Ballooning at Liverpool Makefest and Lessons Learnt.

 

So this could win the award for the most overdue blogpost ever. Back in summer I attended Liverpool Makefest as a maker and showed off lots of flying stuff under the title "Concretedogs Flight Lab", which coincidentally is also the title of book of projects I've been not finishing for a long time! One of the activities I showed and told at Makefest was my DIY Hot Air Balloons.

I originally wrote about these ideas back in Hackspace Magazine Issue 61 where I talk about their construction. As most councils have quite rightly banned the use of fire filled disposable balloons the approach here is to heat the balloons to perform shorter hop like flights and, when indoors, use a light kite line as a tether.

Previously I'd heated the balloons having an assistant hold them up and I fill them from the base with a single electric heat gun. But in an attempt to create more lift for this event I made a chimney from a meter length of vitreous enamel pipe into which fed 2 electric heat guns. It definitely makes more lift but I think the concept could be improved a lot. One of the issues is that the air is constantly moving and being pumped into and out of the balloon. It would be better to have less movement of the hot air and more heating! One possible solution would be to have a series of baffles in the chimney so that it creates more heat and less airflow. The other option I'm still really keen to try on a calm day outdoors is using a camping stove in the base of the chimney to get a high temperature whilst not creating a moving column of air.

The other challenges are the tether, there is of course the challenge of keeping the tether light and as altitude increases the weight of the tether becomes more apparent. Another problem I had at Liverpool was that if the tether snagged (usually on me!) this would cause a jerk in the line and often, especially when the balloon was quite high with a lot of tether weight, the balloon canopy would tear. I'm planning to run some experiments with a small length of really lightweight thin shockcord/elastic at the balloon end to try and mitigate this problem.

Wrapping up, this activity was great, loads of people mentioned that they wanted to try it and lots of people were entertained by the site of the balloons. It really is a lot of fun for a couple of quids worth of materials!