Why it does not ignite ?

[THEONE]

Ok i have made in the past some G impulse engines with PVC and cement, and i most of times add at the end a longer grain than the normal without a core (like a delay grain) to produce smoke for tracking but most of times it seems that it does not ignite...

[dagabu]

Ok i have made in the past some G impulse engines with PVC and cement, and i most of times add at the end a longer grain than the normal without a core (like a delay grain) to produce smoke for tracking but most of times it seems that it does not ignite...

 

Criminy!

 

-dag

[THEONE]

What do you mean

[dagabu]

Criminy!

As in, "Criminy! I can't believe that this guy is still making PVC rockets with cement nozzles!

-dag

[bob]

you mean that it might blow out and hit him in the head?

Thanks

[dagabu]

No, that it will CATO and hurt someone else. I told him before that it was a poor decision to use PVC and cement, Criminy!

-dag

[bob]

why will that make it cato?

 

bob

[dagabu]

why will that make it cato?

 

bob

 

Sorry, really tired, need to clarify.

 

Theone uses items like PVC to make motors. Theone CATOs lots of motors (who doesn't?). I told him before that I have no interest in helping him make or troubleshoot PVC motors or cement nozzles.

 

Theone still posts these dangerous rocket motors here and I simply commented, "Criminy!"

As in, "Criminy! Stop making these things and roll some paper tubes with clay nozzles for goodness sake."

-dag

[THEONE]

After i have learn from my mistakes i haven't got catoes any more

Also i have told this before, if the motor it will catoed it will not broke the pipe (like a pipe bomb) but the cement will go out, only like that

[Blackthumb]

Criminy...criminy!

 

Stay with paper and clay as Dag suggests.....much safer.

[bob]

ok I under stand now I thought he was using it in the fuel or somthing not as the casing thanks for explaning that to me dag

well now that I under stand I have to say the same thing criminy

rolling paper tubes really isn't that hard and then unless it catos in your hand I don't think you have any thing to worry about

I do under stand what your saying about the plug coming out before the pipe would explode but there still is a chance it depends one how thick it is but then you start having wight problems

why may I ask are you not using paper cause although I have not checked I would think that paper would be cheaper then pvc and then of course you can roll them so they cost a cent each

IMO of course

[dagabu]

After i have learn from my mistakes i haven't got catoes any more

Also i have told this before, if the motor it will catoed it will not broke the pipe (like a pipe bomb) but the cement will go out, only like that

 

...but the cement will go out, only like that... Like a bullet, yes I understand the concept. I used to shoot cement filled soda cans out of well casing. Same effect just larger.

 

-dag

[ExplosiveCoek]

You can simply not roll your own tubes when you're making decent rockets, unless you're making it a helluva thick casing. Although "casing" would then be the wrong word here, I think "glue with some paper added" would suit the explanation better for home made tubes. They simply can not match the quality of industrial made tubes.

 

I've been using PVC tubes for a long time now, never had one fail on me. Saying things like a rocket should CATO every once in a while is total crap, and only is because the creator of the rocket failed to keep his fuel/preparation method the same. Putting a header on top of a dangerous rocket is just as dangerous, or maybe even more dangerous then the slight possibility that PVC might shatter when it might CATO. And I've seen quite some failing rockets from Mr. Dag

 

Please stop whining about the PVC and go make some fireworks. However, DO NOT include cement plugs in them, they'll hit you hard like Dag already told you, use clay instead. Works better, easier and cleaner too. They will still give you a nice headache though once they're getting launched in the wrong direction. Probably you don't want to be using plugs any more at all, at least that's what I'm doing.

 

Furthermore, THEONE, I don't really understand the question. What kind of rockets are you making, and what is the precise problem? Have you tried burning one on the ground (so upside down, not letting it fly)?

 

 

End of rant. Have a nice day.

[bob]

You can simply not roll your own tubes when you're making decent rockets, unless you're making it a helluva thick casing. Although "casing" would then be the wrong word here, I think "glue with some paper added" would suit the explanation better for home made tubes. They simply can not match the quality of industrial made tubes.

 

I've been using PVC tubes for a long time now, never had one fail on me. Saying things like a rocket should CATO every once in a while is total crap, and only is because the creator of the rocket failed to keep his fuel/preparation method the same. Putting a header on top of a dangerous rocket is just as dangerous, or maybe even more dangerous then the slight possibility that PVC might shatter when it might CATO. And I've seen quite some failing rockets from Mr. Dag

 

Please stop whining about the PVC and go make some fireworks. However, DO NOT include cement plugs in them, they'll hit you hard like Dag already told you, use clay instead. Works better, easier and cleaner too. They will still give you a nice headache though once they're getting launched in the wrong direction. Probably you don't want to be using plugs any more at all, at least that's what I'm doing.

 

Furthermore, THEONE, I don't really understand the question. What kind of rockets are you making, and what is the precise problem? Have you tried burning one on the ground (so upside down, not letting it fly)?

 

 

End of rant. Have a nice day.

I make rockets with my hand rolled casings and although I have got catos it has had nothing to do with the casing

I know I'm new to this but I know a lot of people that are masters (although I have never met these people face to face I have been on forums and that they are mods on and have been for years so I don't think they make every thing up about rockets) when it comes to rockets and quite a few roll there one tubes for rockets

my guess would be that you have tried rolling your on in the past but had no luck

and trust me my first 15 tubes didn't work but then I started doing some things diffrent and now they are strong very strong

I'm sure if you put in the time you could make some really nice tubes your self

bob

Edited June 27, 2012 by bob

[dagabu]

You can simply not roll your own tubes when you're making decent rockets, unless you're making it a helluva thick casing. Although "casing" would then be the wrong word here, I think "glue with some paper added" would suit the explanation better for home made tubes. They simply can not match the quality of industrial made tubes.

 

I've been using PVC tubes for a long time now, never had one fail on me. Saying things like a rocket should CATO every once in a while is total crap, and only is because the creator of the rocket failed to keep his fuel/preparation method the same. Putting a header on top of a dangerous rocket is just as dangerous, or maybe even more dangerous then the slight possibility that PVC might shatter when it might CATO. And I've seen quite some failing rockets from Mr. Dag

 

Please stop whining about the PVC and go make some fireworks. However, DO NOT include cement plugs in them, they'll hit you hard like Dag already told you, use clay instead. Works better, easier and cleaner too. They will still give you a nice headache though once they're getting launched in the wrong direction. Probably you don't want to be using plugs any more at all, at least that's what I'm doing.

 

Furthermore, THEONE, I don't really understand the question. What kind of rockets are you making, and what is the precise problem? Have you tried burning one on the ground (so upside down, not letting it fly)?

 

 

End of rant. Have a nice day.

 

I hesitate to answer your lashing EC but I think you have taken some liberties with your statements that are misleading or false. The first is the use of PVC pipe. There is no whining going on here just a simple statement that after pulling fragments out of my own skin years ago, others need to know what danger PVC pipe has when loaded with rocket fuels.

 

I can hardly agree with you about your statement, " rocket should CATO every once in a while is total crap". I don't recall saying that, what I did say is, "who hasn't?" I still CATO rockets, I am still searching for the red line and anybody looking for the red line will push beyond it once in a while. I post videos of my failures as well as my successes, it reminds me that I am no expert and that I am always in the place to learn more.

 

I have now flown well over 1000 rockets with no CATO, I launch around 30 of them each time I shoot and do so several times a year covered by a licence and permit. I still push the limit now and again and I do not apologize for that.

 

Knowing that you use PVC habitually and have not been able to roll a suitable tube that will work for you like a commercial tube is too bad. It just shows that you are stuck using objectionable materials with poorly powered fuel. Such is the goal of mediocrity, congratulations.

 

I roll 5/8" ID tubes all the time, flights of a dozen or so are common and I have even used whistle (nozzleless and in end burners) using these tubes with only one pop on me last weekend because I used too short of a bulkhead (experimenting) and it blew under pressure. I lift single 1" crossettes to around 200' for good viewing, they are very reliable.

 

Finally, your statement of, "Putting a header on top of a dangerous rocket is just as dangerous, or maybe even more dangerous then the slight possibility that PVC might shatter when it might CATO" is irresponsible at the best. PVC pipe WILL shatter if the motor CATOs. If the plug or nozzle is ejected, that is not a CATO, that is a failure, nothing more. C= catastrophic.

 

I do appreciate your lashing, the good people here now have even a better understanding of the fallacies you spread in vitriol v.s. a simple conversation. Please feel free to vomit your rebuttal, I am ready for a good row if you are.

 

-dag

Edited June 28, 2012 by dagabu

[bob]

+1

bob

[dagabu]

You can simply not roll your own tubes when you're making decent rockets, unless you're making it a helluva thick casing. Although "casing" would then be the wrong word here, I think "glue with some paper added" would suit the explanation better for home made tubes. They simply can not match the quality of industrial made tubes.

 

Please let me add one more thing, this statement is certainly as false as Cher's eyelashes. There are many very good if not the best scratch made rocketeers that produce motor casings by hand the far exceed even the gold standard, NEPT in burst strength. We have a few here that have done so and displayed their rockets and wonderful shells right here at APC.

 

This was no commercial tube and certainly not a glue plus a little paper...

 

 

http://www.youtube.com/watch?v=5g9uCcY7tFg

 

 

I assure you, Its WAY too easy to match the quality of most commercial tubes. Even these chipboard tubes hold more pressure then the spiral tubes sold by most manufacturers.

 

 

 

 

-dag

Edited June 28, 2012 by dagabu

[Mumbles]

Dag, that rocket certainly wasn't using a NEPT tube, but it wasn't handrolled either. Cpl always used 3" ID spiral cores from things like shrink wrap.

[dagabu]

Pretty sure he rolled that one Mum. I seem to remember some video of him doing so and then Dan T taking on the project soon after.

 

-dag

[MikeB]

Dag, that rocket certainly wasn't using a NEPT tube, but it wasn't handrolled either. Cpl always used 3" ID spiral cores from things like shrink wrap.

 

I agree with Mmblz on this one. Cpl is one of our club members and I have seen plenty of his work. His methods may have been somewhat unorthodox but the results were spectacular.

 

I hope I don't insult anyone, but those chipboard tubes are a little scary looking. I have rolled my share of tubes and there is a good tutorial in the PGI Anthology. Following it you can produce a serviceable tube.

Edited June 28, 2012 by MikeB

[dagabu]

I agree with Mmblz on this one. Cpl is one of our club members and I have seen plenty of his work. His methods may have been somewhat unorthodox but the results were spectacular.

 

I hope I don't insult anyone, but those chipboard tubes are a little scary looking. I have rolled my share of tubes and there is a good tutorial in the PGI Anthology. Following it you can produce a serviceable tube.

 

Mike,

 

No offence taken, they were an example of the most basic tube one can make and that they can even take whistle fuel and not burst. I will look for my correspondence with Mac, I am pretty sure he made the tube for that one after he CATOd the first #20 weight he lifted on a 3" motor.

 

Now that you mention it, didn't he wrap them with something, perhaps fiberglass?

 

-dag

[MikeB]

Mike,

 

No offence taken, they were an example of the most basic tube one can make and that they can even take whistle fuel and not burst. I will look for my correspondence with Mac, I am pretty sure he made the tube for that one after he CATOd the first #20 weight he lifted on a 3" motor.

 

Now that you mention it, didn't he wrap them with something, perhaps fiberglass?

 

-dag

 

 

Thank you Dag, more people should be as understanding as you are. Sometimes we say things and mean well, but they are interpreted wrong.

I cannot say I saw all the motors he made. In fact it was probably a small percentage. None I was witness to were wrapped with anything. He merely used a very heavy walled spiral core and pressed them without a sleeve. The scary part was that the core was drilled with a hand brace! These were the 3" id ones.

 

Now, Dan T did in fact roll some 2 inch tubes which were layered with fiberglass and resin. This was about two or three years ago and I had attempted to order them special from NEPT. After they took my order and waited six months I realized they would never materialize. Not to change the subject, but that is how NEPT operates.

[Mumbles]

The only thing I've ever seen wrap the tubes with is a variety of colored duct tapes to make them look pretty. I've seen numerous rockets from him at WPAG and HPA shoots. Save for different core diameters and lengths I think all the motors were constructed fairly similarly.

[dagabu]

Thanks guys for the correction, don't know why I have that in my mind... Pressed them without a sleeve? That is one stout tube!

 

-dag

[gregkdc1]

Dag tell me more about the PVC cato's you have had, how close you were to the rocket etc. The reason why I ask is that when I first started playing with pvc sugar rockets I cato'd a few of them myself, and the pvc DID shatter into hundreds of little pieces of shrapnel. One thing I noticed is that the PVC didn't carry its energy very far not many pieces flew more than 30 feet even though some of them were able to punch through Masonite that was only a few feet from the motor. Once I got the hang of it I have made hundreds of motors with no catos. In fact I have even made reusable motors with pvc and one of them has been fired more than 30 times. I think PVC is kind of a paradox. It can make good rocket motors but it should only be done by people that have adequate experience, similar to flash powder. The thing is by the time most people acquire enough experience they usually have already bought reusable aluminum hardware that will outperform PVC in every way. At the minimum you should deliberately keep your operating pressure low and have a minimum stand off distance of 100 feet with electric ignition.

 

Back on the topic;

 

I need to know more about your motor design before I might be able to help.

 

You say the top grain is not cored so I am assuming this is a bates grain motor?

 

 

 

First are these sugar motors? The tracking grain has a tendency to go out with sugar propellants especially if it is recrystalized propellant. If this is the problem try adding some red iron oxide or coarse charcoal only to the propellant in the smoke grain.

Edited June 28, 2012 by gregkdc1