Re: Floater balloon

Bill Brown
 

Bruce. No more than 3 grams free lift. But if using two Mylars you can use 3 grams of free lift each. I have never tried to do a Mylar 36-inch with that heavy of a payload. My heaviest successful floater was about 22 grams i believe. Use Qualatex brand. There is a spreadsheet by the UKHAS folks for predicting float altitudes   I can email u after work. - Bill WB8ELK


On Aug 28, 2018, at 7:29 AM, Bruce Coates <bruce.coates@...> wrote:

Hi

I'm planning on launching a floater balloon from Saskatoon in the near future and it just occured to me that i know just enough to be damgerous.

My payload  is complete and weighs in at about 40 grams, quite a bit heavier than i had hoped. I have 36 inch mylar balloons which should provide over 75 grams of neck lift if they were fully inflated with hydrogen.

I have just 3 questions:

1. Given the mass of the payload, how much net lift should I use?  I'm thinking of 5 to 10 grams. 
2. How do I run predictions for a floater?  Given my northern latitude, I want the initial part of the flight to travel southward over southern Canada or the US so I can track it for the first part of the flight.
3. What other questions should I be asking?

I'm all ears.

73, Bruce - VE5BNC

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