Trim Problem

[Garf]

I seem to be a little weak on the ability to properly trim a model to eliminate certain types of problems. I have a couple of models that display a wobble on the lower right corner of the square 8 and the third corner of the triangle. What should I look for with this problem?

[Mark Scarborough]

You say wiggle, is it dropping  a wing tip? is it yaw? what is the plane doing.

[Garf]

Its like the outboard wing flaps. It only does this on inside maneuvers, and at higher speeds like the last corner of the triangle.

[Howard Rush]

By that, I presume you mean it's rolling-- birds flap their wings mostly about the x axis.  Those are the corners that require the most lift.  Take out some tip weight. 

I assume that if you have flaps, you have taped the hingeline.  If not, there is no point in trying any other remedies.   

[Ralph Wenzel (d)]

If the plane is "flapping" only in the bottom right corners (and I presume this includes the last corner of the Hourglass, even though it's not mentioned . . .),  I wonder if the problem is only too much wingtip weight. It's possible there may be some flap (or even elevator) misalignment, too, which favors the outside maneuvers. One additional possibility might be to slow the plane a bit with a very slightly lower-pitch prop. Just a thought . . .

[Mark Scarborough]

Tip weight sounds like a good place to start.
if you balance the plane on the rudder and prop hub, how much does the outboard tip weigh? for a 40 sized ship, somewhere around an ounce heavier ( very rough starting point) should be a start, then watch for the tip to drop on outside square corners if its to much

[John Stiles]

Maybe it's a vortex

[John Stiles]

Hi John. By vortex I assumed you were being on the silly side. But on reflection and a dab of guilt I realized you meant the vortex off the wing or turbulence. Sorry for the silly A$$ answer. Every time I hear about the term Vortex I think of the sillyness down in the Taos, NM area.  Not Arizona. Nothing silly there.

Well, I got a pretty good laugh out of it ....yes, that's what I meant Actually, I had a similar problem once, but my linkage was weak. I tend to build with what I have on the farm, and sometimes, I get undesirable results.

[Jim Pollock]

My old Smoothie I had back in High School did that and I assumed that it was stalling since the plane weighed about 48 ounces, and the super power plant (McCoy .35 Ugh) was turning that Top Flite Nylon prop for all it was worth!
And yes it was boiled!  Boy, those were the days!

Jim Pollock  

[Steve Helmick]

Or could it be stalling...wallowing through the corner? Any model will do that, if it's a) noseheavy or b) has too much elevator for wing lift available. Seal the flaps and elevator hingelines!

I pretty much fixed my Twister-ish by also reducing elevator travel (moved the pushrod one hole down on the elev. horn). It changed the way the plane flies a lot...much better corners, but very different in control response. I had to narrow the handle spacing 1/2", and then widened it out gradually...now back to original spacing plus some. The plane has gotten better and better. It's a learning experience. I like that!  Steve

[Garf]

The models doing this are the smaller ones like the Trixter Barnstormer and the Bassmaster (ringmaster S1 wing and basswood fuselage, moments from Midwest ME-109.). My bigger ones don't have this problem.