Determining thrust line;

[Basil]

While trying to fill some time I have turned to a high wing  airframe given to me by a friend thats needs a bit of work. The original part of the nose, forward of the front former  is missing for the most part. From what remains I can roughly determine the nose length , but to determine the motor shaft centre I feel may not be entirely accurate. 

I am trying to work out where the engine should be mounted. I am assuming that the 'Thrust line' will determine the centre line of the motor shaft. Assuming I am correct how do I go about deciding the correct thrust line(where to mount the engine.)?. I am using an electric motor.The basic design I would suggest is of a trainer type, looks to be of stable proportions.

Have I bitten off more than I can chew?.

Bas

Edited September 3 by Basil

[Peter Jenkins]

Bas, if you are a complete beginner to model aircraft building and flying my short answer would be "Yes".  Without knowing more about your capabilities as both a builder and a pilot it's an impossible question to answer.  If you are still in the very early stages of learning to fly, then definitely not a good thing to have to deal with a potentially seriously out of trim model.

[Martin Harris - Moderator]

TLAR (that looks about right) will probably suffice.  Get guidance from any similar models (or plans - outer zone would be a good start) that you can refer to. The higher the thrust line, the less downthrust will be required. When test flying, remember that thrust line has no effect when the power is off so reducing throttle will tame any wayward behaviour. 
 

It may be advisable to enlist help with initial test flights or trimming if you’re relatively inexperienced. 

[Mike T]

I agree with Peter that it's an impossible question to answer, but not for the reasons he's given.  You simply have not given enough information.  Do you know what aircraft it is and/or have you attempted to find out?  Try posting up a few pictures.  In short - throw us a bone here!

[Paul De Tourtoulon]

Take a look at the plans on the outerzone, find one that looks like yours and use that as a starter.

[Basil]

Thanks for your replies. I will not pursue the matter any further.

Bas