How To - Simple Bungee Launch Set-up

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How-To
April 2017

 



Introduction

Several have asked how I launch my wings and the answer varies depending on the wing, the weather and the location. One method I use and really like is this simple launch set-up which, so far, has worked flawlessly. I previously used a ramp with a launch trigger but I found that carrying this extra gear around was a pain. I then saw a fellow RCG poster do it this simple way and gave it a try.

The Gear

The gear is simple enough:

12' (3.5m) braided poly chord
33' (10m) HobbyKing Red 6mm Bungee Chord
1-1/2" (40mm) Key ring
A stake to pound into the ground



Bungee.JPG



Layout

A few knots and you are ready!

BungeeLayout.jpg



The Hook

The hook can be simple and it must be pretty small. Below is a picture of the hook on my C1 Chaser wing which is very low profile:

C1 Hook.JPG



This style of hook will work on just about any airframe and for this type of launch it should be well ahead of the CG. In the case of the C1, it is about two thirds the distance to the nose.

Setup and My Method

The setup is simple, put the stake in the ground and make sure you have enough flat, level space to launch into the wind.

My Method:

  • Set your FC to a stabilized flight mode with about 20% up elevator (I program a switch for this)
  • Have your transmitter on a neck strap or in a buddys hands so you can use both hands for the launch
  • Hook the key ring to the launch hook and walk back till the pull is about 3 to 3-1/2 times the planes weight. 20 paces is perfect for my ~880g C1 wing
- The amount of pull can be adjusted lower (less paces) after you find the first few go well
  • Make sure the bungee is pulling the plane into the wind
  • Hold the plane at eye level or higher, pointed up just slightly and let it go
  • As soon as the plane is clear of the chord, throttle up and fly!



Updates

I have added a couple pieces to the set-up to help keep the surgical tubing in good shape and get it to last longer.

First I added a a pair of printed tubing savers that keep the tubing from stressing to much where it attaches to the chord:

Bung2.JPG


You can download the STL for this here: Bungee Saver

Another addition was finding a cloth bag I could easily wrap it all up in to prevent "shop damage" as even the tiniest nick can become a fail point:

Bung5.jpg



Video Samples

And now - the C1 Chaser launch!:


Enjoy!





And here is one from my Strix Stratosurfer:


Enjoy!




See Also

How To - Build a Mobile Launcher