Summit 3 CG?
11-08-2011, 08:22 PM
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RE: Summit 3 CG?
CG location from the plan is 8.125 inches from trailing edge.
For most of the old trike designs, if the tail would not quite stay down when sitting on the wheels, you are close.
plan can be found at: http://aztecair.net/Summit_iii.htm
John
For most of the old trike designs, if the tail would not quite stay down when sitting on the wheels, you are close.
plan can be found at: http://aztecair.net/Summit_iii.htm
John
11-09-2011, 04:42 PM
#4
RE: Summit 3 CG?
ORIGINAL: AllTheGoodNamesAreTaken
Thanks for the link John. Looks like we need some lead in the nose. [
]
Thanks for the link John. Looks like we need some lead in the nose. [
]
Nope, you need a bigger engine. Can you squeeze in a Jett .90?
11-09-2011, 06:25 PM
#8
RE: Summit 3 CG?
ORIGINAL: pitstop000
Hey Jeff, maybe a nose gear would balance it out, Ha ha Lol. [sm=wink_smile.gif]
I think I remember it doesn’t have one, right?
Hey Jeff, maybe a nose gear would balance it out, Ha ha Lol. [sm=wink_smile.gif]
I think I remember it doesn’t have one, right?
The plane was purchased half assembled by my buddy Chis at a swap meet for $100.
11-12-2011, 08:29 AM
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RE: Summit 3 CG?
Holy smokes Jeff!
30 oz - that's almost two pounds of nose weight. How's that even possible. Where is all the radio gear? Sounds like it needs to be laid out anew.
Is the fuel tank on the CG? If so, the batteries can be put behind the FW. A nose gear only weighs a few ounces no matter what kind so something doesn't sound right.
David.
30 oz - that's almost two pounds of nose weight. How's that even possible. Where is all the radio gear? Sounds like it needs to be laid out anew.
Is the fuel tank on the CG? If so, the batteries can be put behind the FW. A nose gear only weighs a few ounces no matter what kind so something doesn't sound right.
David.
11-12-2011, 10:15 AM
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RE: Summit 3 CG?
Did you do the finishing and painting?
If not, the stab was probably sheeted with pine and finished with two ounce cloth. If you have an adjustable stab as the plans call for, the stab weight is easy to check. I assume the stab is not monokoted but painted? Try and check the rudder construction for overkill as well. I assume you did not move any servos to the tail? As I recall, the Summit was supposed to build up very light.
Another possibility is that this is not an original kit epoxyglass fuselage but a knockoff with a heavy layup or a wood fuselage built with more pine. Without the nose weight I would still consider 9 and a quarter pounds to be a bit heavy for this plane.
We did fly with eleven pound airplanes back in the day due to bad materials, too much paint, repairs etc and it will fly OK but not the way it did in Ivan's hands at about 8 pounds. I'm referring to the capabilities of the plane only- not many pilot's with Ivan's skills.
John
If not, the stab was probably sheeted with pine and finished with two ounce cloth. If you have an adjustable stab as the plans call for, the stab weight is easy to check. I assume the stab is not monokoted but painted? Try and check the rudder construction for overkill as well. I assume you did not move any servos to the tail? As I recall, the Summit was supposed to build up very light.
Another possibility is that this is not an original kit epoxyglass fuselage but a knockoff with a heavy layup or a wood fuselage built with more pine. Without the nose weight I would still consider 9 and a quarter pounds to be a bit heavy for this plane.
We did fly with eleven pound airplanes back in the day due to bad materials, too much paint, repairs etc and it will fly OK but not the way it did in Ivan's hands at about 8 pounds. I'm referring to the capabilities of the plane only- not many pilot's with Ivan's skills.
John
11-14-2011, 09:12 AM
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RE: Summit 3 CG?
Chuck,
all excellent advice but Jeff is talking about 30 oz in the nose not ~3 oz; one tenth of that. In other words, once balanced the model still needs two pounds somewhere near the FW. That's why it weighs 11 lbs. Otherwise it would weigh the more adequate 9 lbs.
I'd imagine the fuel tank might sit between the CG and the wing LE with the tail servos right behind the tank. Throttle servo and batteries would go in front of the fuel tank. The thing is that nose gear or not, that would account for only 8 oz max and the mains are in front of the CG already.
A bit puzzling.
David.
all excellent advice but Jeff is talking about 30 oz in the nose not ~3 oz; one tenth of that. In other words, once balanced the model still needs two pounds somewhere near the FW. That's why it weighs 11 lbs. Otherwise it would weigh the more adequate 9 lbs.
I'd imagine the fuel tank might sit between the CG and the wing LE with the tail servos right behind the tank. Throttle servo and batteries would go in front of the fuel tank. The thing is that nose gear or not, that would account for only 8 oz max and the mains are in front of the CG already.
A bit puzzling.
David.
11-16-2011, 06:05 AM
#14
RE: Summit 3 CG?
I haven't snapped any photos of the installation of the gear, but here's a description:
The airframe is a glass fuse, balsa covered wings and tail, glassed and painted with epoxy (very light coat - as I did that myself). The plane was purchased with the stabilizer glued in place. It looks to have been a one piece stab and slid through the fuse and glued in place. The airframe was/ is set up as a tail dragger with mechanicals. The retract servo is in the fuse (retracts and servo are in front of the CG). The rudder and elevator servos are just aft of the wing tube. The elevator is actuated by a dave brown fiberglass pushrod with a 2/56 music wire wye. The rudder is pull/pull. The throttle servo (HS-81) is just in front of the retract servo. The tank sits on a platform just in front of the CG - over the retract servo. The battery (5200mAh LiIon) sits on a platform right behind the firewall.
The engine is a YS .61AR with a Macs quiet pipe and full length header. Prop is an APC 12/11 surrounded by an aluminum spinner.
Just for fun I removed EVERYTHING aft of the CG. - servos, pushrods, control horns, tail wheel, etc. Still balanced 1" behind the CG.
The plane has a very long moment. The center of the empannage is 36" behind the CG. The firewall sits 12" in front of the CG. It takes a LARGE amout of weight to move the CG forward just the slightest bit. If I remember correctly, 6oz behind the firewall moved the CG forward 1/4".
At this point, short of rebuilding the entire empannage out of carbon fiber and helium, we are just going to add the weight to balance it and see how it flies.
The airframe is a glass fuse, balsa covered wings and tail, glassed and painted with epoxy (very light coat - as I did that myself). The plane was purchased with the stabilizer glued in place. It looks to have been a one piece stab and slid through the fuse and glued in place. The airframe was/ is set up as a tail dragger with mechanicals. The retract servo is in the fuse (retracts and servo are in front of the CG). The rudder and elevator servos are just aft of the wing tube. The elevator is actuated by a dave brown fiberglass pushrod with a 2/56 music wire wye. The rudder is pull/pull. The throttle servo (HS-81) is just in front of the retract servo. The tank sits on a platform just in front of the CG - over the retract servo. The battery (5200mAh LiIon) sits on a platform right behind the firewall.
The engine is a YS .61AR with a Macs quiet pipe and full length header. Prop is an APC 12/11 surrounded by an aluminum spinner.
Just for fun I removed EVERYTHING aft of the CG. - servos, pushrods, control horns, tail wheel, etc. Still balanced 1" behind the CG.
The plane has a very long moment. The center of the empannage is 36" behind the CG. The firewall sits 12" in front of the CG. It takes a LARGE amout of weight to move the CG forward just the slightest bit. If I remember correctly, 6oz behind the firewall moved the CG forward 1/4".
At this point, short of rebuilding the entire empannage out of carbon fiber and helium, we are just going to add the weight to balance it and see how it flies.
