Lawn Dart / Core Sample Gallery

[cwbullet]

I would like to see some photos of varios lawn darts. Let us see your core samples and lawn darts. I have a few and will post some tonight.

 

[bill2654]

Blue tube was not hurt and got the NC back too. Ready to go again.

 

[Micromeister]

Why should we promote Failures. Dawn darts and Core samples are nothing more then mistakes made by those flying the rocket.

these are things to be avoided not promoted or even laughed at. They are a safety issue that should not be taken lightly. Stripped chutes, failing to install the ejection charge, change the battery or whatever the mode...they shouldn't be condoned. CATO's are bad enough.

 

[cwbullet]

Hmm, I am not promoting them. They occur and will continue to do so. I just wanted examples for a failures slide show - what not to do show.

 

[UPscaler]

I could quote Forrest Gump('s conversation with the bumpersticker guy) but I wont...instead, I'll say Accidents happen, and they will continue to do so...


here is the best one I've got. The rocket is mine, OSD. It's estes BT-60 tubing wrapped in fiberglass with G10 fins, only about 1/2 inch had to be cut off but it totally messed up my paint job...now the lines don't match on the body tube and nosecone. Feel free to use it for your slide show...


Braden

 

[Scotty Dog]

Why should we promote Failures. Dawn darts and Core samples are nothing more then mistakes made by those flying the rocket.

these are things to be avoided not promoted or even laughed at. They are a safety issue that should not be taken lightly. Stripped chutes, failing to install the ejection charge, change the battery or whatever the mode...they shouldn't be condoned. CATO's are bad enough.

Guess it depends on how ya see it. I look at it as a stark reminder of the horrors of making said mistakes. And Im sure there has been lawn darts due to equipment failers rather than owner operator mistakes.Same goes for CATOs

 

[cwbullet]

This a a photo of a core sample. This is an example of too small of ejection charge. The ejection charge was too small. It failed to push out the recovery and came in ballistic.

 

[cwbullet]

Another core sample. This rocket s one of our more seasoned members. He has lots of experience. The chute failed to fully inflate.

 

[rstaff3]

I have no idea when or where I found these but thought they belonged

 

[Ethan]

4" Min Dia. N. O-ring failure 0.2 seconds into burn vented propellant gases into drogue bay and dumped the upper airframe along with the closure. Propellant remained lit and the Case + fincan continued in ramjet mode before core sampling a Km or so downrange

 

[adrian]

Lawn dart.

The photo is poor because this was 1998 and I didn't have as nice a camera as I have now. The landing looks worse than it was because the ground was soft; the rocket took no damage and is still able to fly today.

 

[Brent]

Another core sample. This rocket s one of our more seasoned members. He has lots of experience. The chute failed to fully inflate.

That was my Arcas. The core sample was caused by a failure in a glue joint on the forward centering ring. It was a pain in the rear to dig out of the sod. When it failed, it probably had 25 flights on it, mostly on K550s. She is all pretty again now. The only real damage was paint, decals and my pride.

 

[dixontj93060]

I can participate... My Aerotech Mirage with 6 feet of it underground.

In an effort to make this a productive post, here was the learning from this flight:

1. Triple 7 black powder substitute provides challenges in achieving enough containment when using plastic centrifuge containers.
2. After this event, and subsequently more extensive ground testing with mixed results, I no longer use Triple 7 with centrifuge containers.
   
   
   
   
   

 

[Pem Tech]

While I agree with you that these incidents are safety issues and should not be taken lightly, I disagree with your presumption that they are "nothing more then mistakes made by those flying the rocket."
Sure, we make mistakes, but sometimes things go wrong that are not the fault of the flyer.
Upscaler nailed it, accidents happen and we shouldn't pretend they don't happen. We can learn from the experience of others as not to repeat the same failings.

Saying that, I would like to see the posters include the circumstances of the events, causes and any advice that can be offered.

Why should we promote Failures. Dawn darts and Core samples are nothing more then mistakes made by those flying the rocket.

these are things to be avoided not promoted or even laughed at. They are a safety issue that should not be taken lightly. Stripped chutes, failing to install the ejection charge, change the battery or whatever the mode...they shouldn't be condoned. CATO's are bad enough.

 

[JoeLaunchman]

Here's a 2-stager for your gallery. The booster is a recycled Beta bottom stage. In this case the A10-0T failed to ignite the A3-4T.

 

[Micromeister]

While I agree with you that these incidents are safety issues and should not be taken lightly, I disagree with your presumption that they are "nothing more then mistakes made by those flying the rocket."
Sure, we make mistakes, but sometimes things go wrong that are not the fault of the flyer.
Upscaler nailed it, accidents happen and we shouldn't pretend they don't happen. We can learn from the experience of others as not to repeat the same failings.

Saying that, I would like to see the posters include the circumstances of the events, causes and any advice that can be offered.

The Thread author made no mention of purpose for this gallery. As such it could easily be views as just another fun thing to try. Hey; even I have a Lawn Dart Model...It recoveries however by Chute..but still sticks in the ground similar to Adrian's...which is a very NIFTY looking model by the way So is not a model I usually list, show or fly with others around. WHY...Cause I do not want to give the wrong impression to other who might see it.

That's the Problem with the premise, and the Forrest gump quote would fit quite well.
We don't learn from our mistakes....we keep right on doing the SAME exact "S----d" things. Most (Not All) but MOST Equipment failures can still be traced back to something NOT done, Chosen, packed, prepped or prepared correctly. Will they continue of course, but "Lawn Darts & Core Samples" as a practice is not something to be, encouraged, condoned or laughed at by listing in a Gallery Unless as you mention IT IS done as A Gallery of SHAME.
CW Most Failure and Mishap slide shows, videos and others forms generally are not viewed as teaching aids but funny side shows....One of our club members has a 1/2 hour long montage of NASA "They Blew UP real Good" mishaps, failed test launches and "training aid films" that turn my stomach every time it's shown. Why because while it showns that Designing and testing Rockets can be a tough and dangerous job...more in the room are laughing at the mayhem then learning one darn thing from what they are seeing...ditto looking at lawn dart and core sampled models Unless there is a very clear discussion of WHY it failed.

 

[cwbullet]

The Thread author made no mention of purpose for this gallery. As such it could easily be views as just another fun thing to try. That's the Problem with the premise, and the Forrest gump quote would fit quite well.

I should have explained more. I did not think it was needed. I am absolutely not trying to encourage anyone to make a mistake. I am very safe and use to be idealistic. I thought I would never make one. After several crashed rockets, I now think differently. Mistakes happen, but I will learn from each and try lessen them in the future.

I recently had 2 rockets destroy a fellow rocketeer's tent on 2 sucessive days. 1 landed with chute open. The other landed with the chute collapsed. The chute collaped when the chute protector tipped and went up the shroud lines. No one was hurt and it was a learning experience.

I also understand how they turn your stomach. I guess I just look at things differently.

 

[sebaney]

I saw this thread and now I want to go make a mistake. I can't seem to control myself.... must...... cato....... need......lawndart......can't ....stop....:y:

 

[Pem Tech]

I saw this thread and now I want to go make a mistake. I can't seem to control myself.... must...... cato....... need......lawndart......can't ....stop....:y:

:lol:

 

[cwbullet]

That was my Arcas. The core sample was caused by a failure in a glue joint on the forward centering ring. It was a pain in the rear to dig out of the sod. When it failed, it probably had 25 flights on it, mostly on K550s. She is all pretty again now. The only real damage was paint, decals and my pride.

I ddi not not know the exact cause, but I did not want to dime you out by name.

 

[MarkII]

Lawn darts are clearly not results that anyone wants to get. Even leaving aside the safety issue, we all put too much blood, sweat, tears and treasure into our rocket builds to want them to end up that way. And no one but no one wants to be responsible for injuring someone or causing damage to someone's property. These photos are hardly sources of pride, and no one is celebrating these incidents. I see the thread as being a version of the "what is your most embarrassing flight?" type of discussion, and it represents flights that are, to borrow a Pink Book term, "self-penalizing." The sharing of photos is not going to lead to more ballistic return incidents.

This isn't a victory stand; it's a confessional. And we all know what confession is good for.

 

[cwbullet]

"self-penalizing." The sharing of photos is not going to lead to more ballistic return incidents.

I absolutely agree with with. My own guilt penalized me more than the loss of an rocket. The embarrassment of mistakes is enough.

This isn't a victory stand; it's a confessional. And we all know what confession is good for.

Bless me father for I have sinned. I confess for having left out a parachute and ejection charge and for forgetting to hook up a shock cord. I hope to have the memory and though to not have it happen again.

All kidding aside, I hope this never happens again, but I doubt this thread will increase them.

 

[Eric1]

Chuck, I see no harm in this thread. You are not promoting anything. I see no reason not to post the aftermath shots.

Peace

Eric Foster

 

[qquake2k]

Don't let the disparaging comments of ONE poster dissuade any of you. I love this thread. It's human nature to have a morbid fascination with failure. The "train wreck" mentality, if you will. Nobody was hurt in any of these incidents, and we are not glorifying failure. If anything, these should serve as a reminder that bad things can happen, and make us think more carefully about our preparations for flight. These examples might even PREVENT similar catastrophes. Let's face it, ours is a potentially dangerous hobby. No getting around that. But there are other dangerous hobbies, too. I once saw a corner marshal get rammed in the ankle by a 1/8 scale gas powered RC buggy at full speed. Stuff happens.

Now, on to my failure. Since I've been a BAR (about two years now), I've been fortunate to only have one lawn dart. It was my 9ft tall "Halfway There". I have no idea what caused it. I know the ejection charge went off, there was BP residue in the stuffer tube. Not enough BP? Too much volume in the stuffer/body tube? Too much friction at the separation joint? Who knows? Yes, I was saddened watching it auger in on its maiden voyage. But it was exciting to watch, nonetheless!

 

[eggplant]

We didn't get any pictures, but the video tells all.
[YOUTUBE]khrAkkzFnsU[/YOUTUBE]

 

[Blackfly]

99.99% lawn dart......

After some very serious investigation, this "ballistic recovery" was the result of the following:

-Over estimated delay by 2 seconds.
-Pad whip caused an altitude reduction of roughly 500 feet, as compared to previous launches of the same rocket, on the same motor, in the same conditions. Look at the 2nd photo; it launched from the pad on the right!
-Motor ejection delay was longer than MFG'rs specs by 3.5 seconds.

The recovery system worked perfectly, except that it was deployed at about 120' agl. By this point the rocket was coming in at over 300fps. In the 4th photo you can see the ejection charge firing.

In the 5th photo, the booster section has separated and the main is on its way out; unfortunately, the green spot in the lower right corner is actually the top leaves of a tree.

 

[Blackfly]

99.99% continued........

First photo; main compartment slams in to ground.. The big white booster, not far behind and still going 300fps, is visible in the frame, 1:00 position.

Second photo; booster slams into main compartment just behind the camera.. You can see the deformation of the tube, versus the first photo.

Third photo.... a slow death.. Audio continues to roll, incredibly, picking up the sound of the next launch and the PA announcement, over 1700 feet away.

Fourth; as found. Shovel came in handy here; you can't even see the main.

After an epic 3 hour recovery mission, all the components are laid out.

Lessons learned:

Dual deploy or at least a redundant system for all of my future HPR launches.
even 1-2 degrees of play in an HPR tower is enough to cause significant pad whip. (I'm already building a new tower to replace the clubs existing ones.)
Motor delays are reliable, but not perfect.

 

[MarkII]

Bless me father for I have sinned. I confess for having less out a parachute and ejection charge and for forgetting to hook up a shock cord. I hope to have the memory and though to not have it happen again.

For your penance you must recite six Hail Marys during each of your next two bonus delays. Your sins are forgiven. Go forth, my son, and sin no more.

 

[atxcple]

this is my Vaughn Brothers wild thing 8 motor cluster. it is a central 38mm with 7 29mm motors around it in a circular design. 7 fins, each mounted in between the 29mm motor tubes. Motor ejection off the central motor.
FLIGHT BRIEF:
flight was looking good right after ignition, then as it cleared the rod things started going wrong in a hurry. did 2 1/2 rotations before powering in.

the motors chosen were a central PRO38 I285 ( more than enough to fly this rocket on its own) and 7 AT G35's.

View attachment 54100





lessons learned the hard way:

1. motor choice is critical in clusters. (pro38's come up to preasure a whole lot faster than AT motors) use motors that come up to preasure in the same amount of time. i now use all Pro38 and pro29 motors when flying the full stack.

2. use longer igniter leads to give the igniter a better chance inside the motor. i now use 5 ft leads to give the rocket a little travel time.

3. carefully select your igniters. i test all igniters with a multimeter for ohms and match them to within 0.01 of each other when ever possible.

4. dont use motor ejection for main deployment events. upgraded to electronics to hopefully get the laundry out if it is a off axis flight.

 

[bradycros]

....One of our club members has a 1/2 hour long montage of NASA "They Blew UP real Good" mishaps, failed test launches and "training aid films" that turn my stomach every time it's shown.

Why would you think anyone, anywhere, at anytime would be conserned about you blowing the contents of your stomach?