Scratch built model
 

Hi
I am building a 3D model for OS 50 Sx. Just started by drawing up plans and now I have come to the covering stage. But I dont know if it has proper proportions!!

length: 58"
span: 56"
wing area: 952 sq. in incuding ailerons
stab area: 168 sq. in including elevator
engine thrust: 2 down, 3 right
airfoil without aileron: 13" chord, 2.9" max thickness at 4" behind LE. part behind spar is very slightly curved
engine centre line at firewall is at same level as stab.
centreline of wing LE is about 4.5 cm below the stab line
aprox 0.25 deg is the wing incidence

how does this look?? workable?

thanks

Vikas

RE: Scratch built model
 

sounds right on, have you got any pictures or a drawing, that would help a lot

RE: Scratch built model
 

please post some pictures if ytou can!

RE: Scratch built model
 

Engine thrust may need to be changed. I would not put in any down thrust. Right thrust at 3 degrees may be too much I normally start with 2 and adjust. Trim charts for pattern planes sometimes indicate upthrust for clean down likes. What is your reasoning for the wing incidence?

EXCAP232

RE: Scratch built model
 

Thanks for the replies.
I dont have any photos now but will try to post some. I did start by making plans but the end result is somewhat different!

EXCAP232, I will reduce the right and down thrust and then adjust after flying. I have not had much experience with 3D models as normally I fly pattern (just made one Millennia some time back) but I see in almost all plans that there is some wing incidence. So I decided to give a bit of it. Do you think the incidence shouldn't be there? Why? I think the plane will need a good amount of tuning after flight.

What do you feel about the airfoil?? Looks OK?

Thanks