Looking good down there :-)
As regards the CG - I tried 7 different positions yesterday and finished up with the following. (I moved the battery all around the plane to do this)
Mine likes the CG to be right on the center of the wing tube. It snaps better, stalls into the spin very cleanly (No floating around). The rolls are just as easy andi t feels better to hold a bit of down in inverted flight.
Please note that when I say on the center of the wing tube, I mean with the wing off.
It is so much easier to use a reference point on the fuselage with the wing off. For example, if you change the rudder you can get back to where you were without assembling the whole plane. The wings don't change. They do move the CG back a bit, but it is the same amount every time.
Regards,
Eric.
ORIGINAL: Bogan
Been working frantically on my Impact over the last 6 weeks.
Test flew it a week ago, and have been out a number of times since. All going very well so far, with 160DZ in the front. No signs of any rudder problems (touch wood !!!). I've been watching this post through the whole build, and pretty much took on board all of the mods listed. I had to rehinge the rudder to make it removable, and now that its in the air, I'll make a balsa one to remove some tail weight. CG is about on the back of the wing tube, if anything I will move it slightly foward. Been great weather for trimming this week, so I won't really be happy with the CG until I fly it in a howling gale.
I'm running the wing and stab a zero, as best I can measure. My meter is a Robart one, so unable to measure 0.25, but from my trim flights so far, I have no Elevator trim and the downlines are perfect. If anything it could do with a touch of upthrust. I have both wing and stab adjusters, so can tweak these. I'm slowly adjusting the wings to get the aileron trim sorted out, but there is only a fraction of trim required to keep it level.
Needs more right thrust. For now I've got a small amount of right rudder mixed with throttle to sort this.
Its not much lighter than my PL Smudge which was right on 5Kg, but for some reason it feels a lot lighter in the air. Bigger wings ? More fuse volume ... dunno, but certainly happy with it so far.
FB