Launch day - Filling the balloon
In this tutorial we’ll look at filling the balloon.
SOME THINGS TO BE AWARE OF:
- Balloons are delicate, use a ground sheet
- Make sure there is nothing that could burst the balloon near enough for the balloon to hit
- There are various kinds of valve available
- Be careful with fingernails (we often use latex gloves to handle the balloon)
Our preferred method involves using a hose (available here) to connect the valve to the balloon for freedom of movement. It makes handling the balloon much easier.
Tape the hose to the valve at one end and fold the balloon neck around the other end and hold securely.
Release the valve to let the helium flow into the balloon (most valves either push in or bend to the side). A second person controlling the balloon is a good idea (especially if there is a breeze – it’ll help to stop the balloon bobbing about too much whilst filling).
The best method is to use our digital filling scales to measure the lift force. Tie a loop of string around the balloon neck and through the rounded ring on the scales. Keep hold of the other end (or attach it to the ground) and then look at the lift force changing until the right amount of pull is reached. Use the calculator to find out what lift force the balloon should have. The lift force needed is equal to the Free lift plus the weight of your payload (including all extras such as cord and parachute).
Another way is by balloon diameter (or circumference). Take some string cut to the “launch diameter” and once it fits around the middle of the balloon you know you’ve got the right amount of gas. (again – see calculator).
TYING OFF THE BALLOON
This is the most reliable method we’ve found for tying off a balloon.
- Fold the neck back on itself and tie off again to form a loop.
- Use strong tape around the top of the loop.
- Feed the cord (that connects to the parachute) through this balloon loop and tie off.