Bert Hogue
New Member
What is the cg on the 30" edge 540 profile?
General 30" Edge 540 profile cg?
- Thread starter Bert Hogue
- Start date
RandyDSok
Well-Known Member
By "profile", I assume you mean a flat construction... and not one with a typical airfoil and full body. Not that it matters, since aerodynamics will still require the same math to get the answer you want.
I'm going to assume some more... I assume you are designing this from scratch and have no instructions or a manual to look at. I assume that since the CG should be included in those.
Note that engineering an aircraft requires a bit of experience and a bit of math to get it at least close. If you are not an experienced pilot this may not be the way to start in the hobby of rc aircraft, buy a prebuilt or predesigned one first. If, on the other hand, you are experienced with RC aircraft already and are wanting to expand into also designing... that's another story.
Please note that a 30" aircraft will be very twitchy flying when compared to a much larger wingspan. They also will not be tolerant of any wind to speak of.
Since I've not designed an Edge... I can only pass on what I've read. From that... typically the CG on an Edge is at the 30% point of the MAC of the wing. The MAC is the mean aerodynamic chord. It is calculated using a formula where you have the dimensions of width of the wing root, the wing tip and the length of the wing. Then you plug those figures into the formula.
Here is a webpage fully describing how to calculate the MAC Airfield Models - How to Find or Calculate the Mean Aerodynamic Chord (MAC) of a Wing
On a properly designed, typical 3D and not flat airframe Edge airframe... often the wings will attach using a tube. The typical CG's on these are from the front of the tube to the rear of the tube. Notice my use of the word "typically", that is because not all of them are engineered the same way for various reasons.
I'm going to assume some more... I assume you are designing this from scratch and have no instructions or a manual to look at. I assume that since the CG should be included in those.
Note that engineering an aircraft requires a bit of experience and a bit of math to get it at least close. If you are not an experienced pilot this may not be the way to start in the hobby of rc aircraft, buy a prebuilt or predesigned one first. If, on the other hand, you are experienced with RC aircraft already and are wanting to expand into also designing... that's another story.
Please note that a 30" aircraft will be very twitchy flying when compared to a much larger wingspan. They also will not be tolerant of any wind to speak of.
Since I've not designed an Edge... I can only pass on what I've read. From that... typically the CG on an Edge is at the 30% point of the MAC of the wing. The MAC is the mean aerodynamic chord. It is calculated using a formula where you have the dimensions of width of the wing root, the wing tip and the length of the wing. Then you plug those figures into the formula.
Here is a webpage fully describing how to calculate the MAC Airfield Models - How to Find or Calculate the Mean Aerodynamic Chord (MAC) of a Wing
On a properly designed, typical 3D and not flat airframe Edge airframe... often the wings will attach using a tube. The typical CG's on these are from the front of the tube to the rear of the tube. Notice my use of the word "typically", that is because not all of them are engineered the same way for various reasons.