I have a dilemma with a combat ship.  It won't do outside manuvers.  Inside are fine.  2 figure 8's last night almost resulted in ground strikes (I'm talking hand over my head, standing on tip toes and full down) and then I went high and tried an outside loop and it practically dove straight in.  It never tucked from vertical.  Balance is on the leading edge and slightly nose heavy (no fuel).  25 or so degrees elevator up and down.  Black widow on 36 foot .008 lines.  Only damage to the plane was a cracked elevator.  Had the same problem with a Little Satan but it didn't fair as well.

Thanks,

John   

Things that can cause your problem, in addition to Mr. Rice's pushrod suggestion, are thrustline misadjustments and bellcrank not being straight fore and aft when the elevator is in neutral.  Handle adjustment should be dead vertical when the elevator is in neutral, too.

Thanks Guys.  Now keep in mind I don't know squat, but if I reduce the up travel, my inside loops would be larger.  They currently are not too tight nor does it stall.  If the pushrod were flexing, it could only do it on inside manuvers since down control is pulling the rod.  Up control would be pushing so if it were flexing, my inside manuvers would suffer.  And as for the bellcrank, does it matter (read first sentence again) if it isn't exactly parallel @ neutral if I get 25 or so degrees at full deflection both ways?  I too was thinking along the CG figuring if it was in a dive and I was trying to pull out it may not tuck in either direction (inside or outside).  All of the dive recoveries were outside so if I had've done an inside pull up from a dive it may have done the same thing.  I will try the balance thing first and report back.  Everyone please understand I'm not trying to be confrontational, just typing out my thoughts (which could be wrong refer to first sentence again).  Thanks again,

John

Ooooo, I thought you were going to send me plane tickets so I could bring it to you.     Guess that was a missunderstanding.  Only has about 3 bucks worth of wood, would be cheaper to just ship it to you and let you fly it and tell me what is wrong, but that wouldn't be nearly as fun.  Let's see how the cg thing works.

John

...And as for the bellcrank, does it matter (read first sentence again) if it isn't exactly parallel @ neutral if I get 25 or so degrees at full deflection both ways?  

John,
If you observe the bellcrank you will find that it provides more linear movement near center than on the extremes, so yes, it does matter that the elevator is centered with bellcrank movement.

Since you are getting enough elevator movement, chances are that the thrust line is a little out of adjustment. You might try adding some washers under the upper mounting lugs, or better yet, a tapered wooden shim. Checking the thrust line should be easy with just a visual check.

Sooo, you have a few things to check. Good luck.

George

Combat and other flying wings are really sensitive to adjustments.  I am still tweaking my Sky Streak, usually 1/2 turn on the elevator clevis and matching handle adjustment at a time.  It ALMOST turns insides and outsides equally, but not quite.  I'll get there!  (it will do a competitive pattern, as noted on another thread, but perfection is the goal)