Elastic Launched Glider B

[Bilbo McSwaggins]

This may sound stupid, but I am building a 80 cm. launcher and can't find any printable rulers that I like. (they are all too small or hard to read)

[bernard]

This may sound stupid, but I am building a 80 cm. launcher and can't find any printable rulers that I like. :oops: (they are all too small or hard to read)

Could you cut a meter stick or yard stick and use that in your launcher?

[fifty_missions]

This may sound stupid, but I am building a 80 cm. launcher and can't find any printable rulers that I like. (they are all too small or hard to read)

What will be the height of the flying site? if this is to be a hand-held launcher, I would recommend using a meter stick cut to the 80 cm (why that particular length?) but would recommend attaching a strong handle. I have witnessed some launch failures due to teams struggling with trying to hold the bare meter stick.

Use that cut-off section of the meter stick for the handle's parts. Start with the inside portion of a laminated handle structure as it already matches the meter stick's thickness. Cut the end at a slight angle similar to a pistol grip angle. Cut two more longer pieces (pine or other hardwood NOT balsa!!) by at least 5 cm. These will be the two outside layers of the handle's laminate. Using 5-minute epoxy, glue the first lamination onto that center piece of the handle and let dry. Test fit onto the cut-down meter stick. Now, epoxy that half of the handle to the launch stick and clamp. When cured, epoxy the last side of the handle, clamp and let dry. When the assembly is cured (about 1 hour), drill small holes that go from the handle through the meter stick. Use some wood screws to secure the handle laminates. Do this from both sides (at least 2 per side). Trim any excess wood from the launch surface and sand smooth.

At the launcher's front tip, epoxy a piece of hardwood on the side with the grain perpendicular with the meter stick and 4X thicker than the screw eye shaft that you plan to use. Add wood screws to this as well when it is dry. The screw eye can be applied in parallel with the meter stick at the front end. this will be your attachment for your rubber loop.

I would also recommend not exceeding 1/16" cross section on the rubber loop. Any larger may induce a shock load of air on the front of the wings and cause damage. These lightweight gliders need a chance to have a graduated increase of speed before exiting the launcher. A loop made from a 12" strip (6" loop) is a good minimum size.

Midwest Products used to have a glider launcher- but it shows that it is "temporarily unavailable". Might be worth a phone call 800-348-3497

http://midwestproducts.com/products/tec ... r-catapult

Good Luck,
50 Missions (and counting)

[Bilbo McSwaggins]

Is there an advantage to a long launcher with a pistol grip handle on the bottom as opposed to a simple stick? Thanks in advance.

Other than having a more comfortable grip for your hand, there really isn't an advantage.

[Bilbo McSwaggins]

This may sound stupid, but I am building a 80 cm. launcher and can't find any printable rulers that I like. (they are all too small or hard to read)

Could you cut a meter stick or yard stick and use that in your launcher?

I don't think that would fit because my platform for the glider is to thin and I don't actually want to put it on top since that makes it uneven.

[reed303]

This may sound stupid, but I am building a 80 cm. launcher and can't find any printable rulers that I like. (they are all too small or hard to read)

Do you have an IKEA store nearby ? I have a freebie meter "stick" from them that is printed on thin paper. Or try a fabric store for the flexible ones used by tailors.

[fifty_missions]

This may sound stupid, but I am building a 80 cm. launcher and can't find any printable rulers that I like. (they are all too small or hard to read)

Could you cut a meter stick or yard stick and use that in your launcher?

I don't think that would fit because my platform for the glider is to thin and I don't actually want to put it on top since that makes it uneven.

Would you please attach a picture of this platform and glider? I think that those who want to give you assistance might be confused by your application.

BTW, the teams that have been making the highest flight times here in the midwest (30 seconds plus) are using a hand-held stick/handle arrangement that is much simpler to use. Some use a complex launcher with measuring devices in the beginning but once they get a "feel" for each glider, they use a simpler method that is less awkward in contests. I personally use a launcher that has a handle with a integrated stopwatch so that I can immediately activate the timing on launches. The method also allows my launch angles to be changed based on the specific launch idiosyncrasies that each glider tends to have saving time during trim flight periods. It also makes sense to write critical information about each glider in the log concerning various angles on launch. This is especially true when using a gaggle of multiple gliders. It is good policy to ID each glider with a "serial number" and whether it flies left or right and launch with left bank, right bank, etc.

A new SHARPIE marker is perfect for applying simple info to the wings of each glider. No more mysteries on the launch if you choose another glider to fly.

Good Luck,
50 missions (and still counting)

[bjt4888]

fifty_missions wrote:

Just a quick report on the Indiana State Finals. The ELG event was held in the Mellencamp Fieldhouse with a height of 60'. Thomas Jefferson MS won with all5 flights in excess of 38 seconds EACH. Their total score for 3 flights was 112. The second place team was 72. TJ would have won the event with just two flights. Thomas Jefferson won the overall IN State Competition and will be flying at Nationals in Nebraska (60' ceiling).

Congratulations on some good flight times. If you want to try a design that has very high capability, the Bill Gowen Cat II CLG AMA national record holder would be very good for this 60 ft. ceiling height. Bill's glider is of course a 12" projected span and 3" chord wing per AMA rules, so you could scale it up to the 32 cm SO span limit and add about .25 in. to the chord and have pretty much the same wing loading as a couple copies that my HS students constructed last year for an AMA contest after the SO state finals. My student's goal last year was to break the AMA Category III indoor CLG national record with this glider. Although they fell short of this goal, they did pretty good considering their gliders were only partially trimmed. They only had about 1/2 hr to trim their gliders at the contest and about an hour to get in official flights. The glider averaged 53 to 54 seconds per flight in a 62 ft ceiling site. Their gliders weighed 3.6 grams. At 4 grams and scaled up to meet SO rules this year the gliders would have the same wing loading and would perform the same 54 second flights. See the Hip Pocket Aeronautics Indoor Free Flight Forum for Indoor Glider for more description of building this glider under the thread "Cat 2 SCLG record glider". Bill's best flight in a 55 ft. ceiling site is over 60 seconds using a 3.1 gram version. Also, pictures and description of my student's gliders are in the Hip Pocket Aero thread named, "Gowen's Cat II Glider for Higher Ceiling". The plan is also posted on the Hip Pocket site in the plan gallery.

Good Luck and good flying,

Brian T.
AMA since 1972 (off and on)

[Bilbo McSwaggins]

Just wondering what the dimensions of the University of Nebraska's are.

[fifty_missions]

Just wondering what the dimensions of the University of Nebraska's are.

The University of Nebraska site will be inside their Cook Pavilion indoor football training facility that has a 60' ceiling and a footprint the size of a football field. Three events will be there, Wright Stuff, ELG and Air Trajectory.

Here is a link to the site-
http://crec.unl.edu/city/cook

Good Luck,
50 Missions (and still counting)