PHOENIX FROM HANGER 9
06-19-2011, 10:39 AM
#2
Join Date: Oct 2002
Location: Chilliwack, BC, CANADA
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RE: PHOENIX FROM HANGER 9
Most of us fly our models with the CG well behind the 25% point. If 25% is at 4 inches that implies that the root chord is 16 inches wide. And with the swept back and tapered wing that means that 7 inches is still quite conservative.
You'll end up fine tuning the CG once you're flying anyway. You'll do things like see how it performs in vertical lines both up and down and set the CG and associated elevator trim to achieve neutral handling and neutral pitch stability such that the model goes where you point it and doesn't self correct at all.
You'll end up fine tuning the CG once you're flying anyway. You'll do things like see how it performs in vertical lines both up and down and set the CG and associated elevator trim to achieve neutral handling and neutral pitch stability such that the model goes where you point it and doesn't self correct at all.
06-20-2011, 06:44 AM
#5
RE: PHOENIX FROM HANGER 9
Here you go:
According to your measurements
25% of MAC should be around 7" back from the LE measured at the root.
33.3% of MAC should be around 8" back from the LE measured at the root.
As Matthews pointed out, the manual seems to be conservative and gives you room to experiment by moving the CG aft in little increments.
Nice bird!
According to your measurements
25% of MAC should be around 7" back from the LE measured at the root.
33.3% of MAC should be around 8" back from the LE measured at the root.
As Matthews pointed out, the manual seems to be conservative and gives you room to experiment by moving the CG aft in little increments.
Nice bird!
06-20-2011, 05:28 PM
#8
RE: PHOENIX FROM HANGER 9
You are welcome, neighbor.
I have found this article about your plane:
http://www.rcuniverse.com/magazine/a...rticle_id=1332
I have found this article about your plane:
http://www.rcuniverse.com/magazine/a...rticle_id=1332
06-23-2011, 04:29 AM
#10
RE: PHOENIX FROM HANGER 9
HI.. You are a design wizard i see.. Do you have an airfiol ,that you feel, has a good ,gental stall?? Also,not to much neg. pitch when flaps deployed? Will be used on a jet. Leading edge sweep around ,,35 deg.. speed is not needed. Sport plane..
06-23-2011, 10:03 AM
#11
Join Date: Oct 2002
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RE: PHOENIX FROM HANGER 9
Assuming that was me you were asking?
So this will be a sport model that sort of looks like a jet?
The desire for how the airfoil stalls is based on how you want to fly the model. If it's a sport model I'm assuming that you'll want to do some snap rolls and other maneuvers that require a sudden failure of the lift from the wing. For this purpose a truly gentle stall isn't really what you want. It would make it that much harder to do the snapping maneuvers. This is why a lot of the hot aerobatic ships these days like Extras and Sukois and such have their owners complaining about how hard it is to land the models. The priority on those designs was to make them so they can snap or stall easily and deeply to enhance the 3D maneuvers. But that has the effect of making the landings very hairy and requireing superior skill and judgement to avoid having the wing stall and drop off.
So before anyone can suggest an airfoil you'll need to supply a lot more information. And frankly it would likely be better off coming in the form of a new thread so it doesn't derail this one which seems to be pretty much finished. Be sure to include information about the shape of the wing and of the fuselage. Or better yet a sketch or other drawing of the top view.
So this will be a sport model that sort of looks like a jet?
The desire for how the airfoil stalls is based on how you want to fly the model. If it's a sport model I'm assuming that you'll want to do some snap rolls and other maneuvers that require a sudden failure of the lift from the wing. For this purpose a truly gentle stall isn't really what you want. It would make it that much harder to do the snapping maneuvers. This is why a lot of the hot aerobatic ships these days like Extras and Sukois and such have their owners complaining about how hard it is to land the models. The priority on those designs was to make them so they can snap or stall easily and deeply to enhance the 3D maneuvers. But that has the effect of making the landings very hairy and requireing superior skill and judgement to avoid having the wing stall and drop off.
So before anyone can suggest an airfoil you'll need to supply a lot more information. And frankly it would likely be better off coming in the form of a new thread so it doesn't derail this one which seems to be pretty much finished. Be sure to include information about the shape of the wing and of the fuselage. Or better yet a sketch or other drawing of the top view.
