surfimp
Dec 07, 2003, 06:53 PM
For a while now I've been kicking around the idea of building a relatively lightweight Coroplast sloper that can be flown in something less than a gale force wind. The problem with most Coro sloper designs (i.e. Mugi, Dazi, etc.) besides not having "real" airfoils is that they are quite heavy for their size as compared to an EPP or balsa plane, and consequently require pretty strong wind to fly (i.e 15mph or more at a decent slope). However Coro is cheap and planes are quite easy to build from it, and they're fun experiments.
So, towards that end I've been thinking about trying out a single surface/Jedelsky sort of wing on a tailless plank. The wing itself would be made from 2mm Coro and probably be around 36" to 48" in span. There would be a central fuselage pod folded from 2mm Coro that would serve to hold the radio gear and provide the central rib shape to the wing (it would be hotglued to the bottom of the wing). Would also serve to mount the single center fin. I'd put two more battens hotglued to the underside of the wing at the wingtips, and possibly a third batten in the middle of each half span (probably only if I built it 48"). The elevons would be controlled by two servos set in the top of the wing that would run pushrods out at about a 45* angle to the elevons (very draggy but easy to build).
My question is, am I smoking something? I know that single surface airfoils work OK for low speed applications, so it might really not be too hot for a slope glider, as penetration is pretty important. Also, I know it's asking a lot to try to make a single surface airfoil also perform for a tailless design, and then compounded with the whole Coroplast / SPAD deisgn philosophy maybe I'm just suffering delusions? Obviously the only way to test this is to build the thing, but any advice from the wiser and more experienced luminaries would of course be welcome.
So, towards that end I've been thinking about trying out a single surface/Jedelsky sort of wing on a tailless plank. The wing itself would be made from 2mm Coro and probably be around 36" to 48" in span. There would be a central fuselage pod folded from 2mm Coro that would serve to hold the radio gear and provide the central rib shape to the wing (it would be hotglued to the bottom of the wing). Would also serve to mount the single center fin. I'd put two more battens hotglued to the underside of the wing at the wingtips, and possibly a third batten in the middle of each half span (probably only if I built it 48"). The elevons would be controlled by two servos set in the top of the wing that would run pushrods out at about a 45* angle to the elevons (very draggy but easy to build).
My question is, am I smoking something? I know that single surface airfoils work OK for low speed applications, so it might really not be too hot for a slope glider, as penetration is pretty important. Also, I know it's asking a lot to try to make a single surface airfoil also perform for a tailless design, and then compounded with the whole Coroplast / SPAD deisgn philosophy maybe I'm just suffering delusions? Obviously the only way to test this is to build the thing, but any advice from the wiser and more experienced luminaries would of course be welcome.