NighthawkGliders
Enjoy Flight & Enjoy Life
To be honest, I wasn't certain I could build one that could launch a balsa glider with any consistency, but I may have lucked out here and made something that works fairly well. Just sharing my results here.
I just searched around my house and found just the right combination of materials to make one:
Shoe-box, 2 Dowel rods, PVC Pipe, 2 Clothes Pins, 1/4" Balsa Wood, Rubber Bands, Caps from Old Crayola Fat Tip Markers, and some Duct Tape (always handy).
I slopped together something that (gently) chucks my Sandpiper gliders.
(I may have to make video showing how I made this) if anyone is interested.
Details about my Sandpiper Glider:
Wing span: 12"
Wing area: 21 sq in
Weight: 4.5 grams
I was able to get some measurements (to the best of my ability), averaged over a number of flights, and calculated:
Here are the measurements:
Launcher to Wall: 20.5 ft
Launcher Height: 47 in
Air Density: 0.002378 slug/cuft (a number I used, not real measurement that day)
Sink Distance: 27 in
Flight Time: 1.48 s
Here are the calculations:
Air Speed: 9.5 mph (15.29 kph)
Sink Speed: 1.52 ft/s (46.33cm/s)
Lift: 4.47 grams
Drag: 0.49 grams
Glide Angle: 6.26 deg
Glide Ratio (also L/D Ratio): 9.11
Lift Coefficient: 0.292902812
Drag Coefficient: 0.03214787
So, in the end... I think the results turned out decent... but, I wanted to check in with the FT Community...
Given a Balsa Glider of these dimensions, does a 9.11 Glide Ratio seem about right? I was wondering if I should have expected a higher number.
There are a few things I'd like to change about this launcher, especially to make it more customizable. (Things like Launch Speed and Launch Angle come to mind). I had limited space, but I think one of my biggest challenges with this was launching the glider as close to its glide speed and glide angle as possible. In other words, I want it to be settled into its glide right off the gate for more accurate measurements. (My video shows the slow-mo of quite a few launches-- so, they are not perfect by far.)
I'm a noob at this stuff, so your thoughts and comments are welcomed!
I just searched around my house and found just the right combination of materials to make one:
Shoe-box, 2 Dowel rods, PVC Pipe, 2 Clothes Pins, 1/4" Balsa Wood, Rubber Bands, Caps from Old Crayola Fat Tip Markers, and some Duct Tape (always handy).
I slopped together something that (gently) chucks my Sandpiper gliders.
(I may have to make video showing how I made this) if anyone is interested.
Details about my Sandpiper Glider:
Wing span: 12"
Wing area: 21 sq in
Weight: 4.5 grams
I was able to get some measurements (to the best of my ability), averaged over a number of flights, and calculated:
Here are the measurements:
Launcher to Wall: 20.5 ft
Launcher Height: 47 in
Air Density: 0.002378 slug/cuft (a number I used, not real measurement that day)
Sink Distance: 27 in
Flight Time: 1.48 s
Here are the calculations:
Air Speed: 9.5 mph (15.29 kph)
Sink Speed: 1.52 ft/s (46.33cm/s)
Lift: 4.47 grams
Drag: 0.49 grams
Glide Angle: 6.26 deg
Glide Ratio (also L/D Ratio): 9.11
Lift Coefficient: 0.292902812
Drag Coefficient: 0.03214787
So, in the end... I think the results turned out decent... but, I wanted to check in with the FT Community...
Given a Balsa Glider of these dimensions, does a 9.11 Glide Ratio seem about right? I was wondering if I should have expected a higher number.
There are a few things I'd like to change about this launcher, especially to make it more customizable. (Things like Launch Speed and Launch Angle come to mind). I had limited space, but I think one of my biggest challenges with this was launching the glider as close to its glide speed and glide angle as possible. In other words, I want it to be settled into its glide right off the gate for more accurate measurements. (My video shows the slow-mo of quite a few launches-- so, they are not perfect by far.)
I'm a noob at this stuff, so your thoughts and comments are welcomed!