Aerotech F39's - Which delay is right?

Aerotech F39's - Which delay is right?

Post by Sams Famil » Sat, 16 Mar 2002 08:34:37



OK, I got me some 1/2 priced F39-12's from Valueland's closeout sale.  But I'm
befuddled by the double markings. Which delay is closer to the truth? The -12 or
the parenthetically included NAR certification delay of 9 seconds?

At the time of the NAR cert test, I'm sure the -9 was correct, but did Aerotech
ever get around to adjusting the delay to be the indicated 12? Or is it because
of a difference in when the test equipment determines motor burnout and starts
counting the delay?  Which number should I assume?

Three seconds delta is enough for a zipper or shred, so your good advice will be
a big help.

TIA.

Doug

See my Sunday-go-to-meeting-hat at
http://home.flash.net/~samily/DougsRockets/ConeHead4.html

--
samily at flash dot net

 
 
 

Aerotech F39's - Which delay is right?

Post by Jerry Irvin » Sat, 16 Mar 2002 08:43:18




Quote:
> OK, I got me some 1/2 priced F39-12's from Valueland's closeout sale.  But
> I'm
> befuddled by the double markings. Which delay is closer to the truth? The -12
> or
> the parenthetically included NAR certification delay of 9 seconds?

This is definitely a question for Aerotech direct.  I would guess 9 but
this one is random.

Quote:
> At the time of the NAR cert test, I'm sure the -9 was correct, but did
> Aerotech
> ever get around to adjusting the delay to be the indicated 12? Or is it
> because
> of a difference in when the test equipment determines motor burnout and
> starts
> counting the delay?  Which number should I assume?

> Three seconds delta is enough for a zipper or shred, so your good advice will
> be
> a big help.

> TIA.

> Doug

> See my Sunday-go-to-meeting-hat at
> http://home.flash.net/~samily/DougsRockets/ConeHead4.html

--
Jerry Irvine, Box 1242, Claremont, California 91711 USA

Please bring common sense back to rocketry administration.
Produce then publish.

 
 
 

Aerotech F39's - Which delay is right?

Post by Christopher Dee » Sat, 16 Mar 2002 11:05:49


I haven't flown any F39-12s, but based on the 6s & 9s I've flown and seen, I
would say the NAR numbers are correct. My clubs experience has been the
stated Aerotech numbers for the F39s are about three seconds short. YMMV

--
Christopher Brian Deem       NAR 12308 TRA 2256 Level II

Quote:

> OK, I got me some 1/2 priced F39-12's from Valueland's closeout sale.  But
I'm
> befuddled by the double markings. Which delay is closer to the truth?
The -12 or
> the parenthetically included NAR certification delay of 9 seconds?

> At the time of the NAR cert test, I'm sure the -9 was correct, but did
Aerotech
> ever get around to adjusting the delay to be the indicated 12? Or is it
because
> of a difference in when the test equipment determines motor burnout and
starts
> counting the delay?  Which number should I assume?

> Three seconds delta is enough for a zipper or shred, so your good advice
will be
> a big help.

> TIA.

> Doug

> See my Sunday-go-to-meeting-hat at
> http://home.flash.net/~samily/DougsRockets/ConeHead4.html

> --
> samily at flash dot net

 
 
 

Aerotech F39's - Which delay is right?

Post by Jerry Irvin » Sat, 16 Mar 2002 11:54:47




Quote:
> I haven't flown any F39-12s, but based on the 6s & 9s I've flown and seen, I
> would say the NAR numbers are correct. My clubs experience has been the
> stated Aerotech numbers for the F39s are about three seconds short. YMMV

Not that I am suggesting it in this case, but for example, (ducking from
Gary) If one were to submit mess forms on these motors then one might
expect the motors are decertified or resubmitted, right?  Under current
rules.

What I suggest is on such motors where the production is done and sold,
a web page be formed that expresses all ofthe problems and workarounds
consumers had to use.

This way IF someone chooses NOT to return a clearly defective product,
they can cope.  I propose AT again suggest consumer delay modification
techniques.

Jerry

Quote:

> --
> Christopher Brian Deem       NAR 12308 TRA 2256 Level II


> > OK, I got me some 1/2 priced F39-12's from Valueland's closeout sale.  But
> I'm
> > befuddled by the double markings. Which delay is closer to the truth?
> The -12 or
> > the parenthetically included NAR certification delay of 9 seconds?

> > At the time of the NAR cert test, I'm sure the -9 was correct, but did
> Aerotech
> > ever get around to adjusting the delay to be the indicated 12? Or is it
> because
> > of a difference in when the test equipment determines motor burnout and
> starts
> > counting the delay?  Which number should I assume?

> > Three seconds delta is enough for a zipper or shred, so your good advice
> will be
> > a big help.

> > TIA.

> > Doug

> > See my Sunday-go-to-meeting-hat at
> > http://home.flash.net/~samily/DougsRockets/ConeHead4.html

> > --
> > samily at flash dot net

--
Jerry Irvine, Box 1242, Claremont, California 91711 USA

Please bring common sense back to rocketry administration.
Produce then publish.
 
 
 

Aerotech F39's - Which delay is right?

Post by Andy E » Sun, 17 Mar 2002 01:30:57


Hello Doug,

I've used the -12's in Astrocam/Maniac combos but still managed to
loose it (need a bigger field)...

I don't know if it's just me or what but it seems that Aerotech delays
have been a bit schitzoid between the NAR and AT published numbers,
especially recently.  This has been driving me nuts with the bigger
gliders.

The -12/-9's are obviously better suited for the smaller darts and
I've found globally these deploy at high speeds no matter what forcing
more attention to shock cord systems.

Just yakking...

Andy

p.s.  Going to NARCON?



Quote:

>OK, I got me some 1/2 priced F39-12's from Valueland's closeout sale.  But I'm
>befuddled by the double markings. Which delay is closer to the truth? The -12 or
>the parenthetically included NAR certification delay of 9 seconds?

>At the time of the NAR cert test, I'm sure the -9 was correct, but did Aerotech
>ever get around to adjusting the delay to be the indicated 12? Or is it because
>of a difference in when the test equipment determines motor burnout and starts
>counting the delay?  Which number should I assume?

>Three seconds delta is enough for a zipper or shred, so your good advice will be
>a big help.

>TIA.

>Doug

>See my Sunday-go-to-meeting-hat at
>http://home.flash.net/~samily/DougsRockets/ConeHead4.html

>--
>samily at flash dot net

 
 
 

Aerotech F39's - Which delay is right?

Post by EMR » Sun, 17 Mar 2002 01:46:51


I may be wrong, but I was under the impression that the 12 (9) meant
that the delay was setup to be a 12 second delay, however, the NAR
Certification Test was done on a delay of 9 seconds.  I didn't think
this meant that the NAR Test showed it to be a 12 second delay that
tested to be only 9.

Hmmmm, now I'm confused again.

- Nick

 
 
 

Aerotech F39's - Which delay is right?

Post by Sams Famil » Sun, 17 Mar 2002 01:49:20


Quote:

> Hello Doug,

> I've used the -12's in Astrocam/Maniac combos but still managed to
> loose it (need a bigger field)...

> I don't know if it's just me or what but it seems that Aerotech delays
> have been a bit schitzoid between the NAR and AT published numbers,
> especially recently.  This has been driving me nuts with the bigger
> gliders.

> The -12/-9's are obviously better suited for the smaller darts and
> I've found globally these deploy at high speeds no matter what forcing
> more attention to shock cord systems.

Thanks, Andy.  I want to fly it in my stretched Fat Boy, and Rocksim says the
optimal delay is about 9 secs.  But if it's 12, I'll be hurtin'.

Quote:
> p.s.  Going to NARCON?

I registered this morning.  Now I'm trying to get on the road to McGregor.  So
many rockets...so little time :)

Doug

--
samily at flash dot net

 
 
 

Aerotech F39's - Which delay is right?

Post by Rick Polzell » Sun, 17 Mar 2002 02:17:20


Jason?


Quote:

> OK, I got me some 1/2 priced F39-12's from Valueland's closeout sale.  But
I'm
> befuddled by the double markings. Which delay is closer to the truth?
The -12 or
> the parenthetically included NAR certification delay of 9 seconds?

> At the time of the NAR cert test, I'm sure the -9 was correct, but did
Aerotech
> ever get around to adjusting the delay to be the indicated 12? Or is it
because
> of a difference in when the test equipment determines motor burnout and
starts
> counting the delay?  Which number should I assume?

> Three seconds delta is enough for a zipper or shred, so your good advice
will be
> a big help.

> TIA.

> Doug

> See my Sunday-go-to-meeting-hat at
> http://home.flash.net/~samily/DougsRockets/ConeHead4.html

> --
> samily at flash dot net

 
 
 

Aerotech F39's - Which delay is right?

Post by Bob Kapl » Sun, 17 Mar 2002 03:43:01


Quote:

> I may be wrong, but I was under the impression that the 12 (9) meant
> that the delay was setup to be a 12 second delay, however, the NAR
> Certification Test was done on a delay of 9 seconds.  I didn't think
> this meant that the NAR Test showed it to be a 12 second delay that
> tested to be only 9.

Nope. It means that the -12s initially flunked the test for wacked delays.
By relabeling them as 9, they pass. THis is pretty standard across the 24mm
RMS, especially the BT motors. The delays run MUCH shorter than what AT
claims. About 3 seconds per motor. Why they went with the confusing double
designation instead of just changing the designations in the first place is
beyond me.

Check the NAR S&T web pages for the actual measured delays for each motor.

        Bob Kaplow      NAR # 18L       TRA # "Impeach the TRA BoD"

Kaplow Klips & Baffle:      http://www.pleimling.org/le/Phantom4000.pdf
NIRA:   http://www.nira-rocketry.org    NAR:    http://www.nar.org

        Guard with jealous attention the public liberty. Suspect every one
        who approaches that jewel. Unfortunately, nothing will preserve it
        but downright force. Whenever you give up that force, you are
        inevitably ruined. -- Patrick Henry, speech of June 5 1788

        26-October, 2001: A day that will live in infamy
        Support Freedom: http://www.indefenseoffreedom.org/

 
 
 

Aerotech F39's - Which delay is right?

Post by Jerry Irvin » Sun, 17 Mar 2002 04:38:48




Quote:


> > I may be wrong, but I was under the impression that the 12 (9) meant
> > that the delay was setup to be a 12 second delay, however, the NAR
> > Certification Test was done on a delay of 9 seconds.  I didn't think
> > this meant that the NAR Test showed it to be a 12 second delay that
> > tested to be only 9.

> Nope. It means that the -12s initially flunked the test for wacked delays.
> By relabeling them as 9, they pass. THis is pretty standard across the 24mm
> RMS, especially the BT motors. The delays run MUCH shorter than what AT
> claims. About 3 seconds per motor. Why they went with the confusing double
> designation instead of just changing the designations in the first place is
> beyond me.

I am wondering if the double designation is even legal?  I think not.

No don't call the cops.  Just have Bob (my brain wants to call him
Bobby) use new labels from now on and post the true fact to an errortech
errata page.

Jerry

--
Jerry Irvine, Box 1242, Claremont, California 91711 USA

Please bring common sense back to rocketry administration.
Produce then publish.