At 09:26 PM 7/12/2004 -0700, Mike wrote:

>Actually the "ignition" and "apogee" are both switches, yes apogee is a mercury tilt switch.

You are aware of the effect of burnout deceleration, right?

Some folks use mercury switches for staging, with the contacts pointed "up". When the booster burns out, "up" becomes "down" for a moment, and the next stage gets ignited.

Years ago, I did something like this, with a three axis fluxgate compass.  Capture "north" at launch, and renormalize so that 0,0,0 = up.  Now you can know airframe attitude and rotation, as fast as you can read the fluxgate. Real north dosen't move, so if it appears to, you must have rotated.

Also, use an aluminum launch rod!

--
http://www.piclist.com hint: The PICList is archived three different
ways.  See http://www.piclist.com/#archives for details.