When determining the c/g (aside from personal preference) does the canalyzer figure into the MAC and c/g computations?..Case in point: On my Caelus, moving the c/g from the recommended starting point of 7.5 inches from the leading edge aft to 9.5 inches does not seem to have an appreciable affect on flight performance, at least to me. Does the canalyzer dampen the c/g sensitivity?...Thanks.

Gary

I would say no, but im no aeronautical engineer , you could fly it with out the canalyzer and see.

Guys,
Is the 190mm (7.5") a good starting point as the manual shows?

I started there, but am at 9.5 from the root leading edge now.You might get a few more responses on the Caelus thread.

Gary

Depends on how much yaw stability you want. Also depends on how much mix you want to dial into the set up.

I don't have the plane's parameters so not certain but it sounds like the fore CG is fairly close to the 25% Mac region. At this location the model probably has a more locked in feel. With the aft CG, pay close attention to the directional feel of the plane and compare that to its fore location.

Do the same for knife edges, both sides, both locations. The smaller wing will help reduce amount of mix you need for straight flight in knife. Ideally you want no mixing of rudder to elevator.

If the model has a roll tendency with applied rudder, the wing dihedral isn't precise. Rather than building a whole new wing if you don't want to mix, you will be able modify the dihedral effect by modifying the smaller wing. That is adding anhedral or dihedral to the smaller panel, depending on what the plane needs. This is one time when a small rud to ail mix may be necessary but if it's more than a few %, some unwanted subtleties may creep into certain advanced loop-roll combination maneuvers.

Its all all about the trim you like

Thanks, Matt
There is no roll coupling noticed with rudder application. On left rudder k/e, no elevator mix is needed. On right rudder, about 7 to 10 degrees down elevator is needed. Low right rudder input on level flight requires no mix in either direction. I have the mix offset for right rudder set to about 50%. I flew yesterday in 20-25 mph cross-winds, and the aft c/g may have been causing it to wander a bit...or could have been the gusty winds.... I may just move the c/g forward a bit in windy conditions and trim for it.

Gary,
Have you checked wing and stab incidences? Don't accept the factory settings. Start with things verified true then go from there. Also make sure ailerons and elevators track true

On pitch couple, did you mean % rather than degrees? 7 to 10 degrees down is huge. If the model pitches up with top right hence needing that much down ele, you may want to reduce incidence of the left panel about .2 degrees. Assuming that the plane has wing adjusters of course.

you want calm conditions for better eval.

Stab and wing incidences are good. Stab at roughly 0* to level the elevator, wings are set to 1*. Trying to wrap my head around changing the left wing incidence to cure a right rudder pull to canopy makes my head hurt...lol

Were incidences checked against each other? That's what I meant. On your flat surface, and with the fin vertical to the surface, check LE and TE heights precisely, with a height gauge.

Remember the simple 1-1-4 rule ( I came up with it many years ago, btw, and I put it on the Nsrca website). One degree is equal to 1/4" difference in 14". A 14" chord is at 1 degree when the difference between LE and TE incidence measurement is 1/4". The rule applies to thrust angle for example, wher you measure prop tip difference.

Top rudder blanks out the components that are on top a considerable amount. Components flying on the bottom become more effective.

Or you may increase left stab incidence by ..2 degree. You may need to adjust both the left wing and left stab. You should reduce the mix but may not eliminate it altogether with these trim changes. You may get to a point where more change starts to screw up the overall flight envelope. Hope that explains it

Matt, I set them initially the same, using a digital angle meter to .1 degree. Then about one turn of one of the adjusters to eliminate minor aileron trim. Thanks.

An interesting note to add:. At the last contest, it was called to my attention that I did not seal my aileron gaps. (I do on my fast planes). I did so last week and found that I had to remove about 10% on the rates for aileron. (Roll rate was now too fast) Also the elevator sensitivity went up, and I did not seal those gaps! It was like flying a different airplane, not in a good way, Either the sealing affected the trim to some extent, or the turbulence by having gaps softened the elevator response. IDK. I was able to move the C/G forward a bit to soften the elevator up, and that also helped with tracking. Trimming is so much fun.