Discussion Solar balloon free flight contest

[peter_ashland]

Here is a quick prototype of the panel. I used tape on the vents and just cut the scallops.

It looks like it should have no problems staying shut or opening. The seam should keep it working fine and it does not look leaky.

[catman529]

assuming that the 2nd picture is an inside view, your vent looks great. You could do a large one for the top as well.

Pulling the vent open won't collapse the balloon, it will just make a small indentation. Just pull enough to get the vent open without pulling it shut

[peter_ashland]

Originally Posted by catman529

assuming that the 2nd picture is an inside view, your vent looks great. You could do a large one for the top as well.

Pulling the vent open won't collapse the balloon, it will just make a small indentation. Just pull enough to get the vent open without pulling it shut

I am afraid it does in my limited indoor test. The extra material and rope cause the balloon to fold over that spot when the balloon is weakly inflated. But it looks like this may only be a problem when the balloon is on the ground. I will tie the valve control rope to an elastic attached to the balloon to support it for the ground teather test. It should be OK.

The servo control of the ballast is going well. I hacked a servo into a drive motor and made a candy bar style dispenser. I will drop envelopes with a couple ounces of birdseed. The tops of the envelopes will be open so hopefully the seed will just dump out on the way down. But I may just tie the bottoms of the envelops to a string on the balloon or even a streamer for effect.

The valve control will be a hacked servo winding the valve rope to open it. I am a little worried about how to spool the valve rope back out if the valve flap doesn't have much tension on it.

I am aching to get out and do the tether tests to verify the ballast weight. I am building the device to carry at least 2 lbs. But I doubt I will need that much birdseed.

[mlbco]

Catman529,

I checked out your solar balloon site and built a 6 ft Tetroon based on your instructions. I could only find 0.6 mil bags, so it was a little heavier than recommended. Went out to the park with it this morning and waited for the sun to poke through the clouds. I used a mattress air pump to inflate it (took a while to fill up) and then let it bake in the sun. Unfortunately, the wind was also picking up and would cool the balloon reducing the buoyancy. Eventually, it seemed to be tugging upward and I released it. It climbed 15 feet and drifted across the soccer field, "rolled" over a tree line, and appeared to be lodging itself in another tree line when suddenly it began to rise. The climb rate was slow and I jumped in the car and chased it for a couple of miles. Pretty soon it was above cloud base (1500-2500 ft?) and still climbing. I watched it through binoculars until it vanished in the NW breeze. Overall, a very exciting experience. It would be nice to have a cheap way of tracking these balloons to get some idea of how high and far they go. Next time I might just add some mylar for longer visual tracking.

Steve

[catman529]

Originally Posted by peter_ashland

I am afraid it does in my limited indoor test. The extra material and rope cause the balloon to fold over that spot when the balloon is weakly inflated. But it looks like this may only be a problem when the balloon is on the ground. I will tie the valve control rope to an elastic attached to the balloon to support it for the ground teather test. It should be OK.

The servo control of the ballast is going well. I hacked a servo into a drive motor and made a candy bar style dispenser. I will drop envelopes with a couple ounces of birdseed. The tops of the envelopes will be open so hopefully the seed will just dump out on the way down. But I may just tie the bottoms of the envelops to a string on the balloon or even a streamer for effect.

The valve control will be a hacked servo winding the valve rope to open it. I am a little worried about how to spool the valve rope back out if the valve flap doesn't have much tension on it.

I am aching to get out and do the tether tests to verify the ballast weight. I am building the device to carry at least 2 lbs. But I doubt I will need that much birdseed.

Don't know what the prob is with your vent, but I just built 2 on my balloon, along with a velcro parachute vent, and they work fine, Maybe I could show you pics - so far all I got is a couple shaky videos. Hope this turns out well. And I don't think your balloon will hold nearly 2 lbs. If this doesn't work out, try the 10-foot tetroon. but I hope you get it all to work soon, cuz I want to see this thing in action

Originally Posted by mlbco

Catman529,

I checked out your solar balloon site and built a 6 ft Tetroon based on your instructions. I could only find 0.6 mil bags, so it was a little heavier than recommended. Went out to the park with it this morning and waited for the sun to poke through the clouds. I used a mattress air pump to inflate it (took a while to fill up) and then let it bake in the sun. Unfortunately, the wind was also picking up and would cool the balloon reducing the buoyancy. Eventually, it seemed to be tugging upward and I released it. It climbed 15 feet and drifted across the soccer field, "rolled" over a tree line, and appeared to be lodging itself in another tree line when suddenly it began to rise. The climb rate was slow and I jumped in the car and chased it for a couple of miles. Pretty soon it was above cloud base (1500-2500 ft?) and still climbing. I watched it through binoculars until it vanished in the NW breeze. Overall, a very exciting experience. It would be nice to have a cheap way of tracking these balloons to get some idea of how high and far they go. Next time I might just add some mylar for longer visual tracking.

Steve

glad to hear .6 mil bags will fly on such a small balloon! I had one incident in VA where I let go a real tiny balloon (0.5mil) and it went toward the closest mountain. Then it started dropping lower, lower, until I lost sight of it behind the trees. Drat, I thought it was done. Then a couple minutes later, it popped up again and flew up and away till I couldn't see it anymore.

and yeah, I also wish there was a cheap way to track the balloons. best thing I can do is stick a tag on and hope someone finds it, but that doesn't tell me exactly where it flew and how high it went. but someday, I would like to do the whole GPS thing with a big one.

good luck flying

[mlbco]

Here are some pictures of my balloon before vanishing.

Steve

[catman529]

Originally Posted by mlbco

Here are some pictures of my balloon before vanishing.

Steve

sweet!

if you want to enter the contest, sign up, you may have a chance of getting a reply someday...since you are in CA and the jetstream moves east, you can release early on a cold morning, and it may get high enough and go halfway across the country...it's possible

[mlbco]

Here's some pictures of my contest entry solar balloon launch. Notice I added a "payload" to entice whoever finds the balloon into picking it up. Now we'll have to see if anyone ever finds it!

Steve

[catman529]

wow, those balloons look great! If anyone finds them, I'll get an email. But I'm not telling anyone if their balloon is found until the end of the contest

I love the pic with the balloon and the 747...hope one doesn't get hit
keep up the good work.

tomorrow will be sunny here but also very windy, the day after though might be a great day for releasing. I'm afraid I release mine too early in the morning and they are ending up in the sea, because I haven't had any returns in a long time...

[jwfinn]

Originally Posted by catman529

but someday, I would like to do the whole GPS thing with a big one.

Another alternative would be to put a Walston transmitter on the balloon. Only trouble is that they are pretty expensive. Their long range rocket retrieval transmitter has a range of over 90 miles line of sight and only weighs an ounce.
http://www.walstonretrieval.com/main.htm

Someone with a pilot's license could go out West, launch in the morning, and follow the balloon back. It would take some careful planning to get the right set of conditions so that the balloon would hit strong winds at altitude.

[catman529]

Site update:

check out the new site design....I finally moved over all the content onto the new template. yes, I made the template

www.solar-balloons.com

[mlbco]

I made a crude spherical with a 3 ft radius and released it Saturday. Here are some pictures. It flew about 1/2 mile East and then reversed direction as it continued to climb. I lost sight at after 30 minutes.

Steve

[catman529]

once again, looks great. even if its crude, it can still fly purty far... hope at least one of those is found

Originally Posted by mlbco

I made a crude spherical with a 3 ft radius and released it Saturday. Here are some pictures. It flew about 1/2 mile East and then reversed direction as it continued to climb. I lost sight at after 30 minutes.

Steve

[busta1]

who's going to make one big enough to do some solar balloon jumping ?!??!!! I have thought about giving one try

[mlbco]

I'm too lazy to build a balloon big enough to lift me, but here are some pictures of the biggest balloon I built. I used 20 garbage bags and I think it was 15 feet tall. Does anyone know where to buy 0.7 mil black plastic on large rolls? That's what I need to build big balloons. Taping garbage bags together gets very boring.

Steve