All right I need a bit of help here!

I have a mojo 40 ARF that climbs while inverted and Pulls to the canopy while in knife edge. The pulling to the canopy would indicate a fwd CG and the climbing while inverted situation would indicate a classic tail heavy airplane. Anyone had this before.

I am going to move my CG back a bunch and give it a go and see how it works since it doesn't fly like its tail heavy. What I mean by that is it isn't real sensitive on the elevator and I have large throws. What I want is perfect KE. I think that if I move the CG back a ways AND adjust the ailerons I will improve both.

Anyone fixed this situation before????

Dave

If it climbs when inverted then its TAIL heavy. Generally, when it tuck towards the CANOPY in a KE then its NOSE heavy like you said. I would normally set my CG by flying inverted and any KE issues be tweaked by moving the CG a bit and eventually mix it out. Looks like you have to mix out the coupling in KE. Being a profile might your wing incidence be out? Just a suspicion. You will hardly find 'perfect' KE planes. I found the best so far to have been the EF Extra 300 EP and my Fliton Extra 330. Both will give you an amazing KE once you set the CG right in the sweet spot. I do not need any mixing.

Thanks for the repley, you sound like a guys who knows his stuff.

Here is the catch. The plane is known for hands off KE ( more or less) and I need a bunch of rudder to do it. I used to have another mojo that was more tail heavy and flew much better KE so that is why I think I have compensated its inverted flight in an attempt to correct the KE by raiding the ailerons to far.

I must admit that I hope your wrong and the CG change fixes it. Although I never seam to be right.

Thanks again,
Dave

Check the wings for washout

also do some vertical climbs to check the up/down thrust. Adjust as needed, then go and check the inverted flight and KE again.

My EF Edge needs down ele to hold inverted, and tucks to the belly in knife edge. I added another 1/2oz to the tail last week and it has improved, now balancing approx. 1/2" behind the spar and needin less ele to hold both.

I know this goes against the theory, but from the above I would try moving the balance forward slightly till the airplane flies neutral inverted, then try knife edge again.

I agree with tIANci says about tail heavy and KE, also with you about him knowing his stuff.
Rc universe is great to learn about problems and help without costing grief or money. Thankx to all that help.

3DAP

tIANci,

I have a Saito 100 that needs a home. I am pulling gear out of vetor flight extra 300. I hoped it would
be a good 3d kit despite reading several posts about it being a sort of lemon. Any way it is going to be
a wall kit now. It has a terrible tendency to snap when over controlled at high speed. I have lateral
balanced it and tried everything to get it to preform. I am looking at Fliton edge 540 or Fliton extra 300.
Which one will do it all. I have been reading a lot of your posts about Extra 300, it sounds like a no
brainer. Does it need some building love or go with the Edge?????? Thankx

3DAP

have you check aileron neutral position? they may be reflexed (both up) or flapped (both down)

I say check this because inverted climb means tail heavy BUT pitch to canopy means nose heavy, so I think there is another variable

hope this helps

Just for more data points. How about elevator trim? Are you flying with up trim, down trim? If so, how much trim do you have in degrees or inches?

Hey guys, I got my mojo 40 figured out! I forgot which way I adjusted the ailerons but that fixed the pitching up in inverted flight and a bit of mixing for KE has nearly fixed that to. A little fine tuning and maybe replacing some worn horns and it WILL be perfect. Oh yeah my CG on it is at 5.5 or maybe just a tad less.

Its kinda funny how a little bit of a change here and there can make a plane come around.

Thanks for the help,
Dave