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Unwinder Design

Steve G8KHW / AJ4XE
 

Hi folks - I'm looking for a home-brew unwinder (AKA dereeler) design - I've got a launch to do with a limited launch area and I really need to use an unwinder.

Ive seen the designs for the Vaisala and Graw types:

https://thumbs.worthpoint.com/zoom/images2/1/1211/08/radiosondes-graw-wettersonde-vaisala_1_3e397dd9892d5593c9e63aaa15175970.jpg

https://www.vaisala.com/sites/default/files/styles/product_main/public/images/PROD-RS41-1280x960.jpg?itok=OVS1SLYA

https://www.graw.de/fileadmin/cms_upload/Images/Unwinder_UW2_1024x768_72dpi.png

https://www.graw.de/fileadmin/cms_upload/Images/Unwinder_UW1_1024x768_72dpi.png

My first attempt to make my own was a bit of a failure.   Any sure fire, simple designs out there?   My payload is about 100g (3.5 oz)

    Steve G8KHW / AJ4XE







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James Ewen VE6SRV
 

The second link you posted is about as simple as it can get. Just wind the string around a flat form and let go. 

The string unwinds as the balloon and payload rises. Simple and easy to use. 

On Sat, Jun 20, 2020 at 3:51 PM Steve G8KHW / AJ4XE <steve@...> wrote:
Hi folks - I'm looking for a home-brew unwinder (AKA dereeler) design -
I've got a launch to do with a limited launch area and I really need to
use an unwinder.

Ive seen the designs for the Vaisala and Graw types:

https://thumbs.worthpoint.com/zoom/images2/1/1211/08/radiosondes-graw-wettersonde-vaisala_1_3e397dd9892d5593c9e63aaa15175970.jpg

https://www.vaisala.com/sites/default/files/styles/product_main/public/images/PROD-RS41-1280x960.jpg?itok=OVS1SLYA

https://www.graw.de/fileadmin/cms_upload/Images/Unwinder_UW2_1024x768_72dpi.png

https://www.graw.de/fileadmin/cms_upload/Images/Unwinder_UW1_1024x768_72dpi.png

My first attempt to make my own was a bit of a failure.   Any sure fire,
simple designs out there?   My payload is about 100g (3.5 oz)

     Steve G8KHW / AJ4XE







--
This email has been checked for viruses by AVG.
https://www.avg.com




--
James
VE6SRV