Large Model Association Forum

I posted back in january regarding my Hannibal. I am just about ready to fly her but am a bit concerned regarding the CoG.She is fitted with a Super Tigre S2000 25cc. All of the servos are fitted and set up,also the receiver and battery.I know the CoG is on the main spar,but i have to add 220grms of weight to get the balance right. I have moved the battery as far back as i can,but still need the weight.I could probably add a bit less weight if i could find somewhere at the tail end to put them.Any advice would be much appreciated. Im hoping to fly this weekend.

Not to sure what you want anyone to say.
We have 2 of them in our club, both with 26cc petrol engines in. The one I know best has a Z26 in it.I bought it for the present owner at the Nats last year. Servos and battery are up front and the CG is perfect.
If you are having to add all that weight at the rear you must have done a great job in weight saving I guess.I would think a ST 25 is similar in weight to the petrol motors if not a bit lighter .
Could you not move all your radio gear rearwards and not add any lead to the tail.

Si

I have tried that but still have to add the weight. Silly question but is the main spar the one just behind the leading edge?Im pretty sure it is?

The cg on the one I set up was at 30% cord and its so stable its untrue. Where the spar is retaliative to that I cant remember.
I would be more than happy to move it back further than that.

Si

Peter, in very "general" terms, the main spar is often at the thickest part of the wing when viewed end on. This also "generally" corresponds to Simons 30% chord position. So you can see from this, its not the one just behind the LE but "generally" one third (30%)of the way across the aerofoil, heading from the LE to the TE.
I hope this is as clear as mud.

i dont want to hijack the thread but...

would a zenoah22 with reduction drive fit in the front of a hannibal??