ORIGINAL: Jet_Plane
ORIGINAL: rmh
4.5 degrees offset?
That is a BUNCH!
that's abit offensive if you don't mind me saying. Maybe your indoor foamies dont need that much right thrust but dont assume what works for them is a universal truth for all models.
The model is a
Precision Aerobatics Ultimate AMR. It comes stock with 3Deg right thrust but when doing the standard vertical up-line test i consistently had the model yawing away left soI added an extra shim that took the right thrust to about 4.5deg (give ar take half a degree). She now goes vertical without any use of rudder. Increased right thrust also sorted out other areas such as a slight sideways drift through consecutive loops, now eliminated. CG is spot of by the way.
As for the model being underpowered or overweight nothing could be further from the truth. This is a 40" span 3D aerobatic biplane weighing under 40oz with a wing loading of 9.5oz/sq ft. It's got about 200W per lb power loading and a thrust:weight ratio of 2:1.. overweight and underpowered it isn't... However it does swing a 14" prop which is pretty huge for a 40" span model so that probably explains the need for more right thrust than usual. It doesn't have any down thrust.
As you might still think I'm talking 'a BUNCH' then here's a photo, put a protractor on it if you wish.
I'm pretty sure Rich did not mean to offend. 4.5 degrees is a little more then what we usually see but it does go to prove a point of mine. I tell people all the time to listen and watch your airplane, she will tell you what she needs. Often I am asked where my needle settings are, where my CG is. How many PRMs do I get. My answer is usually " Beats me". Not 100% true statement as when I get these adjusted to where I like them I do omake a note for future reference. Lets take CG for example. I usually set it for a safe maiden then fly the airplane. Do a couple of tests and then adjust by moving batteries around or switching some components until I fet the flight performance I want. Pulling to a 45, doing a 1/2 roll to invert and letting off the sticks. Over the next 6 to 7 seconds I want the airplane to arc to level invert. For your high power, draggy bibe, I would expect it to require more right thrust as you have that big prop under more load then with a cleaner mono. You listened to the airplane and gave her what she wanted...........Bravo!