Building a small hot air balloon

[LightningInAJar]

How high do you want to go? Could you rig up a kite? You already have the string...

Maybe 4 or 5 stories high.

 

[russ_watters]

Maybe 4 or 5 stories high.

See post #6. But check the spool/twine.

 

[gmax137]

Back in the 1960's, some college students in Appleton, Wisconsin found that a dry cleaner bag would lift a candle. The candle provided enough heat to lift the bag and candle, plus enough light to generate UFO reports.

Oh, memories. My friends and I did this, around seventh grade. I don't remember where we got the idea. We used two crossed balsa sticks to hold the bottom of the bag open. Scotch tape to seal the openings in the top of the bag. For heat, we fashioned a small dish out of aluminum foil, and taped it to the center of the sticks. Fill dish with denatured alcohol and light.

Well if he was going hunting, you'd think he would have used better-camoflaged baloons!

I'm sure the pellet gun was for popping his balloons one by one when he wanted to descend.

I would think they are fire hazards and should not be set free at all.

We had a slight crosswind during our final dry-cleaner bag flight. The balloon was carried into the top of a large pine tree in the neighbor's yard. We watched it for about an hour, afraid we had set the tree on fire. I lay awake that night listening for fire trucks.

 

[LightningInAJar]

Do they have RC hot air balloons? I would like to avoid hydrogen for sure and helium because of difficulty getting it and the quantity of balloons needed to get a meaningful amount of lift. Would heating air make a big difference compared to lighter gases alone? My 360 camera actually is pretty light.

 

[anorlunda]

Do they have RC hot air balloons?

You could certainly make your own.

Are you ignoring the warnings about fire hazards? I think that would be very unwise.

Here is a story about an attempt to use them as terror weapons.
https://www.history.com/news/attack-of-japans-killer-wwii-balloons-70-years-ago

 

[bob012345]

Do they have RC hot air balloons? I would like to avoid hydrogen for sure and helium because of difficulty getting it and the quantity of balloons needed to get a meaningful amount of lift. Would heating air make a big difference compared to lighter gases alone? My 360 camera actually is pretty light.

Have you really checked on the difficulty getting Helium? Do you know you can't get it at some local store?

 

[sophiecentaur]

Have you really checked on the difficulty getting Helium? Do you know you can't get it at some local store?

Most high streets have Party Supply shops. You can even buy them in my local village card / toy shop. Afaiaa, there are very little special restriction involved with 'balloon gas'. Just ask around.

 

[anorlunda]

Larger balloons are inexpensive and easy to find, for example this one I found on Amazon. The one in the picture claims to be able to lift 500g, for just $17.

Helium can also be bought locally in most places.

 

[berkeman]

Thread closed temporarily for Moderation...

 

[berkeman]

I think we've addressed the OP's question fairly well, and pointed out the dangers of trying to use fire to heat air for an uncrewed vehicle. The OP may live in an area where wildfires are not a concern, but here in the Western US and many other places, wildfires have been increasing in number and severity over the past decade or so. Since many readers of this thread in the future will be from such places with high fire danger, it's inappropriate to have any further discussion on the topic.

Stay safe folks, and be smart in your projects.

https://www.teenvogue.com/story/california-wildfires-why-happening