Is there any equation or Rule of Thumb showing the thickness of the wall of a round shell with the diameter of the shell?

N = 5.6 D(cm)/J(kg/cm)

Thats only for pasting, I have no idea about wall thickness. Send an email to skylighter about how thick their shell cases are they sell. That may help.

But you probably won't be around long enough to read this so I suggest you delete this thread and the other about the double petal shell.

Don't worry pal. I'll be hanging here for long time.

Blindkeeper,
I forgot to ask- but where is the chart?

Allow me to just expand on what blindreeper said.

So, that N = 5.6D/J is for Warimono shells. N is the number of layers (and there is a certain way to put the paper on, at least there is one shown by Shimizu). D is of course the diameter of the shell (as said, in cm) and J is the "mean value of the tensile strengths measured in both parallel and perpendicular directions to the fibers in kg per 1 cm width." (Shimizu, FAST) The J is there because the strength of paper varies so much from bunch to another.

Polka shells are a bit different. They seem much less common over here but are described by Shimizu as something that really should be used more often. This is because he describes polka shells as to be used for things like willow, reports, comets, whistles etc (stuff other than a round flower). People tend to use a warimono type configuration for these things (not saying it's bad, just the way it seems to be over here). Anyways polka shells don't have to have as much of a wall:
N=1.6D/J

Don't worry pal. I'll be hanging here for long time.
Let's see now...

1. THREE new posts by a newbie
2. ALL of them single line questions on topics which could be easily found with a little effort, demanding answers from members, giving nothing in return and displaying the fact that you simply want to be spoonfed. You'll be hanging here because? Well, not for the contribution you're likely to make to the collective I suspect.
3. Double posting
4. Just about every post being similarly valueless
5.OBVIOUSLY being a dullard
6. Wasting MY time by giving a link to your website, which contains the sum of fuck all and not a lot.

I quote:
Pyrotechnics, The secret knowledge of color, light and joy is..... Is? Well, it's just plain MISSING isn't it, which is perhaps why you want to be handed some neato little articles to put on your "site".

Maybe if you'd arrived here with even the semblance of an idea how to get the most out of this forum you'd have a chance of sticking around.

Maybe if you'd posted your questions in the watercooler?

Maybe if you'd read the rules, the sticky guides for newbies yadda yadda yadda.

But you didn't do any of these things, which on reflection makes your hanging assumption a little premature

And it'll be a shame to see you go, genuinely, but I wonder how easy it will be to get round an IP ban seeing as you're in Dhaka?

Jeeez, THREE nitwits in scarcely a day.....best I get the derris dust out of my shed!

Was the implementation of moderation of all posts by newbies discontinued? It's amazing that the thread has progressed so far already...

Coming back to N, in the formula N = 5.6 D(cm)/J(kg/cm), if the dimensions of D (diameter) is [M0L1T0], and that of J (mean tensile strength ... for 1 kg per cm width) is [M1L-1T0], then the dimensions of N would be [M-1L2T0]!! However, if N is just the number of layers, N should be dimensionless! Did I overlook something?

It seems like I've made a mistake by asking those "stupid" quetions to the professionals like you.
I'm extremely sorry for placing those questions and waste your precious time.
I like to know a variety of things but doesn't look like that you guys are intersted towards letting others know.
Thanks blindreeper, sparky and T Pyro.
Thanks anyway.

They're interested in DISCUSSION. They are NOT interested in handing everything to you on a plate. The information is already out there, but you didn't bother trying to do a little research.

If you did some reading up, and then came back and started (or better yet, joined into) a thread on star formulas, let's say, on how to make a nice blue, or something along those lines, then they'd be more than happy to have one big happy lovefest with you.

So don't go and go and be such a big fucking huffy mess. You should've taken the time to read the rules

If you'd like to take a look at a really good, free resource, go to groups.google.com. Click on the "rec." link, then in that little menu near the top-left, select "pets...woodworking". Then click on "rec.pyrotechnics". That'll take you to a pyrotechnics bulletin board that's been around since the late 80s/early 90s. Under the little window where you type in words to search for (it seems that this concept may be a little foreign to you, but you'll figure it out), click the bubble next to "search only in rec.pyrotechnics". Then click back in the search window, and type in whatever you want to search for.

I just popped in a search for "wall thickness shell diameter" and got back nearly fifty results. Surely one of those results has something to do with what you're looking for, and by having to pick through the posts looking for what you want, you'll almost certainly learn quite a few interesting things, if you'll only take the time.

They're interested in DISCUSSION. They are NOT interested in handing everything to you on a plate. The information is already out there, but you didn't bother trying to do a little research.

If you did some reading up, and then came back and started (or better yet, joined into) a thread on star formulas, let's say, on how to make a nice blue, or something along those lines, then they'd be more than happy to have one big happy lovefest with you.

So don't go and go and be such a big fucking huffy mess. You should've taken the time to read the rules

If you'd like to take a look at a really good, free resource, go to groups.google.com. Click on the "rec." link, then in that little menu near the top-left, select "pets...woodworking". Then click on "rec.pyrotechnics". That'll take you to a pyrotechnics bulletin board that's been around since the late 80s/early 90s. Under the little window where you type in words to search for (it seems that this concept may be a little foreign to you, but you'll figure it out), click the bubble next to "search only in rec.pyrotechnics". Then click back in the search window, and type in whatever you want to search for.

I just popped in a search for "wall thickness shell diameter" and got back nearly fifty results. Surely one of those results has something to do with what you're looking for, and by having to pick through the posts looking for what you want, you'll almost certainly learn quite a few interesting things, if you'll only take the time.

nesler
Thanks a lot for your big help. I was not used to rec. groups. You really have done a great job for me. Best wishes.

mrhashmi, I don't think you did anything to deserve the hostility that's been unleashed at you.

What's your problem guys?

Its quite obvious, if you read the Rules then look at this twits posts. This newbie has started three new threads, all with one line questions, not one of them in the watercooler where he might have been looked on more kindly.

You have read the Rules yourself, haven't you Dinkydexy?

Why yes I have, sir. But surely, surely you're shoulders are broad enough to be able to cope with another human being's shortfallings without such anger?

I had a friend who couldn't handle being in any kind of position of authority, responsibility or seniority; he would just explode at the slightest provocation or irritation from those who he perceived as being 'beneath' him. I never did find out where all his unresolved anger and bitterness came from, but my guess is it was something to do with a lack of confidence in his own sexual ability. Just thought I'd mention it.

But surely, surely you're shoulders are broad enough to be able to cope with another human being's shortfallings without such anger
Eh. I replied to his first question, but the second and third made it pretty clear that he hadn't read the FAQ and/or was too lazy to search. I didn't rip him a new one, but certainly did rate his posts to reflect my thoughts. BTW, are the "rate the newbie posts" comments available for ordinary members to look at?

dinkydexy, after a while you'll get tired of newbies who haven't bothered to read the FAQ too, I promise you that. I've seen SENIOR members get flamed massively for not searching before asking a basic question too- (remember Axt?)

Fair enough. Mrhashmi, you're a dumbass.

What is this, "lame newbies of the world unite" week or what?:rolleyes:

Our problem Dinkydexy, is that MrH has made numerous blatant transgressions of rules that were put there EXACTLY to control people like him. His last post in this thread is just before yours and all he does is quote nesler's entire previous post and then put in a pointless one line reply from himself, saying thankyou. Can you hand on heart say that he's not a dimwit?

"Rules are for the guidance of the wise and the blind obedience of fools" is a favourite expression of mine, but nobody's entitled to use that doctrine here unless they've proved themselves - and that includes you. Mr Hashmi hasn't proved himself in any way, other than by being a parasite, and he isn't entitled to do ANYTHING here.

I've already explained some of the transgressions he's made and I wonder whether you noticed what they were? As Tuatara said, how familiar are YOU with the rules. Mr Hashmi wasn't slapped down when he put up his post about Pharoe Snakes, and maybe that's where people went wrong, as he went on to do pretty much the same thing over three posts. And remember, if he'd posted them in the watercooler, nobody would have said a bean to him. As it is, it's OBVIOUS that he hasn't read the rules, it's OBVIOUS that he has no interest in the way the forum works and it's OBVIOUS that all he wants to do is be spoonfed. If you want any more confirmation of how worthless he is here, take a look at his site - there's a minute of my life I'd prefer not to have wasted on him.

Instead of standing up for people like him, you and the rest of the newbies would be better served to keep them in control - you'll be senior members eventually and you'll inherit a pile of shit if you allow vacuous nonsense like that.

You can put my attitude down to repressed homosexuality, impotence, childhood abuse, lack of self-esteem or whatever the fuck you want, but you don't know me at all if you do. I'm not interested in power or modship or any other nonsense, but I do have a strong opinion when it comes to keeping this kind of drivel to a minimum.

Get a fucking grip, and MrHashmi, if you ARE still around, stay in the watercooler.

Arkangel, why make long posts about people who no longer exist here? :D

I think it's because I have a small cock and can't get it up:)

It was also (as you well know;)) to make a point to Dinkydexy and others, that they need to get a grip on lamers instead of humouring them!

Arkangel, why make long posts about people who no longer exist here? :D

Ah, which did you ban? Mr. Hashmi or dinkydexy? or BOTH?!

And has NBK2000 fallen into a black hole?

Sorry about the short reply, I banned Mr Hashmi for the obvious reasons. I didn't ban DinkyDexy, I like people who write posts with good english.

Arkangel:

Have got your mail, will reply in about 10mins

Thankee kindlee sir.

Arkangel, the mother of all ironies is that I had reconsidered, recanted and told Mrhashmi that he was a 'dumbass' before you jerked off all over my face.

PS. Bert, your use of 'which' is erroneous; should be 'whom'.

PS. Bert, your use of 'which' is erroneous; should be 'whom'.
"Eh" and "Ah" aren't in the dictionary either, for that matter... I tend to grunt monosyllabically while mutilating the Queen's English. But compared to these other dratted colonials, I feel my transgressions are minor, Ay?

You've spelt 'aye' wrong.

Dinkydexy, Zaibatsu didn't actually say that YOU wrote good English, so there's no need to overload on the grammar lessons. He said "I didn't ban DinkyDexy, I like people who write posts with good english", not "I didn't ban dixydexy BECAUSE he writes posts with good english" :p

(Should have been "English" anyway)

If I'd felt your recantation (is that a real word professor?) was genuine then I wouldn't have jerked off on you. As it is, you've got a well deserved pearl necklace ;)

You've spelt 'aye' wrong.
I'm an American. We've done a number of things to/with the language we inherited from the British. It's "Aluminum" over here, not "AluminIum", etc. If you can't deal with these slight cultural differences- We gave you a warm breakfast in 1776. We handed you a hot lunch in 1812. We'll be glad to provide a SIZZLING supper anytime you're hungry for it.

25 posts in all, 1 question by a "spoonfeed me" newbie to start it all, 1 expulsion to end it, 1 peeved English professor to lecture us on the intricacies of the English language, and a bunch of clarifications to cap it all. And the thread says "Round Shell Making".

dinkydexy, the name "E&W Forum" stands for "Explosives and Weapons Forum", not "English lectures and Wisecracks Forum". It's not so much as HOW you write that matters, but WHAT you post that matters here, as long as the English is acceptable. :rolleyes:

1. Arkangel, who's dixydexy??

2. T Pyro,
"25 posts in all, 1 question by a "spoonfeed me" newbie to start it all, 1 expulsion to end it, 1 peeved English professor to lecture us on the intricacies of the English language, and a bunch of clarifications to cap it all. And the thread says "Round Shell Making".

i. Please explain how this post of yours contributes in any way to a discussion about 'Round Shell Making'.
ii. Please explain why it's okay for you to make wisecracks, and feeble ones at that, ('"E&W Forum" stands for "Explosives and Weapons Forum", not "English lectures and Wisecracks Forum") but not for others.

3. Bert, thank you for your offer of hospitality. Please could I have a plate of bacon sandwiches and a cold beer.

This does not look good. :mad: I meant my last post as a friendly reminder that we should get back to the discussion at hand. While mrhashmi might not have been justified in asking the question in that manner, it still is a topic worth discussing. Read my first post in this thread. And if you still want to continue arguing, I suggest that we at least take it to the watercooler, and even then, it's not recommended.

...still awaiting your explanation(s). If you choose to give any.

Dinkydexy have you contributed at all or just sat there annoying people?
Now can we just forget it all and start talking about round shells! It might be easyer to deleat this topic and start new.

Q. "Dinkydexy have you contributed at all or just sat there annoying people?"

A. Neither. Nor did I preach to others about their posts being off topic, as you are.

Here's some friggin info on the subject taken from Shimitzu...too late for mrhashmi though.

{The paper is prepared as follows: Paste а sheet of paper on one side with а paste which does not contain too much water(Fig.106-1). Fold the paper with the paste in а kind of sandwich(2). This is to prevent the paste from drying. Cut the paper in strips of а precise width(3). The strips(4) are separated to expose the pasted surface, The pasted strips must be well stuck to the sphere by rolling the shell with a rolling board.
When one layer of paper has been added the shell must be in а drier or in the sun The same operations are repeated until the required number of layers have been added this is simply obtained from the following traditional and theoretical formula:
N=5.6 D/J
Where N is the required number of layers to be added in ordinary cases (ог а standard number), D the outside diameter of the inner shell in cm(в.Fig.88) and J is the mean value of the tensile strengths measured in both parallel and perpendicular directions to the fibres in kg per 1 cm width. The tensile strength of the paper varies considerably with the thickness brand and type, it must therefore be measured even by quite а simple method such as pulling the paper strips with а spring
For example when we obtain the strengths 6.2 kg/cm in parallel and 3.9 kg/cm in perpendicular directions to the fibres, we have the mean value (6.2+3.9)/2=.5.05=J. For а 6 inch shell D=13.5 cm.
Therefore, N=5.6 X 13.5/ 5.05=15.}