My First Big Daddy! - My First Lawn Dart!

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ttbit

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It is with great sadness that I announce my 1st "D" engine launch since the early 80's was not so great. The launch was awesome. The flight up was great. It went higher than I expected on that D12-3. The flight back down...well... It was straight and true. I think the ground shook when it dug a nice hole with the nose cone. It made a nice boom on impact. Sounded like what the ejection charge should have sounded like.

So...I used home-made wadding (2 paper towel sheets treated with Borax) and the stock chute and cord (chute clipped on with one of those ball-bearing tackle jobs). I have a 9x9 Nomex I was going to use, but it felt heavy and I never used one before, so I thought I would start simple. I know now that it would have been fine...or in this case, no worse off. I don't know what happened. I was more worried about the nose cone falling off as it was popping up a little on it's own. I used a little masking tape to make it a little tighter, but believe me...it was not tight and still was moving up on me slightly. I have no idea what went wrong. The ejection charge happened as my wadding was wasted and I have a couple of burns on the chute. I have never experienced this. The "C" engine charges are usually violent, so I thought the D would be more so. Could it be that the charge was not enough? Heck, my son's Wizard shot back a good ways when his charge went off on a B6-4 today. The streamer came out and so did the engine, and I had that thing in tight! The next flight was a B4-4, not in as tight, and everything went normal and engine stayed put. Only difference was that I used my wadding on his first flight and estes on the second. Could my wadding have caused the issue? I can't think of anything else out of the norm from my other launches.

I know I am not using my wadding again. It passed some torch tests in the kitchen, but it burned too much in the real world. My Baby Bertha suffered some chute burn from it as well.

I want to save it. The bottom end is still perfect and nose cone just scuffed. My thoughts are to cut it down to the launch lug and splice in a new piece of 3" tubing. I will make it a little longer than stock to make a little more room for the chute. I don't think I can cut lower than that, or I won't have enough room for a coupler.

Sound OK? Suggestions on where to get the tubing?
damage2.jpg
 
I had the same thing happen to my Big Daddy last year, but it was so mangled that I never was able to figure out what went wrong.
 
It is with great sadness that I announce my 1st "D" engine launch since the early 80's was not so great. The launch was awesome. The flight up was great. It went higher than I expected on that D12-3. The flight back down...well... It was straight and true. I think the ground shook when it dug a nice hole with the nose cone. It made a nice boom on impact. Sounded like what the ejection charge should have sounded like.

So...I used home-made wadding (2 paper towel sheets treated with Borax) and the stock chute and cord (chute clipped on with one of those ball-bearing tackle jobs). I have a 9x9 Nomex I was going to use, but it felt heavy and I never used one before, so I thought I would start simple. I know now that it would have been fine...or in this case, no worse off. I don't know what happened. I was more worried about the nose cone falling off as it was popping up a little on it's own. I used a little masking tape to make it a little tighter, but believe me...it was not tight and still was moving up on me slightly. I have no idea what went wrong. The ejection charge happened as my wadding was wasted and I have a couple of burns on the chute. I have never experienced this. The "C" engine charges are usually violent, so I thought the D would be more so. Could it be that the charge was not enough? Heck, my son's Wizard shot back a good ways when his charge went off on a B6-4 today. The streamer came out and so did the engine, and I had that thing in tight! The next flight was a B4-4, not in as tight, and everything went normal and engine stayed put. Only difference was that I used my wadding on his first flight and estes on the second. Could my wadding have caused the issue? I can't think of anything else out of the norm from my other launches.

I know I am not using my wadding again. It passed some torch tests in the kitchen, but it burned too much in the real world. My Baby Bertha suffered some chute burn from it as well.

I want to save it. The bottom end is still perfect and nose cone just scuffed. My thoughts are to cut it down to the launch lug and splice in a new piece of 3" tubing. I will make it a little longer than stock to make a little more room for the chute. I don't think I can cut lower than that, or I won't have enough room for a coupler.

Sound OK? Suggestions on where to get the tubing?
View attachment 178703


Too bad about the crash --- you did a good job on the finish and it looked great.

I had mine crash too when I over stuffed the recovery and it was all jammed in a bit too tight. I used a 12x12 nomex blanket and a nylon chute and it all took up too much room (I had never used this kind of setup and did not really know how to do it). The ejection charge actually burned through the blanket and singed the nylon chute! Maybe if I had used a 9x9 nomex and thin mill chute...

Prior to that disastrous launch, I had flown it on stock recovery gear using regular wadding and dog barf, and it had recovered successfully each time, but the plastic chute was getting burns over time. That's why I had upgraded.

I spoke to another person at a club launch who had a slightly banged up Daddy. He said his had crashed a time or two on the stock gear when the ejection charge had not fully ejected the chute. He said someone had told him that the shoulder of the nose cone is too long and the angle at the bottom of the shoulder allows the NC to slide out partway, until the short side of the shoulder clears the BT, and then the gases can all vent out without pushing the NC all the way out. I'm not sure if that is correct or not, but he cut off the bottom half of the shoulder and said his has not crashed since.

I think the main problem is the compartment is not very big. It doesn't leave very much room for wadding, and it leads to cramming the recovery in too tight and very close to the ejection charge. This can cause two kinds of problems. The charge can blow through the minimal wadding, burning the chute. And the tightly packed recovery can jam in the tube, and fail to fully eject.

I think if you rebuild the rocket with another 4" to 6" of body tube, the added length will cure most of the problems. You'll have room for more wadding and won't have to pack the chute too tightly. Estes sells the correct 3" tube and the correct coupler under PSII parts on their website --- it's the same tube used for the Leviathan.

Good luck!
 
I believe that you can get Estes 3" tubes from Estes, or Balsa Machining, ask with BM first to see if they have the right one.

I would suggest that it is probably easier and cheaper to get a new Big Daddy. Yup, I lawn darted a couple.
 
I have seen a few and have heard of others who have experienced a less than dynamic ejection charge on D12 motors. File a M.E.S.S. report and contact Estes. If they agree that this was a motor failure, they not only send you a pack of replacement motors, but will send you a replacement for the rocket that it destroyed! Estes has excellent customer and warranty support!


Jerome :)
 
Thanks all. Before I got on here again this evening, I thought about maybe the gases passing through somehow. Check out this picture. Funny how it collected there. I think Thirsty is onto something here... I wonder if the nose was tighter, if it would have blown out better also. It being loose, it just helped it to open up and burp...maybe...

nose.jpg

Thanks for the info on the tube also. I was able to locate it through Estes.

I probably spent too much time finishing this rocket and got too attached. hahaha It was my first papered fin job too. I had dreams of over-powering it. I know though...part of it. I got hooked on that thrust though. Been working with openrocket trying to design a simple bt80 rocket for a D12 tonight. Should have been in bed 3 hours ago. I am amazed at how .1 inch of a fin change can double the apogee. I guess that is another thread...
 
I have seen a few and have heard of others who have experienced a less than dynamic ejection charge on D12 motors. File a M.E.S.S. report and contact Estes. If they agree that this was a motor failure, they not only send you a pack of replacement motors, but will send you a replacement for the rocket that it destroyed! Estes has excellent customer and warranty support!


Jerome :)

Will call them tomorrow. Thank you.
 
Wrap it with clear shipping tape in a spiral and launch again. I would also cover the hole in the bottom of the nose cone, I use foil tape, but masking tape will work also.



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... He said someone had told him that the shoulder of the nose cone is too long and the angle at the bottom of the shoulder allows the NC to slide out partway, until the short side of the shoulder clears the BT, and then the gases can all vent out without pushing the NC all the way out. ...

I think this is entirely possible. I had a BD go on a cruise missile trajectory. It landed on it's side rather than lawndarting and nose cone still seated in the tube with about half of the shoulder still in. The same explanation was offered by my rocket buddies. The combination of a long, angled shoulder and a tight fit makes this a possibility.

Wrap it with clear shipping tape in a spiral and launch again. I would also cover the hole in the bottom of the nose cone, I use foil tape, but masking tape will work also.

100% agree. Your first D launch vehicle since the 80's must fly again. Major surgery is not needed IMHO. It's just a flesh wound. :wink:
 
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I think this is entirely possible. I had a BD go on a cruise missile trajectory. It landed on it's side rather than lawndarting and nose cone still seated in the tube with about half of the shoulder still in. The same explanation was offered by my rocket buddies. The combination of a long, angled shoulder and a tight fit makes this a possibility.



100% agree. Your first D launch vehicle since the 80's must fly again. Major surgery is not needed IMHO. It's just a flesh wound. :wink:

Well said Black Knight.
 
Looks like you had a nice looking Big Daddy there... Sorry about the lawn dart.

If you are set on cutting away the damaged area (and don't mind having an extra seam), you could consider making your BD a zipperless design.
 
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Seeing how this has happened to more than one member, I notified Estes' Product Safety Compliance Representative (Mary Roberts), and advised her of this thread. She's looking into it.

Has anybody had a problem with the same nose cone on a Leviathan?
 
Well said Black Knight.

Ha, exactly! Sometimes you want to make a damaged rocket flyable but preserve the battle scars for sentimental reasons.

Seeing how this has happened to more than one member, I notified Estes' Product Safety Compliance Representative (Mary Roberts), and advised her of this thread. She's looking into it.

Has anybody had a problem with the same nose cone on a Leviathan?

Not a big deal to me, just make sure that the shoulder can move freely along the entire length. One sheet of wading across the forward CR, a little dog barf, the z-folded stock chute (sometimes use 16 or 18 inch on windier days) wrapped with 1 or 2 sheets of wadding. Sand the shoulder and forward body tube as needed after each flight. Much love for the BD !
 
OK. I used some glue on the tube as its integrity was really compromised and will wrap with tape when it is all dry. I applied some ca on the tube edge to stiffen it up a slight bit. Will sand the bottom of the cone to make sure it is not too tight, and the standard shoulder area is pretty loose already. Strange again though, as I thought everything was TOO loose. If you only knew how much tighter I packed some of those little rockets. Those little ones can be tough as all of you know!

If I decide to cut the bottom part of the shoulder off, what should I glue to the bottom of the cone to seal it back up and what glue do you all suggest? I am fine with paper and wood, but plastic is always iffy to me. That will leave a big opening, and then I will need to mount the shock-cord to it in some way.

I will at least plug the hole and I also emailed Estes.
 
Looks like you had a nice looking Big Daddy there... Sorry about the lawn dart.

If you are set on cutting away the damaged area (and don't mind having an extra seam), you could consider making your BD a zipperless design.

Interesting. A seam on this would be the least of my problems. hhahahaha. I think Black Night and Lowpuller are right. Worst case, I get to practice nomex loading. I will see if I can get this thing straight enough to launch again.
 
So I figured that I had this thing ready to fly again.

To test, I decided to throw some air from my compressor to it using a spent engine and pointing an air nozzle at it. I get a fairly good seal from it. At 20-80 psi, the nose cone stops at the bevel. Tightening the fit to about 5 times tighter than I had at launch helps about 1/16th of an inch, so that's not it. My other rockets, the nose cone shoots out and yanks the shock cord. I am pretty sure that I should modify this nose cone. There is nothing pulling or pushing the rest of the guts out, so I believe I would be looking at another lawn dart experience. At least if the nose cone just falls out, there is a chance it will pull the chute with it. Not a chance for the nomex. I would not trust using the nomex I have, as although it is not tight, it won't fall out on its own. It does not budge from the air, so the nose cone has to yank the chute out of it. I guess I never really thought much about how the ejection happens. Where the air goes and what causes everything to come out.

Covering the hole in the nose cone does not change the result. Using just wadding and the chute does not change anything. Having no chute and just the cone, no change. The problem is, if it stops at that beveled section, the nose cone can get crooked and get jammed on the tube.

Maybe my air simulation is not really a good test...
 
I would cover the hole in the nose cone to reduce the volume of rocket that needs to be pressurized by the ejection charge.

Just as an FYI my Leviathan lawn darted on the first launch.

ImageUploadedByRocketry Forum1406261045.073243.jpg

My nose cone was tight in NC and even tighter at the launch in SC, which was 10 degrees or more hotter. I sanded the nose cone at the field until I felt it was loose enough, but apparently not or maybe there is another issue.


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So I figured that I had this thing ready to fly again.

To test, I decided to throw some air from my compressor to it using a spent engine and pointing an air nozzle at it. I get a fairly good seal from it. At 20-80 psi, the nose cone stops at the bevel. Tightening the fit to about 5 times tighter than I had at launch helps about 1/16th of an inch, so that's not it. My other rockets, the nose cone shoots out and yanks the shock cord. I am pretty sure that I should modify this nose cone. There is nothing pulling or pushing the rest of the guts out, so I believe I would be looking at another lawn dart experience. At least if the nose cone just falls out, there is a chance it will pull the chute with it. Not a chance for the nomex. I would not trust using the nomex I have, as although it is not tight, it won't fall out on its own. It does not budge from the air, so the nose cone has to yank the chute out of it. I guess I never really thought much about how the ejection happens. Where the air goes and what causes everything to come out.

Covering the hole in the nose cone does not change the result. Using just wadding and the chute does not change anything. Having no chute and just the cone, no change. The problem is, if it stops at that beveled section, the nose cone can get crooked and get jammed on the tube.

Maybe my air simulation is not really a good test...

I would cover the hole in the nose cone to reduce the volume of rocket that needs to be pressurized by the ejection charge.

Just as an FYI my Leviathan lawn darted on the first launch.

View attachment 178806

My nose cone was tight in NC and even tighter at the launch in SC, which was 10 degrees or more hotter. I sanded the nose cone at the field until I felt it was loose enough, but apparently not or maybe there is another issue.

That tears it... I'm modifying my rocket's nosecones. I'm not about to ruin a rocket because the N/C vents the ejection gasses.

I think I'll fill the bevel with foam, then sand it down.

Sorry for your losses...
Jim
 
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Here is the nose cone!

ImageUploadedByRocketry Forum1406262025.765369.jpg

It was seriously stuck in the ground, very glad it didn't hit anyone or their car as it landed kinda close to the flight line.


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Sorry about the lawn dart, that was a very nice paint job.

On my Big Daddy I enlarged the hole in the bottom of the nose cone, and then extended the motor mount so that it went inside the nose cone. It eliminates the need for wadding, and It has blown the nose cone off every time.

Mike
 
I would cover the hole in the nose cone to reduce the volume of rocket that needs to be pressurized by the ejection charge.

Just as an FYI my Leviathan lawn darted on the first launch.

View attachment 178806

My nose cone was tight in NC and even tighter at the launch in SC, which was 10 degrees or more hotter. I sanded the nose cone at the field until I felt it was loose enough, but apparently not or maybe there is another issue.


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OK...Now I know why you thought mine was so minor. WOW. Sorry about that.
 
Sorry about the lawn dart, that was a very nice paint job.

On my Big Daddy I enlarged the hole in the bottom of the nose cone, and then extended the motor mount so that it went inside the nose cone. It eliminates the need for wadding, and It has blown the nose cone off every time.

Mike


I have tube here. I am going to try this. That containing of the charge should send the nose cone into orbit. I saw this mod somewhere before and it completely slipped my mind. Too bad I built mine stock. I will have to be a little more creative with adding the tube. Glad I didn't start surgery yet!
 
I have built BD and Leviathan. They are very similar rockets. The NC and the slotted BT are the exact same components. That means if there is a BD NC issue, you will also see it on Leviathans. I cut off the bottom of both NCs up to the taper. It wasn't to address the venting issue you guys are discussing, but it would solve that issue.
 
So...I added the tube. I was able to use a centering ring I had to slide it onto the existing tube (all 1/8" sticking out) and then added another CR that I made to go out to the body tube. Sucker is not going anywhere now. CA'd the top of the tube and then touched it 5 minutes later and almost glued my fingers together. :) Glue is dry now and nose cone cut, so I did the same test with the air compressor. I had to laugh....nose cone came out the exact same distance, or a tad less. hahahaha what? Let's just say maybe there is a limitation of air due to using the D engine nozzle. There is just no way this could be an issue. I may try to launch this way. The other option is to cut the rest of the nose bottom, I guess.
cone1.jpgtubemodify1.jpg
 
I'd glue some hard foam (polystyrene or similar) to the bevel and then sand it until it slides inside the body tube. Then cut away what is needed to attach the shock cord.

You may also wan't to remove the stuffer tube you just installed, and and seal the hole you widened in the n/c.

Just my :2:
Jim
 
So...I added the tube. I was able to use a centering ring I had to slide it onto the existing tube (all 1/8" sticking out) and then added another CR that I made to go out to the body tube. Sucker is not going anywhere now. CA'd the top of the tube and then touched it 5 minutes later and almost glued my fingers together. :) Glue is dry now and nose cone cut, so I did the same test with the air compressor. I had to laugh....nose cone came out the exact same distance, or a tad less. hahahaha what? Let's just say maybe there is a limitation of air due to using the D engine nozzle. There is just no way this could be an issue. I may try to launch this way. The other option is to cut the rest of the nose bottom, I guess.
View attachment 178865View attachment 178866

You could also put some epoxy in the nose cone for a little more protection. I have stuffed the extended motor tube with dog barf, and that worked as well. I believe that you saw this modification here: https://www.rocketreviews.com/estes-big-daddy3-mike-goss.html That would be my Big daddy:D
 
I'd glue some hard foam (polystyrene or similar) to the bevel and then sand it until it slides inside the body tube. Then cut away what is needed to attach the shock cord.

You may also wan't to remove the stuffer tube you just installed, and and seal the hole you widened in the n/c.

Just my :2:
Jim

Well, if I try that, I will have to re-mount the shock cord also. This was before I learned of kevlar and ways to attach. What do you use to glue hard foam?

Why the heck is this a problem, if I just greatly reduced my air mass and directed it right at the cone? Granted, there is going to be escaped air and such, but... Hey...I am no engineer. :)
 
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