Diamond Dust Kit
06-04-2013, 07:57 PM
#26
RE: Diamond Dust Kit
Yes, a big Sidewinder would be very cool.
It would be a total crapshoot to commit to such a fat wing...the wing needs to be at least as thick as the engine is wide at the root.
You can get 1/16" or 3/32" balsa to lay down in a compound curve, so the wing could taper in thickness like the modern military designs do. The spars would need to be "arched" against a stout web, to eliminate airfoil thickness as soon as possible moving away from the center section. The web doesn't need to be continuous [full span]...just where the spars need to be pursuaded to merge together after "leaving" the center section of the wing. The whole wing would be designed after the spar design actually got built and evaluated.
At the worst it would end up becoming a cool looking conversation piece no matter how fast it goes.
It would be a total crapshoot to commit to such a fat wing...the wing needs to be at least as thick as the engine is wide at the root.
You can get 1/16" or 3/32" balsa to lay down in a compound curve, so the wing could taper in thickness like the modern military designs do. The spars would need to be "arched" against a stout web, to eliminate airfoil thickness as soon as possible moving away from the center section. The web doesn't need to be continuous [full span]...just where the spars need to be pursuaded to merge together after "leaving" the center section of the wing. The whole wing would be designed after the spar design actually got built and evaluated.
At the worst it would end up becoming a cool looking conversation piece no matter how fast it goes.
06-04-2013, 08:50 PM
#27
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RE: Diamond Dust Kit
Something along the lines of this shot of the Boeing X 45 with a bit less sweep.
The spar would have to align with the interior bulkhead/former type of thing I used in my Stingray, interesting idea. I saw a photo of the structure of one of these drones and it seemed to be along the lines that you have mentioned.
As a guess I would think the root section would wind up having to be about three inches thick, roughly six inches wide to accommodate the engine, pipe, fuel tank and radio gear.
The spar would have to align with the interior bulkhead/former type of thing I used in my Stingray, interesting idea. I saw a photo of the structure of one of these drones and it seemed to be along the lines that you have mentioned.
As a guess I would think the root section would wind up having to be about three inches thick, roughly six inches wide to accommodate the engine, pipe, fuel tank and radio gear.
06-05-2013, 10:13 AM
#28
RE: Diamond Dust Kit
Yep, I think you've got a good idea there for what it would look like.
Take a look at the AMA rules for Q40 design and construction and check out the minimum cross sectional area requirements for the fuselage and then consider how fast those planes are. I was surprised when I first saw those minimum dimensions.
No matter how you slice it, the object of the Sidewinder project would be to minimize frontal area and to eliminate the drag that is typical between a conventional fuselage and wing. The exit of the pipe at the rear of the plane would be assymetric drag...but it would be partially blanked out by the thick airfoil ahead of it.
I'm surprised that there aren't more examples of this layout in the RC World. It's pretty common in Control line Speed and racing.
Take a look at the AMA rules for Q40 design and construction and check out the minimum cross sectional area requirements for the fuselage and then consider how fast those planes are. I was surprised when I first saw those minimum dimensions.
No matter how you slice it, the object of the Sidewinder project would be to minimize frontal area and to eliminate the drag that is typical between a conventional fuselage and wing. The exit of the pipe at the rear of the plane would be assymetric drag...but it would be partially blanked out by the thick airfoil ahead of it.
I'm surprised that there aren't more examples of this layout in the RC World. It's pretty common in Control line Speed and racing.
