prop shaft centre line?

[eindecker]

Can anyone explain what would be the outcome,of setting the prop shaft above and below the intended thrust line exit point,as i have a strange feeling that a model i am working on,does infact have the exit point set to low,and i would just like to have some idea on what i might expect on first flight,before i adjust mounting plate

Many thanks inadvance

Eindecker:)

[steve lewin]

If you mean that the propshaft is pointing in the right direction but the motor is simply mounted lower or higher then there will be very little difference unless it in a huge amount out.

If you mean the motor is set at an angle so that the prop shaft comes out incorrectly then you have problems. See the many discussions on downthrust, thrust lines etc.

Steve

[Tony Oliver]

There's not usually much difference as far as the flight characteristics of a model are concerned.
In effect, a higher thrustline will tend to pull the nose down slightly, and vice-versa. That's assuming a conventional sort of tractor prop/high wing layout. If you think of it as a leverage effect you'll get the right idea.
The more obvious effect as you suggest, is the aesthetics of the propshaft coming out in the wrong place or the wrong angle.
There's not much scope in most designs to get it wildly wrong, so you shouldn't be unduly worried.

Tony

[eindecker]

Thank you for your replies.

I would guess that the shaft is about 1 cm to far down,but thats a guess,the plan is not very clear on the correct exit point of shaft,i guess the only way is going to be to test fly!!!,all side and down thrust are spot on,so it will just mean shimming motor mount up or down.if the need arises.

Thanks again

Eindecker