Launch Report: Big Daddy becomes Big Lawn Dart with Estes D-12

Launch Report: Big Daddy becomes Big Lawn Dart with Estes D-12

Post by Michael Bla » Tue, 22 Jun 1999 04:00:00



Ugh.

I've had the dubious privilage of adding another data point to the ongoing
Estes D motor ejection problem thread.  (Polite applause from the audience)
Thank you, thank you very much.

Friday I finally finished the Big Daddy I've been working on for the past 3
weeks; the first kit I've put together in 25 years.  It turned out so nice
I was a bit hesitant to fly it, but I didn't build it to hang from the
ceiling so Sunday afternoon loaded up the launch gear and headed out.

Carefully prepped the bird for flight and scored the end plug on the D12-5
just to be safe.  Launch was normal but the rocket weathervaned pretty
badly and was well on its way down when ejection occurred.  The shock cord
separated about an inch from the engine mount anchor; the nosecone drifted
down on the chute while the body tumbled in, fortunately landing in heavy
weeds with no damage.  Glad I used basswood for the fins.  I should have
taken this as a sign and gone home for the day, but nooooooo....

Lesson learned:  Use heavier shock cord than that supplied in the kit.

After mounting a longer, heavier shock cord, decided to try a D12-3.  Once
again scored the end cap.  Launch was textbook; perfectly vertical.  It
reached maybe 300 feet, gracefully arched over and headed back down.  I was
counting the seconds from engine cutoff and by the time I reached "six" it
was obvious that things would not turn out well.  No evidence of ejection
at all.  I'd never witnessed a lawn dart before and the rocket's
acceleration on descent was really very impressive.  It actually "whooshed"
during the final leg of the descent and impacted about 40 feet from the
launcher.  I was stunned and had flashbacks to the very first flight of the
first rocket I ever built, that CATOed spectacularly about 10 feet up back
in around 1972....

Here are before and  after pics:
http://schenectady.ecn.purdue.edu/~blackm/crunch.html

A post-mortem revealed no end cap remaining in the motor tube, but that may
be due to the impact.  It just appears that the ejection charge was light.
Motor date code was 4B4.

Not sure if I'll attempt a rebuild, but after this and all I've read in
r.m.r., I am *finished* with Estes D's.  Never again.  Period.  End of
discussion.  Any suggestions on 24mm composite motors?

--MB

 
 
 

Launch Report: Big Daddy becomes Big Lawn Dart with Estes D-12

Post by Bob Chmar » Tue, 22 Jun 1999 04:00:00


It was a beautiful paint job ... snif!

The AT 24-40 RMS case and reloads are a great deal.  Up to an F in a 24mm
motor.

--
Bob Chmara
NAR, HUVARS, TRA, Team1, L2, http://www.chmara.com/bt/rocketry
(remove SPAMFREE for personal replies)
The difference between the impossible and the possible
lies in a person's determination. -Tommy Lasorda

<snip>
|No evidence of ejection
|at all.
<snip>

 
 
 

Launch Report: Big Daddy becomes Big Lawn Dart with Estes D-12

Post by ter.. » Tue, 22 Jun 1999 04:00:00



   >Newsgroups: rec.models.rockets

 <SNIP>

   >A post-mortem revealed no end cap remaining in the motor tube, but
   >that may be due to the impact.  It just appears that the ejection
   >charge was light. Motor date code was 4B4.
   >Not sure if I'll attempt a rebuild, but after this and all I've
   >read in r.m.r., I am *finished* with Estes D's.  Never again.
   >Period.  End of discussion.  Any suggestions on 24mm composite
   >motors?
   >--MB

 Sorry to hear about your loss, but welcome to the Club anyway!

 Likely your "D" had insufficent ejection, You can try the Aerotech "E"
  15 engines, they get pretty pricy but man what a ride!

 Lost my First Big Daddy to power lines, the second one is still in service.

BAR = Back Again Retard, Just Ask My Wife...
Terry Bendell

 
 
 

Launch Report: Big Daddy becomes Big Lawn Dart with Estes D-12

Post by Michael Bla » Tue, 22 Jun 1999 04:00:00


Quote:


>    >Newsgroups: rec.models.rockets

>  <SNIP>

>    >A post-mortem revealed no end cap remaining in the motor tube, but
>    >that may be due to the impact.  It just appears that the ejection
>    >charge was light. Motor date code was 4B4.
>    >Not sure if I'll attempt a rebuild, but after this and all I've
>    >read in r.m.r., I am *finished* with Estes D's.  Never again.
>    >Period.  End of discussion.  Any suggestions on 24mm composite
>    >motors?
>    >--MB

>  Sorry to hear about your loss, but welcome to the Club anyway!

>  Likely your "D" had insufficent ejection, You can try the Aerotech "E"
>   15 engines, they get pretty pricy but man what a ride!

>  Lost my First Big Daddy to power lines, the second one is still in service.

> BAR = Back Again Retard, Just Ask My Wife...
> Terry Bendell

How are AeroTech 24mm motors for ejection reliability - or composites in
general compared to BP?

--MB

 
 
 

Launch Report: Big Daddy becomes Big Lawn Dart with Estes D-12

Post by Jonathan Sivie » Tue, 22 Jun 1999 04:00:00


Quote:

>How are AeroTech 24mm motors for ejection reliability - or composites in
>general compared to BP?

   I've had more problems with long delays on Aerotech motors (E15-4's that
behave like E15-12's) than I have had with BP D12's.  That's not to say
that they always fail, or even fail very often, just that out of around
25 years of flying Estes D12's I can't recall any particular failures,
but I can recall a couple of spectacular lawn darts with Aerotech E15's.
When their ejection charges do go though, they seem to have plenty of
power.

Jonathan

"Remember to always keep the pointy end up."
----------------------------------------------------------------------
|  Jonathan Sivier          |  Secretary, Central Illinois Aerospace |

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----------------------------------------------------------------------

 
 
 

Launch Report: Big Daddy becomes Big Lawn Dart with Estes D-12

Post by Hilty Information Syste » Tue, 22 Jun 1999 04:00:00



<snip>

Quote:
>A post-mortem revealed no end cap remaining in the motor tube, but that may
>be due to the impact.  It just appears that the ejection charge was light.
>Motor date code was 4B4.

Great.  Just perfect.

I've got six D12-5's in my box with... you guessed it... date codes of
4B4...

Wonder what's in my fleet that I _need_ to crash...

tah

Tod A. Hilty  NAR #72099    
Hilty Information Systems

"I'm going to put the wheels of the bus back on... just in case"
   - BlankReg, Max Headroom: 20 Minutes Into the Future

"I speak for myself _and_ my corporation!  Deal with it!"
   - blankreg

   - remove nospam.ever, and replace with apk for reply

 
 
 

Launch Report: Big Daddy becomes Big Lawn Dart with Estes D-12

Post by Steve Bloo » Tue, 22 Jun 1999 04:00:00


Quote:

>Ugh.

>I've had the dubious privilage of adding another data point to the ongoing
>Estes D motor ejection problem thread.  (Polite applause from the audience)
>Thank you, thank you very much.

Ow.

What a dandy paint job, nice work.  Also I can see you know how to work a
camera too.

As far as composites go, my choice is the Aerotech RMS motors.  Reloadables
are less costly than the single use motors and offer a nice variety of
impulse choices.  In fact, the D15-4T reload for the 24/40 motor is the same
price as the Estes D12.  Check out the aerotech site for lots of info:
http://www.aerotech-rocketry.com/

Then go to Commonwealth or Hobbylinc to buy up a few.

Good Luck,
Steve Bloom
Seattle Area Rocketeer
Skunkworks West
http://www.everett.net/users/bloomer/index.htm
For despaming:  Everett's got two "t's"

 
 
 

Launch Report: Big Daddy becomes Big Lawn Dart with Estes D-12

Post by Scott Schucke » Tue, 22 Jun 1999 04:00:00


Allow me to ad my voice to the chorus of Big Daddy / D-12 victims. Spent
my usual 3 weeks filling, sanding, and painting. Edged the fins with
basswood strips, and used a LOC style shock cord mount rather than tying
the cord to the engine mount. Alas, all the reinforcement in the world
couldn't save it from ejection charge failure.

I must say, one is glad for the NAR insurance when something goes wrong. I
had been counting on the breeze to bring it back to the launch site, but
it instead nosed into a housing development with a crash audible from 100
yards.

Fortunately, the homeowner whos roof it landed on was more amused than
upset. Inspection of the motor revealed a mostly intact clay cap, with
about a 2mm hole along the edge.

Sigh...

--Scott Schuckert

 
 
 

Launch Report: Big Daddy becomes Big Lawn Dart with Estes D-12

Post by MaxQ » Tue, 22 Jun 1999 04:00:00


A friend from our club at the NSL99 had the same problem and the lot was 4B4
!!  He lost a really neat homemade 50's "Buck Rogers" rocket on the first
flight.  The ejection diddn't even occur and the end cap was completely in
tact.  I need to have you paint my rockets - great job, and It looked great
!!  The "Rocket God's" like to eat really neat paint job rockets...  :(
Looks like the body tube could be trimmed, a coupler installed and the
rocket used again - with E's and F's this time.  :)


Quote:
> Ugh.

> I've had the dubious privilage of adding another data point to the ongoing
> Estes D motor ejection problem thread.  (Polite applause from the
audience)
> Thank you, thank you very much.

> Friday I finally finished the Big Daddy I've been working on for the past
3
> weeks; the first kit I've put together in 25 years.  It turned out so nice
> I was a bit hesitant to fly it, but I didn't build it to hang from the
> ceiling so Sunday afternoon loaded up the launch gear and headed out.

> Carefully prepped the bird for flight and scored the end plug on the D12-5
> just to be safe.  Launch was normal but the rocket weathervaned pretty
> badly and was well on its way down when ejection occurred.  The shock cord
> separated about an inch from the engine mount anchor; the nosecone drifted
> down on the chute while the body tumbled in, fortunately landing in heavy
> weeds with no damage.  Glad I used basswood for the fins.  I should have
> taken this as a sign and gone home for the day, but nooooooo....

> Lesson learned:  Use heavier shock cord than that supplied in the kit.

> After mounting a longer, heavier shock cord, decided to try a D12-3.  Once
> again scored the end cap.  Launch was textbook; perfectly vertical.  It
> reached maybe 300 feet, gracefully arched over and headed back down.  I
was
> counting the seconds from engine cutoff and by the time I reached "six" it
> was obvious that things would not turn out well.  No evidence of ejection
> at all.  I'd never witnessed a lawn dart before and the rocket's
> acceleration on descent was really very impressive.  It actually
"whooshed"
> during the final leg of the descent and impacted about 40 feet from the
> launcher.  I was stunned and had flashbacks to the very first flight of
the
> first rocket I ever built, that CATOed spectacularly about 10 feet up back
> in around 1972....

> Here are before and  after pics:
> http://schenectady.ecn.purdue.edu/~blackm/crunch.html

> A post-mortem revealed no end cap remaining in the motor tube, but that
may
> be due to the impact.  It just appears that the ejection charge was light.
> Motor date code was 4B4.

> Not sure if I'll attempt a rebuild, but after this and all I've read in
> r.m.r., I am *finished* with Estes D's.  Never again.  Period.  End of
> discussion.  Any suggestions on 24mm composite motors?

> --MB

 
 
 

Launch Report: Big Daddy becomes Big Lawn Dart with Estes D-12

Post by Tom Binfor » Tue, 22 Jun 1999 04:00:00


Quote:

> Great.  Just perfect.

> I've got six D12-5's in my box with... you guessed it... date codes of
> 4B4...

> Wonder what's in my fleet that I _need_ to crash...

A corollary of Murphy's Law states that if you put the motor in a rocket
that you don't care about, it will work. Just put it in a Saturn V and
it will fail.
Tom
 
 
 

Launch Report: Big Daddy becomes Big Lawn Dart with Estes D-12

Post by Scott McCrat » Tue, 22 Jun 1999 04:00:00


Quote:
"Bob wrote..."

>It was a beautiful paint job ... snif!

>The AT 24-40 RMS case and reloads are a great deal.  Up to an F in a 24mm
>motor.

I have a Big Daddy on the bench right now and I was wondering how I would paint
it. I think I have a good idea now! Sorry about the tragedy, it was really
beautiful.

Scott McCrate  NAR 71680


 
 
 

Launch Report: Big Daddy becomes Big Lawn Dart with Estes D-12

Post by dracomissil.. » Wed, 23 Jun 1999 04:00:00



Quote:

>    >Not sure if I'll attempt a rebuild, but after this and all I've
>    >read in r.m.r., I am *finished* with Estes D's.  Never again.
>    >Period.  End of discussion.

     That's OK.  I think Estes had the Aerotech J90 in mind when they
designed this kit anyway.

Cheers,
Joe

Sent via Deja.com http://www.deja.com/
Share what you know. Learn what you don't.

 
 
 

Launch Report: Big Daddy becomes Big Lawn Dart with Estes D-12

Post by Sean Guilda » Wed, 23 Jun 1999 04:00:00


I had the same problem with mine. Unfortunately mine lawn darted into
4' tall grass and I never found it for the post mortem.
BTW .... Great paint and pics!!!  Sean Guilday
Quote:

>Ugh.

>I've had the dubious privilage of adding another data point to the ongoing
>Estes D motor ejection problem thread.  (Polite applause from the audience)
>Thank you, thank you very much.

>Friday I finally finished the Big Daddy I've been working on for the past 3
>weeks; the first kit I've put together in 25 years.  It turned out so nice
>I was a bit hesitant to fly it, but I didn't build it to hang from the
>ceiling so Sunday afternoon loaded up the launch gear and headed out.

>Carefully prepped the bird for flight and scored the end plug on the D12-5
>just to be safe.  Launch was normal but the rocket weathervaned pretty
>badly and was well on its way down when ejection occurred.  The shock cord
>separated about an inch from the engine mount anchor; the nosecone drifted
>down on the chute while the body tumbled in, fortunately landing in heavy
>weeds with no damage.  Glad I used basswood for the fins.  I should have
>taken this as a sign and gone home for the day, but nooooooo....

>Lesson learned:  Use heavier shock cord than that supplied in the kit.

>After mounting a longer, heavier shock cord, decided to try a D12-3.  Once
>again scored the end cap.  Launch was textbook; perfectly vertical.  It
>reached maybe 300 feet, gracefully arched over and headed back down.  I was
>counting the seconds from engine cutoff and by the time I reached "six" it
>was obvious that things would not turn out well.  No evidence of ejection
>at all.  I'd never witnessed a lawn dart before and the rocket's
>acceleration on descent was really very impressive.  It actually "whooshed"
>during the final leg of the descent and impacted about 40 feet from the
>launcher.  I was stunned and had flashbacks to the very first flight of the
>first rocket I ever built, that CATOed spectacularly about 10 feet up back
>in around 1972....

>Here are before and  after pics:
>http://schenectady.ecn.purdue.edu/~blackm/crunch.html

>A post-mortem revealed no end cap remaining in the motor tube, but that may
>be due to the impact.  It just appears that the ejection charge was light.
>Motor date code was 4B4.

>Not sure if I'll attempt a rebuild, but after this and all I've read in
>r.m.r., I am *finished* with Estes D's.  Never again.  Period.  End of
>discussion.  Any suggestions on 24mm composite motors?

>--MB

 
 
 

Launch Report: Big Daddy becomes Big Lawn Dart with Estes D-12

Post by Ray Drouillar » Wed, 23 Jun 1999 04:00:00


Quote:


> > Great.  Just perfect.

> > I've got six D12-5's in my box with... you guessed it... date codes of
> > 4B4...

> > Wonder what's in my fleet that I _need_ to crash...

> A corollary of Murphy's Law states that if you put the motor in a rocket
> that you don't care about, it will work. Just put it in a Saturn V and
> it will fail.
> Tom

The device responsible for that failure is the "critical need sensor".
 
 
 

Launch Report: Big Daddy becomes Big Lawn Dart with Estes D-12

Post by Dan Schneide » Wed, 23 Jun 1999 04:00:00



Quote:


><snip>

>>A post-mortem revealed no end cap remaining in the motor tube, but that
may
>>be due to the impact.  It just appears that the ejection charge was light.
>>Motor date code was 4B4.

>Great.  Just perfect.

>I've got six D12-5's in my box with... you guessed it... date codes of
>4B4...

>Wonder what's in my fleet that I _need_ to crash...

Gee Todd, I checked my case and I have four of them also! I must've launched
the other 5 last weekend. I didn't even give it a second thought. I guess I
got lucky.

Guess what clay engine caps I scored last night!

Good luck with them!

Dan Schneider

to de-spam, remove the 3