Wing Tip Discus Throw Hand Launcher

by dharkless | May 4, 2015 | (8) Posted in How To

This article shows how to install and use a device on the wing tip of smaller models that allows you to hand launch safely and easily without assistance.  The device is a simple short piece of dowel or skewer that is glued into a hole through the wing tip with a gift card or cutting board reinforcer on the bottom side of the wing.  The dowel is long enough to project 1/2" above and below the wing surface.  It is placed approximately 1/2" from the wing tip and approximately at the wing spar or CG.

Here is a picture showing the top and bottom sides of the installation:

The top side is on the right.  

You start by marking the location.

 It should be at the center of the thickest part of the wing and 1/2" from the wing tip.


Then take a pointed skewer and start a hole from the top till just the very tip pierces the bottom paper.


Then go from the bottom and push through to finish the hole.


Next cut a piece of skewer 1 1/4" long.


Use a sanding block to slightly taper both ends.  


Spread a generous ring of glue around the dowel at a point slightly below the center.


Next insert the dowel from the top and push it down slowly with a strong twisting motion.  

The dowel should make two or three full rotations as it approaches the center (1/2" up and 1/2" down).  The tristing will distribute the glue in a neat donut shaped ring around the top side of the dowel.  Do not disturb this shape.  Make sure the dowel is straight and let the glue set.

While the top glue is setting cut a 1" square of gift card or cutting board material.  


Drill a hole a little off center just big enough for the dowel to slip easily through.  


The trial fit looks OK.


Trim any rough edges from the hole with a knife.  Spread a generous coating of hot glue on one side of the square.


Then slip it over the bottom end of the dowel and press it firmly to the bottom surface of the wing.


Finally, apply a light even bead of hot glue around the bottom of the dowel where it exits the reinforcer.


If you did everything right the dowel should be square with the wing surface top and bottom.  It should extend about 1/2" above and below the wing.

The reinforcer should be about even with or just short of the wing tip with a full bed of glue between it and the wing surface.  

There should be a neat donut of glue around the dowel on the top of the wing and a somewhat less neat ring of glue at the bottom. The dowel should feel secure in your hand.       



The fingers are held loosely in a Cub Scout salute (index and middle finger extended) with one finger above and one below the wing behind the dowel.  

The plane is held hanging down hehind your back with your body rotated about 90 degrees backwards. The plane is revved up and then allowed to pull around to your side with your hand guiding it into level flight. From the starting position to the release is about 90 degrees of rotation. The plane more pulls itself off your hand than you throw it.  Your arm should follow and guide the plane till it and the plane are parallel to the ground and straight out to your side.  The plane will pull itself off your still loose finger tips and be off in level flight straight in front of you.  Heavier planes may need a little "push" but for the most part the motor does the work.  You should have your left hand on the throttle through the launch. If the palne is reasonably balanced you will have time to get your right hand to the controls before anything bad happens.

Note: The wing shown is from my "Not So Tiny Trainer" (see article by that name in related atricles below).  It has a 48" wing span and is about the upper limit of what is practical for this launching method.     


apnewton on May 16, 2015
Nice article and a cool idea. 5 stars
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dharkless on May 16, 2015
Thanks for the kind comments and the rating.
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ashtodust2000 on May 16, 2015
What would be the advantage of this over just grabbing the end of the wing?

You can't discus launch it, it will rip off the wing, without some sort of wing strengthener.
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dharkless on May 16, 2015
I believe the grip is easier. You have more control with less effort. I suppose you could just grab the wingtip but I have never seen anyone do that at the field. Most hand launches I have observed have been done by a helper and usually by grabbing the fuselage. This is an easy and reliable way to launch without help, as I stated above.

The "Discus" description refers to the general posture when launching, not the details of the launching method. A discus launch in gliders is different from a discus throw of a discus. There is only one full rotation in the demonstration given by David in the article referenced above whereas a real discus throw is usually two full rotations. A discus launch of a power plane is different from either in that a full rotation is not needed. The details in the article indicate that it does not need to be thrown with force.

I have launched many times using this technique and have never had a wing fail or become dislodged. The wing does not need any special reinforcement or attachment.
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ashtodust2000 on May 19, 2015
Thank You for the reply, Makes sense to me now.
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dharkless on May 19, 2015
Thanks for the question. It gave me an opportunity to clarify a point that might have been vague in the article. Readers comments almost always help to make the quality of the articles better.
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Raycefan on May 24, 2015
Never really thought much about gliders, then it's been abnormally windy here in Alaska this spring. Now I'm looking at investing in at least one hand launcher and this seems to be the way to get the longest flight times. Thanks for the instructions!
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dharkless on May 26, 2015
This article was intended primarily for small powered airplanes. The original discus launch method shown in the FT article listed in related articles above is for high performance gliders that are designed for this launching method. You would probably not get satisfactory launch heights with the discus launching method with other gliders. Bungee launching might be more suitable.
This method would be suitable if you had a glider in a slope soaring situation.
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Wing Tip Discus Throw Hand Launcher