[NRV Rocketry] Questions about outfitting an avionics bay with power-safety flags

[Thomas Weeks]

On Wednesday, July 06, 2011 03:42:16 pm gus8 at vt.edu wrote:
> an E-bay is not required for level two certification. all you need is
> standard parachute recovery. the rule is that before attempting a L3
> certification you must fly a L2 rocket with an E-bay.
> check it out
> http://www.tripoli.org/LinkClick.aspx?fileticket=KFR2HOyfPfo%3d&tabid=132

Yuppers.. forgot about that.


> Active recover just means a method
> that changes the configuration of the rocket. so the standard ejection
> charge on top of the motor separating the rocket counts.

Yes, that's right... I was thinking of my old mentor Art Applewhite's saucers 
(from San Antonio). He's kind of an anti-3fin/4-fin guy who like creatively 
side-stepping all the regs. His new "level-2 saucer" does it's "config change" 
by flipping out a pirce of scrap fabric he calls his "Moustache" Active 
Recovery Device. .. effectively "changing the configuration" for qualifying 
for L2. :)
	http://www.artapplewhite.com/l2.html

I actually need to prepare my e-bay because running my Talon-3 through the 
simulator with a J Pro38 puts it up around 3500 ft. Not something I want to 
chase a couple of miles on a breezy day. ;)


> if i did it, which i have never done i am just getting started myself,
> i picked up a LOC vulcunite kit that can handle F-J so i can do my L1
> and L2 i i want,

Cool! This the one?
http://www.hobbylinc.com/htm/loc/locpk52.htm

Good looking 3-fin!

> i would go with the exterior switch, something small
> from radio shack that wont cause much drag.

Yes.. I may ned up doing that (or the rotating-leaf power supply (110/220) 
power switches... but I was just trying to avoid any protrusions.. or a config 
that would take a "special tool" to arm and disarm.

I was just wondering if anyone had any related "no-nos" such as the audio jack 
based switch or not.

Tweeks

> 
> -Gus
> 
> > This is a question for you high power guys who have been shooting H and
> > up birds for years.
> > 
> > Background:
> > -------------
> > So my first HP rocket is about ready to fly... and I plan on using it to
> > get my L1 (H) and L2 (J) certifications. The L1 is no problem. Up, pop,
> > float down. But as most of you know.. L2 certification also requires a
> > written test (no problem) as well as "Active recovery", or a way of
> > measuring your altitude
> > and ejecting multiple chutes at precisely the right times to safely
> > recover my
> > rocket.
> > 
> > Well.. I've now mostly built my avionics bay, or "e-bay" and wired in a
> > GWiz LCX flight computer:
> > http://www.facebook.com/photo.php?pid=1049573&l=3b9cc7e689&id=1844028171
> > http://www.facebook.com/photo.php?pid=1052820&l=fde4de7d63&id=1844028171
> > http://www.facebook.com/photo.php?pid=1052821&l=8f9d1e56c2&id=1844028171
> > http://www.facebook.com/photo.php?pid=1052825&l=878029acee&id=1844028171
> > http://www.facebook.com/photo.php?pid=1052823&l=079bcf0bff&id=1844028171
> > http://www.facebook.com/photo.php?pid=1052824&l=d39d643ca4&id=1844028171
> > 
> > Here are some other pictures of other people's e-bay construction and
> > products:
> > http://www.vanderbilt.edu/USLI/2011/media.php?gallery=jan_19_2010
> > http://www.apogeerockets.com/electronics_bays.asp
> > http://www.rocketryplanet.com/content/view/2960/95/#axzz1RIL7aYxk
> > 
> > 
> > My Question:
> > -------------
> > Anyway.. my question for Bob and other experienced Rocketeers..
> > 
> > What should I use for my flight computer's power safety switch?
> > 
> > So you're supposed to have a power arming safety circuit to ensure that
> > your ejections charges don't blow before you launch the thing... They
> > usually look something like this:
> > 
> > http://aeroconsystems.com/cart/products/RBF4-47-10.html
> > 
> > And are hung off something like a 1/8th " audio jack (where the normally
> > closed circuit is open when the audio plug is in... and removing it
> > completes (or closes) the circuit.. and powers up the computer). 
> > However.. I hear that the flight vibration can really make those switch
> > contacts bounce around, which can reset the flight computer.. which
> > leads to big expensive crashes. So
> > a lot of folks use these high-G rated switches like this:
> > http://aeroconsystems.com/cart/products/PCB_Screw_Switch-110-0.html
> > or
> > http://www.aeroconsystems.com/electronics/switches.htm
> > 
> > Not nearly as cool/sexy as the "yank it out" audio plug that I want
> > to use. :)
> > 
> > 
> > So what do you other HP folks recommend? Slide switches? Hard wired
> > toggles? Audio jack/plugs?
> > 
> > Tweeks
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