

 

[FoamyDM]

@Merv, would you mind if I pass this wisdom to my listeners? (www.aviationrcnoob.com)

A 8060 prop is, 8 inch diameter and, in theory, moves forward 6 inches with each revolution.
Higher pitch props produce more top speed and also take more watts. If this causes your motor to get too hot, you will need to reduce the watts by using a smaller diameter prop.

I do a bench test with any new prop setup. Run the motor at full throttle for 10 seconds. Then stop and check the temperature of the motor, esc and battery by touching them. Warm is OK, but if anything is so hot you don’t want to hold on to it, STOP, that’s too hot. You need a smaller prop. If it passes, try a 30 second run, then check the temperatures. If it passes, try a 60 second run. If it passes, you can go for a fly. It’s a good practice to periodically check the temperatures after a flight. What works when it cool outdoors, 70, may overheat when it gets hot, 95.

 

[Merv]

@Merv, would you mind if I pass this wisdom to my listeners? (www.aviationrcnoob.com)

Feel free to use any of my comments you feel others would find useful.

While we are on the subject.
I think about a transmission when discussing prop size & Kv.

Low Kv motors tend to want larger diameter low pitch props. Lots of thrust at low airspeed but low top speed. Similar to a low gear in a transmission.

High Kv motors tend to want smaller diameter higher pitch props. Lower thrust at low airspeed but higher top end speed. Similar to a high gear in a transmission.

If both setups have the same power (watts), the high diameter low pitch prop will always produce more thrust on a test stand than a low diameter high pitch prop. The low diameter high pitch prop will always have a higher top end speed. Both setups use the same power, they just release the power at different airspeeds.

In a car power is measured in Hp, for us power is measured in watts. They tell me it takes 745.7 watts to produce 1 Hp. Think about a 500 hp farm tractor vs a 500 hp race car. If you hook both of them to a plow, the tractor wins. Put them both on a race track, the car wins.

So the question you need to answer. At what airspeed do you want your power? Fast or slow?

 

[Tench745]

Feel free to use any of my comments you feel others would find useful.

While we are on the subject.
I think about a transmission when discussing prop size & Kv.

Low Kv motors tend to want larger diameter low pitch props. Lots of thrust at low airspeed but low top speed. Similar to a low gear in a transmission.

High Kv motors tend to want smaller diameter higher pitch props. Lower thrust at low airspeed but higher top end speed. Similar to a high gear in a transmission.

If both setups have the same power (watts), the high diameter low pitch prop will always produce more thrust on a test stand than a low diameter high pitch prop. The low diameter high pitch prop will always have a higher top end speed. Both setups use the same power, they just release the power at different airspeeds.

In a car power is measured in Hp, for us power is measured in watts. They tell me it takes 745.7 watts to produce 1 Hp. Think about a 500 hp farm tractor vs a 500 hp race car. If you hook both of them to a plow, the tractor wins. Put them both on a race track, the car wins.

So the question you need to answer. At what airspeed do you want your power? Fast or slow?

Well stated. I would add that aerodynamic drag can actually limit top speed significantly. To use your analogy, putting a race engine in a tractor will only do some much, just as putting a tractor engine in a race car will have limited success.
Matching the whole power system to the plane is just as important as matching the prop to the motor.