RC India

I had made more than a 100 design of Coro and foam pushers but didn't got resources at time . so couldn't built any.
I wish to know that what are the parameters to keep in mind while DESIGNING pusher planes.
So that i know to get further in designing or stop.
Thanks

WHILE desinging a pusher plane everything is as usual as like a tractor

the major difference is

the thrust line:   its going to stay above centre of gravity; centre of pressure; aerodynamic centre too....

and you will be limited by prop size.... so u ll be forced to higher kv motor and lower size prop

If you want to build a trainer corro pusher plane then you can build  Extreme sports pusher trainer. Plans available on rcgroups.com.

I use to pass the thrust line through cg .
But that increases angle of decelence.
How to deal with that

Angle of decelence  ???

sir actually you should not do that and you  ll not be able  to do that

generally in pusher type planes the motors are at top...

to compensate your pitch down moment you ll be forced to coincide the thrust line with c.g along the longitudinal axis

but you cant do that... if u want to do that you need to place your battery at top of the plane as far as possible....

other simple thing you can do are

      (i)   always trim the elevator for a pitch up moment
     (ii)   if you are using flat plate  as horizontal stablizer place it at some degree
     (iii)  use a unsymmetrical aerofoil for the horizontal stablizer

but you need to counter few problems in the above solutions

the common thing for all the three is the distance between the cg and horizontal stablizer must be greater comparing to tractor inorder to create a huge moment with less force

the first one    "always trim the elevator for a pitch up moment"

since the elevator is sacrificed for solving pitching problem.... you may not be able to use it for pitching and climbing

the second one  "if you are using flat plate  as horizontal stablizer place it at some degree"

since it is placed at an angle already it may reach  stalling soon

an example of this technique
http://scienceguyorg.blogspot.in/2013/07/stol-aircraft-i-learned-something-new.html

I think I did some glide tests with proper ballasted cg
And that concluded   that those designs actually worked     though some had a limitations of max 10" prop
But I think that's large enough for those < 1kg planes AUW.

actually sir...  when you does a glidetest there is no thrust

if you post some pictures it ll be great

Yeah true said but after that realisation
 I laughed a lot     can't post pics using a WAP connection

i can do an  help sir... if u give me details about ur plane i can make a 3d diagrm using solidworks for u

thanks dev.  its much simple. it has very thin wooden. tail boom and frontal part is all the volume . spans 1200mm and lengths 900mm and fuselage is 300mm high . 

sir fuselage is 300mm high...thats too much...pls tell the problem you are using

http://flitetest.com/articles/Motor_angles_for_pusher_planes

fuse is that high because to accept the 1045 prop .

the plane continously goes down... am i right?

yeah when powered.

made an 22° up thrust
 moved the wings as high as possible to minimize the down pitching moment arm

dont do that sir... it will affect your forward flight velocity which will straight away decraeses lift.... use a clarky aerofoil for the horizontal stablizer and place it at 1 to 2 degrees... and then trim the plane... the problem will be solved

there is no problem when I.  decrease the upthrust to 4° and moved the wings to the height of motor.    looks bad fly's cool

will soon buy a rx to test it real rc.

Bumping a old threat
made several pusher planes each chucky.
What works best is 2 to 8 degree thrust angle  .
Although 0 thrust angle works but needs flaps down.