XA (3D) with Foam Board Design Challenge
Boberticus
Active member
Is XD any different from 4D?
no reversable prop on XD?
no reversable prop on XD?
XA isn't 4D, it's just higher energy 3D flying so more fast stuff instead of rolling harriers and that kind of thing.
Jonny Gum
Elite member
XA is like fast paced and aggressive 3D. Lots of directional changes, snap rolls, high stress maneuvers. Traditional 3D is kind of just harriers and hovering. Basically the idea is to make the Lamborghini of airplanes. Very high performance.
Good way to put it.
OliverW
Legendary member
(cough cough gamebird cough cough)
Jonny Gum
Elite member
... maybe
That’s a great idea - I like it!
varg
Build cheap, crash cheap
I doubt the overweight nature of anyone's FT Edge build would make it worse at this kind of flying provided it still has a sufficient thrust to weight ratio. Unfortunately, FliteTest doesn't publish very good specs for the planes; lacking wing area for example, and I don't have an edge to measure. However, the balsa and foam planes alike that fly this way have a much higher wing loading and Wing Cube Loading than any FT Edge is likely to have. The higher wing loading is actually necessary for a lot of the more "high energy" maneuvers. You'll find, for example If anything most foamboard planes will be too light and not stiff enough for "XA" vs slow 3D. You'll want to aim for a WCL of around 10 for this, not <5. You won't get the energetic nature of the inertia heavy maneuvers like poptops with a lightly loaded plane.
Joe Carpino
Well-known member
I got the plans for the final version of my design for this challenge. A super simple 3D acro stick. Somehow I started on fully formed, then went to box and turtle deck, and now at full 3x3😂
Joe Carpino
Well-known member
Joe Carpino
Well-known member
Does anyone know of a heavy thing I can stuff in the fuselage?😂😂
Grifflyer
WWII fanatic
Batteries.
Joe Carpino
Well-known member
I have a 2200 3s I’m gonna put in it
varg
Build cheap, crash cheap
Well the commercially available 3D planes don't have a park flyer's WCL because they're fairly solid, significantly powerful and loaded with reinforcements. So put reinforcements in it, just adding weight will probably just result in something ripping off when you do a few too many blenders, crankshafts or knife edge spins.
I fall back on it because it is the most direct comparison possible between a 3D capable FT plane and a 3D capable foam plane* but for example a bushwacker weighs ~720g with a battery, a Timber X weighs ~1600g. They are similar, practically the same size, I have both of them, and they fly completely differently. The bushwacker is mostly free air by volume, runs 3S, has half the ESC capacity, etc. It'll hover, flat spin, harrier, etc, but can't really do any high energy maneuvers.
*I don't know of any non profile versions of the usual suspects; Edge, Extra, CAP, Laser, etc which are ~1m like the FT Edge for direct comparison, that's why I went straight to wing cube loading
I fall back on it because it is the most direct comparison possible between a 3D capable FT plane and a 3D capable foam plane* but for example a bushwacker weighs ~720g with a battery, a Timber X weighs ~1600g. They are similar, practically the same size, I have both of them, and they fly completely differently. The bushwacker is mostly free air by volume, runs 3S, has half the ESC capacity, etc. It'll hover, flat spin, harrier, etc, but can't really do any high energy maneuvers.
*I don't know of any non profile versions of the usual suspects; Edge, Extra, CAP, Laser, etc which are ~1m like the FT Edge for direct comparison, that's why I went straight to wing cube loading
Jonny Gum
Elite member
So if I'm understanding this right, the lighter nature and low wing loading of something like a profile micro 3d plane allows it to do traditional low and slow 3d, but not high energy. An xa plane inherently needs a bit more weight so that it can carry momentum through high energy manuevers, but i would assume that there is a sweetspot. If the plane weighs too much, then you lose slower manuevers such as harriers.
So far, the biggest problem I have realized with my own 3d designs is that they are very squirrely, which I had previosly thought was due to a high wing loading, however I am not too sure anymore. I'm going to do a fair bit of research and see what I come up with.
So far, the biggest problem I have realized with my own 3d designs is that they are very squirrely, which I had previosly thought was due to a high wing loading, however I am not too sure anymore. I'm going to do a fair bit of research and see what I come up with.
Jonny Gum
Elite member
I found this on a flyrc article
Lower wing-loading (WL): WL represents a ratio of a plane’s AUW to its total wing area. Small, foam, profile 3D planes can have a WL as low as five ounces per square foot, while for larger wood 3D planes that number can approach (and exceed) the high teens. Planes with high WL can be thrown into aggressive tumbling maneuvers, but when it comes to post-stall, that higher WL often contributes to instability and wing-rock. The lower a plane’s WL the more “floaty” it will feel, resulting in higher degrees of confidence when it comes to bringing your plane in for some low and slow fun. It’s been argued that wing cube-loading (WCL) is a more accurate determination of a plane’s flight characteristics, but that’s a mathematically complicated conversation for another day.
This confirms my initial idea that the high wing loading causes unstable post stall flight and such.
Lower wing-loading (WL): WL represents a ratio of a plane’s AUW to its total wing area. Small, foam, profile 3D planes can have a WL as low as five ounces per square foot, while for larger wood 3D planes that number can approach (and exceed) the high teens. Planes with high WL can be thrown into aggressive tumbling maneuvers, but when it comes to post-stall, that higher WL often contributes to instability and wing-rock. The lower a plane’s WL the more “floaty” it will feel, resulting in higher degrees of confidence when it comes to bringing your plane in for some low and slow fun. It’s been argued that wing cube-loading (WCL) is a more accurate determination of a plane’s flight characteristics, but that’s a mathematically complicated conversation for another day.
This confirms my initial idea that the high wing loading causes unstable post stall flight and such.
Jonny Gum
Elite member
I did some digging and found that a typical XA plane has a WCL of roughly 7 to 9, seven being more floaty.
Here are some numbers I worked out-
EF Slick EXP 52” - WCL= 7.8
EF Extra EXP v2 48” - WCL= 7
EF Extra v2 104” - WCL= 9.3
EF Edge 540-T EXP v2 60” - WCL= 7.6
I'm going to aim for about 7.5, as my design will be closest in size to the 48" Extra and the 52" Slick, which has a WCL of 7 and 7.8 respectively.
Here are some numbers I worked out-
EF Slick EXP 52” - WCL= 7.8
EF Extra EXP v2 48” - WCL= 7
EF Extra v2 104” - WCL= 9.3
EF Edge 540-T EXP v2 60” - WCL= 7.6
I'm going to aim for about 7.5, as my design will be closest in size to the 48" Extra and the 52" Slick, which has a WCL of 7 and 7.8 respectively.
FlyingWithRyan
Elite member
Honestly the biggest problems with the FT edge for XA is how draggy it is and how little power it has on a C pack radial. Definitely needs a larger motor in the 3000 size range instead of the 2150 that I think the radial is
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