Originally Posted by Finnspeed
My Sirius Eleven flew today and my first impression is that it flies extremely well. It is not completely dialed up yet but getting there. The 225 mm CG is very close to the optimum in my opinion but it is a matter of taste and flying style. I would actually try to move it just a bit further back and not forward.
Now you have to pull a bit during level flight and push accordingly when inverted. This is the correct behavior for F3P but I might try how it feels if the need to work the elevator is minimized. I won't go all the way to 3D CG though.
Knife edge is very stable with a slight tendency to pull towards the cabin. I think this is either due to my elevator trim or the small fins that are attached to the ailerons generate enough lift to create this effect. This lift is not completely symmetric because the fins are on the underside of the ailerons only.
I had the chance to fly AC Glenn's Sirius the other day in the armory, and it flew very well. I noticed similar things to what you mentioned above, but I'm very confident a further aft CG would help. Try it if you get time and report back on what you notice it changing.
A further aft CG will make you carry more down elevator trim (or less up), which will help the pulling to the canopy issue while on knife edge. I also prefer a more neutral airplane for F3P (but not in larger precision models), so moving it back would help there too.
I haven't gotten to try AC's with a further aft CG, but I'm pretty confident it would help.
Overall great flying airplane!