I am no aerodynamical weeezardo (THAT'S FER SURE!
)....but the quest in building any plane that I build, is to keep it not only light in weight....but more importantly, keeping the frame and control system from flexing, which will keep that model performaning better for a longer period of time before the ravages of fatique begin to take its tole.
Try to remember, that when control surfaces bend or flex this will effect not only the flight path...but also require the pilot to make constant corrections at the handle.
Any stunt modeler who has ever built the older stock Nobler with that holyer' than thou' fuselage...or didn't take care to beef up the stab and elevators with the right selection of quality balsa....knows the feeling and what happens when flying that model in high wind conditions.
The Nobler wasn't the first or the last model to experience not only flexing of the airframe (due to design flaws...but equally AND MOST IMPORTANT IS FLEXING OF THE CONTROL SYSTEM ITSELF can reduce the flying quality and consistency of performance.
So often many modelers beef up the airframe..but IGNOR bushing or beefing the pushrod, bellcrank etc and choosing the right stiffness for flaps, elevators..etc.
Actually to me, the control horns themselves are the last buggaaaboo in the control line stunt model flexsation-demon thangie' that bug me the most.
It just takes ONE ITEM IN THAT FLEX FOOD CHAIN control system ...to make a "sow out of silk wallet!"
Years ago...I had a beautiful old Kenhi Panther that flew awesome in light air...but in the wind it hunted...opened up on the square corners with a bottom back-corner hourglass from HELL!
After cutting into the body....I added some plywood bushing-stops to just one main fuselage former and that inproved the flight performance.DAY AND NIGHT difference.
Like the duel line precision event sport kites that I fly, the frame stiffness is very important for proper tracking but equally important is the FRAME BALANCE CG POINTS THEMSELVES.
Frame flex during the power faze is important but also the balance point is equally important. If a frame (be it those kites...or a stunt model) when under flying "G" loads...the weirdest things can happen and effect the flight path. The kites however fly from specta bridles...and even a soft bridle line can effect the most perfectly constructed frame.
Being a human bein'...we tend to teach our pea brains to train our muscle memory... then we go about trying to understand our models strange and individual habitual flight chacteristics,
INSTEAD OF TRYING TO FIND OUT WHAT IN THE FIRST PLACE IS CAUSING these flight path changes that take place under different flying or weather wind conditions.
Amazing how many flyers just give up and simply LIVE WITH THAT LACK LUSTER MODEL and in the end, they just LEARN TO EITHER LOVE OR LEAVE UM.
Kinda sad that we just give up on that model with the poor trim problem and then in some cases find it easier just to build another model...and go through that same process over and over again as we continue the fleeting search for the HOLY GRAIL OF STUNT MODELS.
bottom line divil...
My feeling is...that a twin or triple boomed stunt model has SOOOO MUCH GOING FOR IT!
I finally found one slide that I took of Jim's & Jack's 68 nats Torino....just before that beautiful 1st qualification flight of the day.