High altitude question from a newbie

Large high aspect ratio fixed fins.

Tech Jerry

Consultant?

Well... ONE fin, anyway. Make it a weathervane, pointing in the direction of the wind. ;-)

"Len Lekx" a écrit dans le message de news: snipped-for-privacy@4ax.com...

Wouldn't fin or fins be useless as the relative wind is zero when the balloon travel at the speed of wind. Maybe an active stabilisation system with a light cell or a gyroscope?

How about a horizontal axis gyroscopic flywheel?

-consultant and employee - to a company with less than two employees.

8-)

Spin damping paddles. Affix 3 radial booms to your payload package (spaced

120 degrees apart) each with 1 vertical and 1 horizontal 'paddle' at the end of the boom (in a cross formation) to counter any tendency to spin and/or rock. For a small package try 1/2" balsa sticks for the booms, and 1/32" balsa sheets for the paddles. The larger the paddles & the longer the booms, the greater will be the damping effect.

Good call.

Unless you're trying to get a really stable platform for your experiments, spinning isn't too big a problem in most high altitude balloons, atleast on the way up. Descending is another story...

Also, I'd suggest putting a swivel in your flight line to prevent twisting.

Dave

Hadn't considered that... good point. :-)

Without wind-motion, though, you'd need a gas-thruster system for the gyros or sun-sensors to drive.

There is turbulance (wind speed and direction changes) and a baloon is a slow mover so relative wind on a momentary basis can be high.

Jerry

This is how it's done. Check out

Bob Krech

Thanks for the pointers and the great ideas everyone. I like Vince's idea, I will be looking into doing that soon. As far as the Vaisala kit goes, great for soundings etc, but rubbish at staying steady, they pretty mush go where the heck they like. Interesting idea about the gyro too, food for thought that one.

I will be coming back later to ask more questions I'm sure. Next project is some form of autopilot for a glider carrying the payload, to return it to the launch location instead of driving all over the place looking them.

Thanks again

Bads

Point :)