Tethered Weather Balloon Help - RC Groups
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Apr 07, 2017, 04:46 PM
Registered User
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Tethered Weather Balloon Help


Hi all,

I am looking to deploy a tethered weather balloon for a project. The goal is to have the balloon stream video data back to a ground-based control. The balloon should be relatively stable, although elevation and position do not have to be static. Expected height of flight will be in the ballpark of 300ft. It would also be nice for the balloon to be reusable and made of a sturdy material.

Things I need help with:

- balloon material: it seems that latex is not good because it is vulnerable to puncturing / scrapes
- helium tank: what brands are good / where can I fill and refill these?
- tethering material and how much of it is needed
- how to retract the balloon? are electronic winches the best option, or are there cheaper alternatives?

Thanks!
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Apr 08, 2017, 07:15 PM
Melbourne, Australia
I've only messed around with free floating weather balloons, but I'd start with the standard latex ones. They're not that easy to puncture until they're fully inflated, so don't fully inflate it :-). I think we had a 500g balloon, inflated with a couple of cubic meters of He, and at ground level the rubber was still quite thick and relatively strong. Don't drag it through gravel or haul it through trees, but it will bounce off buildings and people unharmed. Also they're cheap.

You don't say how big your payload is; if it's a light camera you might be able to get away with a smallish balloon, in which case maybe a simple kite spool or fishing reel might do the trick? A 100m of decent fishing line might work... should be fairly cheap to try out anyway!

Good luck!
Apr 12, 2017, 02:29 PM
Registered User
Hi pegacat,

Thanks for your response!

My payload will be roughly 1300g. Do you have any other tips for tethering material? I am looking to fly this under fairly strong wind conditions.

Thanks again!
Apr 13, 2017, 02:00 AM
Melbourne, Australia
It would be easy to run a trial - just grab a (say) 500g weather balloon and inflate it with ~2m**3 of He, attach (say) a milk bottle filled to 1300g weight with water, and see how you go. 100m isn't unreasonably long, so I'd try 'heavy' fishing line - e.g. looks like you can get 1mm dyneema line with a weight limit of ~90kg from amazon, back of the envelope it should be about 1g per meter, so won't affect your weight limits too much. I'm not really a fisherman, but I gather they've got some pretty sophisticated reels 'n stuff for letting it out and reeling it in :-).

Just make sure you have some sort of anchoring system so it doesn't get away from you!
Apr 17, 2017, 02:23 PM
Registered User
Thanks pegacat,

I bought a weaker (~6kg) fishing line and will run a scaled test with a small store-bought prefilled helium balloon.

I plan on doing this test at the top of a small hill, and I don't want to make the trek up there with a helium tank just yet
Apr 18, 2017, 01:57 AM
Melbourne, Australia
Excellent - just be careful; depending on how big your balloon is, a stiff breeze may exceed your load limit :-). (Also small 'toy' balloons have a lot less lift; so a few grams from your fishing line may be significant - although I think 6kg line is ~0.25mm? So should be fine. Maybe weigh it first...)
Apr 20, 2017, 10:58 PM
Registered User
Thanks pegacat,

Do you know if there is any difference between an Argon tank like this one: https://www.amazon.com/gp/product/B0...960_em_1p_0_ti
versus one made to hold helium?

The only difference I can imagine is that 60cuft of Argon has a different amount of pressure versus 60cuft of Helium, seeing that they are both otherwise inert gasses.

Thanks for your help!
Apr 21, 2017, 08:22 PM
Melbourne, Australia
Well the description says it works for Helium :-).

I think they're all pretty much the same aren't they? I'm not really a tank expert - here in Australia you usually 'rent' the tank from your gas supplier and take it back to swap it when you're empty. Might be best to talk to your local gas supplier...