rva1945

Hi:

I aim to build a RC ultralight. I will use what I have so far: a 10x5 wooden pusher prop and a 1000KV brushless motor and its ESC.

I have built a FliteTest Simple Cub so far (and it flies pretty well!). My chosen design is this one, the Rans 12 Airale (just because it will be easy to hide the batt and electronics):

https://upload.wikimedia.org/wikipedia/commons/d/dd/Rans_S12_(D-MQQQ)_04.jpg

what about building the wings with a good dihedral and use only rudder?

Is there any section where I can find info about RC ultralights?

Thanks, Robert.

ron_van_sommeren

Can't help you with plane design, but ..
Motor max. current and max. power?
Battery voltage?

Note that Kv says absolutely nothing about max.power or max. current a motor can handle, or about max. torque. A 1:1 train motor and the motor in your toothbrush can have the same Kv.

It's all about what the motor wants/tries to do versus what the motor can do.
Kv matches rpm and voltage, there's nothing more to it.

• Kv and voltage determine how fast motor wants/tries to run
  (rpm_noload = voltage × Kv).
• Rpm and prop determine torque, which in turn determines current
  (current = torque × Kv, in SI units!).
• Max.current and power determine whether that battery/motor/rpm/prop combo can run without going up in smoke.

Prettig weekend Ron
• Without a watt-meter you are in the dark ... until something starts to glow •
• e-flight calculators • watt-meters • diy motor tips&tricks • Cumulus MFC •

rva1945

I will use 3S lipos, 1300-1500mAh. I measured the motor with a 9x5 prop at almost 800gr.