• This site uses cookies. By continuing to use this site, you are agreeing to our use of cookies. Learn more.

Heavier planes?

Blaze_Sw

Junior Member
#1
Hi, I'm kinda new to the hobby i have gone through the super cub and now I fly a pz spitfire. Since I found this awsome show and comunity my desire to expand my hobby have grown. I'm planing to build a ft racer but I live in sweden so it will probably be heavier than dollar tree foam. So the question: what kinda motor do i need? preferably a turnigy, heard good things about them. All the number are so confusing on electric motors so if someone have a link to explaine this or the time to write it down themself It would be very apriciated.
 

rcspaceflight

creator of virtual planes
#3
Turnigy usually has numbers like 2826 on them. The 28 is the diameter of the motor, and the 26 is how deep the can (the part that holds the magnets) is. The numbers are mostly for comparing motors. They don't really tell you the performance of them. Obviously, the bigger the motor is, the more powerful it is in general. I'm sure you know what KV is and what it means. It's how fast the motor spins.

The best place to start is to pick the prop and KV you want. A static thrust calculator like this one: [link]personal.osi.hu/fuzesisz/strc_eng/[/link] : will help to get an estimate at how much pulling power the motor will have with any given prop. Then find a motor that has the KV you want and can handle the prop you want. Usually going with what other people have said about the motor on the hobby store's website is the best info.

It helps to have an estimation of the total flying weight of your plane so you know about how much thrust you want. You don't need more thrust than what the plane weighs. I don't remember what percentage is the minimum is. But you can always use less throttle, so it's better to over power than to under power.

EDIT: I should note that the calculator I linked asks for the RPMs. You have to multiple the KV of the motor by the volts of the battery you'd use to get the RPM.
 
Last edited:

finnen

Senior Member
#4
As a side note from another Swede, what are you using as foam material? I have used Ebisol, that you can buy from any Ebeco-retailer, all over Sweden, just need to call them and order, 10 boards minimum, I payed 550 SEK: http://www.ebeco.se/aterforsaljare

I haven't weighed it, but it works fine for the FT-planes.
 

Blaze_Sw

Junior Member
#5
Thanks for the advise i' ll get the foamboards delivered today. I'll build it with just the aileron servos installed and then weigh it.

Finnen i bougth kapa from staples. Hope it will work. Kinda expensive but they deliver to your door free of charge.