Previous in Forum: Near Satellite Collision Last Night   Next in Forum: Sealing Machine
Close
Close
Close
17 comments
Power-User

Join Date: Nov 2009
Posts: 413
Good Answers: 23

Flight Improvement Suggestions Requested for Awesome Giant Hand Launched Glider

10/19/2020 2:17 PM

Register to Reply
Interested in this topic? By joining CR4 you can "subscribe" to
this discussion and receive notification when new comments are added.

Comments rated to be Good Answers:

These comments received enough positive ratings to make them "good answers".
Guru

Join Date: Mar 2007
Location: at the beach in Florida
Posts: 30948
Good Answers: 1727
#1

Re: Flight Improvement Suggestions Requested for Awesome Giant Hand Launched Glider

10/19/2020 3:37 PM

__________________
Break a sweat everyday doing something you enjoy
Register to Reply
Guru

Join Date: Apr 2008
Location: Chicago
Posts: 3989
Good Answers: 144
#2

Re: Flight Improvement Suggestions Requested for Awesome Giant Hand Launched Glider

10/19/2020 3:44 PM

That style of airplane is designed to be slung forward... like with a fixed mount and 20 feet of bungee cord or surgical tube.

Hook, pull, release.

__________________
High Tolerance is Beautiful
Register to Reply
Guru

Join Date: Apr 2010
Location: About 4000 miles from the center of the earth (+/-100 mi)
Posts: 9045
Good Answers: 1031
#3

Re: Flight Improvement Suggestions Requested for Awesome Giant Hand Launched Glider

10/19/2020 10:22 PM

After the launch phase, the remaining distance covered is determined by the lift to drag ratio. By similar triangles, you can prove geometrically that distance/altitude = lift/drag as shown by the diagram below:

To maximize glide distance, minimize drag, make surfaces as smooth as possible. The balance of the aircraft will determine its speed, and at some speed, the lift/drag will be minimum. Adjust weight distribution, this will require trial and error probably.

Register to Reply
Active Contributor

Join Date: Jun 2020
Posts: 14
Good Answers: 1
#4

Re: Flight Improvement Suggestions Requested for Awesome Giant Hand Launched Glider

10/19/2020 10:39 PM

Consider adding some small elevator trim tabs into the aft portion of the wing on each side. Must be identicaly trimmed or will cause turns. No weight penalty as they can be cut into the aft portion of the wing. Pins and thread can set trim angle. Another idea is to launch when there are thermals present. I watched a paper airplane made from an 8.5" X 11" sheet of paper launched from a model rocket as a parasitic glider catch a thermal and was lost from sight and still going over 5 mi away!

Register to Reply
Guru

Join Date: May 2006
Location: Placerville, CA (38° 45N, 120° 47'W)
Posts: 5989
Good Answers: 242
#5
In reply to #4

Re: Flight Improvement Suggestions Requested for Awesome Giant Hand Launched Glider

10/19/2020 11:36 PM

Back in the late '50s, I took a small (≈10" long & wingspan) balsa glider to a fire lookout at the top of the Sierra Buttes, about 50 mi. north of Lake Tahoe. There is a long vertical face on the east side, so on sunny days a significant updraft forms in the early afternoon. I threw the glider out into that updraft, and watched it spiral upward until it reached a layer of air moving rapidly to the East. Using the huge binoculars of the lookout, I was able to (barely) watch it pass over the next ridge, about 12 miles to the East.

__________________
Teaching is a great experience, but there is no better teacher than experience.
Register to Reply
Guru

Join Date: Oct 2006
Location: Surrey BC Canada
Posts: 1571
Good Answers: 40
#6

Re: Flight Improvement Suggestions Requested for Awesome Giant Hand Launched Glider

10/19/2020 11:41 PM

The Clark Y airfoil is a simple airfoil that you can make. There are better shapes, but harder to cut. We used to use cardboard or wood templates and a hot wire to cut the Styrofoam airfoil shape. Covering with paper or aluminum foil will greatly stiffen the wing.

http://airfoiltools.com/plotter/index?airfoil=clarky-il

Smooth surfaces really help.

As previously noted by other posters, weight distribution and elevator tabs allow trimming.

Gliders (sailplane - differentiated by being more efficient and can gain altitude in thermals) generally have long slender wings that provide higher lift to drag.

Register to Reply
Guru

Join Date: Oct 2014
Location: Hemet, Land of milk and honey.
Posts: 2366
Good Answers: 36
#7

Re: Flight Improvement Suggestions Requested for Awesome Giant Hand Launched Glider

10/20/2020 1:01 AM

First, you got to get a giant hand,,,

Register to Reply
Guru

Join Date: Mar 2007
Location: at the beach in Florida
Posts: 30948
Good Answers: 1727
#8
In reply to #7

Re: Flight Improvement Suggestions Requested for Awesome Giant Hand Launched Glider

10/20/2020 7:39 AM

Check...

__________________
Break a sweat everyday doing something you enjoy
Register to Reply
Power-User

Join Date: May 2017
Location: Houston the Emerald City that would be Oz, TX serving art collectors and patrons worldwide
Posts: 216
Good Answers: 8
#9

Re: Flight Improvement Suggestions Requested for Awesome Giant Hand Launched Glider

10/20/2020 10:03 AM

Has this guy ever made paper airplane? The reason I ask is that his plane has a "T" wings to body profile. When you fold a paper airplane you naturally get a "Y" profile. Oh my an airfoil. Also it's easy to fold the wing tips to add Rutan devices.

__________________
To get anywhere fast the first thing you do is go off in the wrong direction.
Register to Reply
2
Guru

Join Date: May 2016
Posts: 1746
Good Answers: 87
#10

Re: Flight Improvement Suggestions Requested for Awesome Giant Hand Launched Glider

10/20/2020 1:47 PM

What I was able to see from the video is that the plane seemed to do a good job of going forward in a straight path, but appeared to have a tendency to nose up a bit and then mush, stall or reverse slip. It also had a tendency to nose down and keep going further down.

A previous comment about adding dihedral might be appropriate, although the deep keel on the plane adds a little bit of effective dihedral by masking the raised wing, combined with a lowered center of gravity due to the deep keel.

It looks like it needs the center of gravity just a bit further forward to cause the nose to drop when speed slows. Some added reflex to the wing trailing edge would tend to push the plane to nose up as speed increases and decrease the nose up when speed decreases.

The foam flitter flies better than I would have guessed it would.

Register to Reply Good Answer (Score 2)
Guru
Engineering Fields - Civil Engineering - Member

Join Date: Mar 2011
Location: ''but, don't we get PAID to ask questions?...''
Posts: 1661
Good Answers: 17
#11

Re: Flight Improvement Suggestions Requested for Awesome Giant Hand Launched Glider

10/21/2020 12:01 PM

You could add a small pair of foam-board, canard-type, winglets to the nose.

If their vertical cross-sections were symmetrical, the over-all center-of-gravity could be moved slightly foreward, without adding more nose-lift...

Start by adding a little too much foam canard weight, and trimming it down by-trial-and-error, to get the balance back toward optimum...

__________________
''illigitimi non carborundum...''(i.e.: don't let the fatherless (self-deluding,sabotaging, long-term-memory-impaired, knee-jerking, cheap-shotting, mono-syllabic, self-annointed, shadow-lurking, back-biting, off-topic-inquisitors) grind you down...)
Register to Reply
Guru

Join Date: Oct 2006
Location: Surrey BC Canada
Posts: 1571
Good Answers: 40
#12
In reply to #11

Re: Flight Improvement Suggestions Requested for Awesome Giant Hand Launched Glider

10/21/2020 2:52 PM

'illigitimi non carborundum...'

illigitimi = bastards

Register to Reply Off Topic (Score 5)
Guru

Join Date: Mar 2007
Location: at the beach in Florida
Posts: 30948
Good Answers: 1727
#13

Re: Flight Improvement Suggestions Requested for Awesome Giant Hand Launched Glider

10/22/2020 1:22 AM

Why not incorporate the design characteristics of the world record holders....

Both the longest distance, above, and longest flight duration, below....

__________________
Break a sweat everyday doing something you enjoy
Register to Reply
2
Guru
Engineering Fields - Civil Engineering - Member

Join Date: Mar 2011
Location: ''but, don't we get PAID to ask questions?...''
Posts: 1661
Good Answers: 17
#14

Re: Flight Improvement Suggestions Requested for Awesome Giant Hand Launched Glider

10/22/2020 1:41 PM

If you just want to move the center-of-gravity a little farther forward, all that is needed is to:

- start from the bottom of the rear of the existing airplane, and measure up the tail a few inches, striking a short mark on the tails' edge;

- draw a straight line from that mark, forward and pararllel, to the top surface;

- carefully cut off the resulting triangular volume of foam-board;

- test-fly the modified airplane, and;

- repeat the process, until sufficiently optimum performance is reached.

__________________
''illigitimi non carborundum...''(i.e.: don't let the fatherless (self-deluding,sabotaging, long-term-memory-impaired, knee-jerking, cheap-shotting, mono-syllabic, self-annointed, shadow-lurking, back-biting, off-topic-inquisitors) grind you down...)
Register to Reply Good Answer (Score 2)
2
Guru

Join Date: Apr 2010
Location: About 4000 miles from the center of the earth (+/-100 mi)
Posts: 9045
Good Answers: 1031
#15

Re: Flight Improvement Suggestions Requested for Awesome Giant Hand Launched Glider

10/25/2020 2:38 PM

Tn airplane has 4 forces acting on it: Thrust, directed forward, drag directed aftward, lift directed upward from the center of lift, and weight directed downward from the center of gravity. A glider, of course, has no engine and thus no thrust. The glider flies slightly nose down so that a component of the lift is directed forward opposite drag.

Example airplane gliding (no engine thrust), lift force tilted forward by the angle of glide.

In the paper airplane, the center of lift is in the plane of the wings. Its location can be found by making a pattern of the wings on a piece of cardboard and then locating center of gravity (balance point) of the cardboard pattern.

The center of gravity is about in the center of the plane and can be found by balancing the plane. The center of gravity will be below the wing area. The weight force acts at the center of gravity and the lift force acts at the center of lift, so the two forces will keep the plane upright. If the center of gravity is slightly forward of the center of lift, the plane will balance slightly nose down, which is desired for stable flight.

The center of gravity below the center of lift will also provide roll stability, but additional roll stability may be added by tilting up the wings (dihedral).

The swept back shape of the wing and the fuselage shape will provide yaw (right-left) stability if the plane is moving forward.

For speed stability, the trailing edge of the wings can be bent up slightly. As the speed of the plane increases, there will be a force that noses it up, slowing the plane down again. This should be combined with moving the center of gravity slightly more forward.

For this design of airplane, the primary factor controlling stable flight is the relationship of the center of lift and center of gravity.

http://isaac.exploratorium.edu/~pauld/activities/flying/PaperAirplaneScience.html

Register to Reply Good Answer (Score 2)
Guru
Engineering Fields - Civil Engineering - Member

Join Date: Mar 2011
Location: ''but, don't we get PAID to ask questions?...''
Posts: 1661
Good Answers: 17
#16
In reply to #15

Re: Flight Improvement Suggestions Requested for Awesome Giant Hand Launched Glider

10/27/2020 12:07 PM

NOW I understand center-of-lift. GA from me.

__________________
''illigitimi non carborundum...''(i.e.: don't let the fatherless (self-deluding,sabotaging, long-term-memory-impaired, knee-jerking, cheap-shotting, mono-syllabic, self-annointed, shadow-lurking, back-biting, off-topic-inquisitors) grind you down...)
Register to Reply
Guru

Join Date: Mar 2007
Location: at the beach in Florida
Posts: 30948
Good Answers: 1727
#17

Re: Flight Improvement Suggestions Requested for Awesome Giant Hand Launched Glider

10/28/2020 10:11 PM

__________________
Break a sweat everyday doing something you enjoy
Register to Reply
Register to Reply 17 comments
Interested in this topic? By joining CR4 you can "subscribe" to
this discussion and receive notification when new comments are added.

Comments rated to be Good Answers:

These comments received enough positive ratings to make them "good answers".
Copy to Clipboard

Users who posted comments:

dkwarner (1); gshaiffer (1); GW (2); JE in Chicago (1); Jpfalt (1); MR. Guest (3); Rixter (2); SolarEagle (4); Stephen Archer (1); tonyhemet (1)

Previous in Forum: Near Satellite Collision Last Night   Next in Forum: Sealing Machine

Advertisement