The Pyrotechnic Workshop Reference

[asilentbob]

I think that i should add this formula is at some point.

 

Originally posted by Mumbles:

 

You're wrong about initial velocities only mattering in a vacuum, but it also doesn't matter here.  Well, it matters, but it can be worked around to give a reasonably accurate.  There have to be some unrealistic assumptions, but still it will be relativly accurate. 

 

First we have to assume it went straight up and straight down.  Also that said tests were done in a complete vacuum, or at least no air resistance or wind.  Time up will be approximatly equal to time down.  Time down has an initial velocity of 0. So.........

 

H= 1/2At^2

 

If you want meters use 9.81 for A, or if you want feet use 32 for A.  t is of course half of your total time.  So you get 67 feet.

[asilentbob]

Originally posted by siffup

 

may some useful info by shimizu for chrysanthemum shells:

 

size of shell / size of main star / number of main star / burst

 

3" / 9mm / 150 / 35g

4" / 12mm / 170 / ????

6" / 15mm / 200 / 270g

8" / 19mm / 260 / 770g

 

Also note to self:

Request use of info on whitabuggywhip site.

AND make sure you get all the credits.

[Mumbles]

Here's another for the file.

 

"

L = length of the strip you'll need

w = desired wall thickness of the tube

p = paper thickness

d = diameter of the rod you roll your tube on (id of the tube)

PI = 3.14159

 

Number of turns needed = w / p

 

Average length of turn = PI * (d + w)

 

hence, L = PI * w * (d + w) / p"

 

I don't know who to directly credit. From what I can understand it is a friend of kkpaul from UKPS.

[asilentbob]

Originally posted by Mephistos Minion here:

http://www.apcforum.net/forums/index.php?showtopic=302

 

 

Gday,

Wasn't sure if this belongs here, but I don't want it to get lost in the forums , so I decided here it would go, mods, if you want to move it go ahead.

 

I did all the calculations and here is a fairly accurate table of Kraft weights to GSM (Grams Square Metre commonly used outside the USA)

 

30lb Kraft = 50 GSM

40lb Kraft = 65 GSM

50lb Kraft = 80 GSM

60lb Kraft = 100 GSM

70lb Kraft = 115GSM

 

If you have another weight then here is the formula using 70lb as an example:

 

70/500 = 0.14

0.14 x 457= 63.98

63.98 x 1.8 = 115

 

The reason it is this is: The weights for Kraft are determined by a stack of 500 24"x36" sheets (61cm x 91.4cm). So therefore each sheet weighs 70/500lbs (63.98g) because theese sheets are less than a metre square we must times by 1.8 to get it there (61 x 91.4 = 5575.4) so then 5575.4 x 1.8 = 10035 ( 1 square metre is 10000, ok its a little off but close enough if you are after standard GSM Kraft paper get the closest one). So we must also multiply the weight of the 24"x36" sheet by 1.8 to get the GSM (63.98 x 1.8 =  115.164) and there you have the weight of a meter square of 70lb Kraft. Just drop your number in place of the 70 to work out other weights not listed in the chart.

[asilentbob]

Originally posted by Frozentech:

 

From the Passfire chart for *single break* shells :

 

  3 -- 15

  4 -- 20

  5 -- 24

  6 -- 28

  8 -- 34

  10 -- 40

  12 -- 46

 

The mortar length is measured from above the bottom plug. A rule of thumb is 5 times the mortar diameter for shells under 8 inches, and 4 times the mortar diameter for shells 8 inches and up.

 

Source: Illustrated Dictionary of Pyrotechnics

[pudidotdk]

My uncomplete pyro book:

 

pyrobin.com/files/pyroshop book.doc

 

(copy paste into URL bar)

[Bonny]

I'm not sure if this is of any use to anyone, but may help in making/extracting chems or metal powders.

Source:

A Thousand and One Formulas by Sidney Gernsback

[pudidotdk]

I'm not sure if this is of any use to anyone, but may help in making/extracting chems or metal powders.

Source:

A Thousand and One Formulas by Sidney Gernsback

I've actually been looking for that! Thanks!

[ActiveA]

I'm not sure if this is of any use to anyone, but may help in making/extracting chems or metal powders.

Source:

A Thousand and One Formulas by Sidney Gernsback

I can't download that for some reason...

 

 

When i click on it i get a ton of random symbols.

[Mumbles]

I have the same problem with firefox, actually will all attachments here. Try opening it in internet explorer. I have a plug-in installed to allow me to right click and open it directly in IE. I had to use it for something else in the past, but it serves this purpose as well.

[asilentbob]

I have FF too, and same thing happens... sometimes if i "copy image location" and paste that into a new tab it works.

 

I thought lithium was the most active in what it can displace. Perhaps im getting confused with activity series... not electrochemical series. Or something. The serieses always throw me off... there are like 3 main ones... and it seems like authors often get them slightly wrong or something...

[BPinthemorning]

I have found alot of info on minimum mortar lenght, but the lowest id they go is 3 inches. Dose anyone know how lone my 1 inch mortar should be?

[Mumbles]

6x the ID mortar length so 6" minimum. Genernally the tube is cut 7x ID, so 6x mortar, and the final increment is filled by a standard wooden plug.

 

A longer tube will work, and will shoot it higher. Theres a study in one of the best of AFN books, #2 I think. It's by the kosanke's, so it looks scientific without any real science behind it.

[Bonny]

I use 13-14" mortars for my 1" cylinder shells. My mortars (I know not the safest) are steel pipes welded to a base.

[GalFisk]

I reposted what Bonny posted here (it's the electrochemical series).

 

A chemical incompatibility chart would be useful on the workshop reference.

[asilentbob]

BUMP

ATF field agents conversion chart

 

Wow, its been a long time since this thread was updated. Over a year. Now there is a bit of new blood around. Perhaps some members have some new info now?

[Swede]

Not strictly pyrotechnic, but this is my most-used utility, bar none. It is called "convert" and has thousands of engineering units, readily convertible to others. Volume, mass, pressure, length; an awesome tool, highly recommended.

 

http://www.5bears.com/convrt.jpg

 

Download convert.zip from my web site; virus-free.

[Arthur]

www.pyroguide.com has lots of info, little of it original or credited.

[Mumbles]

I thought I would toss a few things in here. I've been doing some tube rolling calculations, and I figured these values might be useful.

 

Common Thicknesses in inches

 

Kraft:

30# - 0.003

35# - 0.0035

40# - 0.004

50# - 0.005

60# - 0.006

70# - 0.007

 

Poster board:

4 ply poster - 0.017

5 ply poster - 0.022

6 ply poster - 0.026

8 ply poster - 0.034

14 ply poster - 0.048

 

Everyday Materials:

Cereal Boxes - 0.025

Paper Lunch Sack - 0.003

Grocery Bag - 0.006

Tissue Paper - .001

 

Manilla file folders:

10pt file folder - 0.01

12pt file folder - 0.012

14pt file folder - 0.014

 

Random things from Fulcanelli:

100lb Tagboard - 0.007

90lb Index Bristol - 0.007

125lb Tagboard - 0.009

110lb Index Bristol - 0.009

 

Chipboards: (Based on # of sheets per ~50lbs, sometimes given in pt which is .001")

#120? #125? - 0.018 I'm not sure on the correct number for this one

#90 - 0.022

#70 - 0.03

#60 - 0.035

#50 - 0.042

#45 - 0.052

#30 - 0.07

#20 - 0.1

[asilentbob]

Lots of tables for cylindrical shells.

 

http://www.bangkokpyro.com/shell-building.php

[stckmndn]

Great thread. Thanks, Bob.