Hello,

I built a Northstar from a Balsa USA kit. I put an OS 50 Sx ring engine in it, and instead of the lead in the front I added a camera, 2.4 Ghz video transmitter, OSD etc - this extra weight in the front allowed me to take out most of the lead from the front cone. The gas tank is in the back as recommended by the design.

I originally had a 10x8 prop on it, and it was flying well, however for the takeoffs I needed a very long runaway. I changed the prop to a 10x10 thinking that that will give me the extra thrust - however I was mistaken, the plane got off the ground and just nosed in a few meters later. The damage is not much - broken tail at the ailerons pushrod exits, few cut ribs as the prop cut into the fuselage.

Before I start the repairs, I thought that I do a modification - I will lift the engine higher with abbout 1" to allow bigger - perhaps a 12x8 prop on it. The reason being that I have the same engine in a GP 40 size ultimate and it is running perfect with this 12" prop.

To do this I need to cut off the part which holds the engine and the tank, add 1" thick balsa on top of the tail portion which holds the engine, then glue the whole thing back.

I do not plan to move the engine forward or backward - I will keep it in the same position just higher wiht 1". My question is - how is this modification will affect the CG? What can I expect? The CG will move forward or backward - or it will not nove at all?

Thanks, OX.