building to a CG, or, change of CG when covered

[J.N.]

Sorry if this turns out to be like asking how long is a piece of string but it is a result of reading threads on keeping the all up weight of a model to a minimum. 

 

My Flair Magnattilla is complete and ready to be covered  (I may use Solartex).  

Is it possible at this early stage to determine what the likely effect on the current point of balance will be after the covering has been applied.

 

Or put another way.

As a general rule, is it possible to work to a point of balance when building; such as where to fit servoes and RX battery, or choosing heavier/lighter undercarriage wheels.

 

Thanks

[TonyS]

Hi Jeff,

I'm no expert but "keep it light" is the mantra for modelling.

On that basis you've really got to work out where all the essentials go as you build to end up with the right CG. If you just build it then worry about adjusting the CG the the only way to fix the problem is either move the battery (if it's electric) or other moveable bits which can be limited, or add weight which you really don't want to do. 

Solartex isn't that heavy though so if your CG is OK before applying the covering then it's not going to be far off when you're done. I've found from my limited experience that models are quite forgiving if the CG moves forward but don't work well (if at all) if it moves back.

T 

[Erfolg]

My own method is to build as per design.

 

As part of the build i tend to see as fixed are the structure and engine/motor.

 

Move able, servos (except those in the wing, which are normally behind the CG) batteries/llipo, rx, ESC. So these are permanently fitted last, although i do consider where they can go during the build.

 

If after fitting the servos etc, to obtain the best CG position. There is no option Pb, Lead, for me almost a swear word. Yet it can be the models "Guardian Angel". As nothing kills a model quicker than a rearward CG. A foreword CG tends to be tolerable, although to far forward and those troublesome handling issues emerge, of languid, initially sluggish response, which once started want to continue.

 

Erfolg