Twin Otter CG help

[Oscar]

Recently I bought an electric Twin Otter from someone at the RCC classified forum.  The seller bought it from someone years ago but never flown since.  The plane was sitting at the garage for number of years collecting dust.  I know it has two 40a ESC and it runs on 3S Lipo.  However, I don't have any info on the CG.  I do know it is around 84" wingspan and it is a 5 Ch (T/A/E/R/F) plane. And the plane is based on Ivan plan ()  I replaced the ubec and the 72mhz R/X with CC 10a and Spektrum R/X.  The servo and the motor seems okay

I remembered in the build class, somone told me the CG usually it's on the main spar of the wing.  But I am not certain. 

I asked Frank earlier and he suggests to post the question in here. 

Any advise would greatly appreciated. 

[Michael]

On the spar.

[Skyking]

Ivan Pettigrew
He is a modeler in British Columbia who designs good aircraft that are light and fly well.
Google his website.
He has a lot of planes that fly off water.
I have the plans for his 83" sea cat which is a scale Catalina.
Ken

[Candu]

Nice! On the second last photo, what are those white things? I see one has a push rod connected, but what are the rest used for?

You may want to try one of those CG calculator on the web to get a rough idea where the CG is...

[Oscar]

Thank you everyone for the suggestion.  I looked up the internet for Ivan Pettigrew.  Wow!  He is a well known modeler in the RC community.  The white push rod are the ailerons and the flaps.  May be it's for the scale look??