How to make jumping crackers?

[pyrosailor99]

See this:

 

http://pyrotechnics.no-ip.org/files/%29%20with%20red%20string%20%28wells%29_1.jpg

 

or this (bottom left)

http://pyrotechnics.no-ip.org/files/sampleboard01.jpg

 

How this devices are made??

what comp?

what method to build?

[nater]

One way is quick match folded and tied on a jig. Edited October 2, 2011 by nater

[50AE]

In my beginner days I had success with thick BP+dextrin water paste on paper and then folding it.

 

With quickmatch I tried once and I had a failure. It just exploded at once.

[Killerinc]

http://www.pyroguide.com/index.php?title=Jumping_cracker

[Peret]

Oh boy, I remember those from my youth.

 

The principle is that the bends are tight enough that the BP filling burns like time fuse, and the straights are slack enough that it burns like quick match. For this to work, the powder can't be granular, or it will have voids at the bends and just blow through. This would be the problem with quick match, if you use the commercial kind with several strands. It also must be strung and tied in such a way that it doesn't unravel after the first couple of bangs, or the same thing will happen. Weingart (I think) says to make a narrow kraft tube of 4 to 6 turns pasted down the edge only, fill it loosely with granulated powder, and then roll it flat with a hard and heavy roller to crush the grains. This would probably be easiest with home made BP without a binder. Then wrap the bundle of tubes (you are making more than one, yes?) in a damp cloth until they can be folded without tearing; then fold them, tie them and dry them. Weingart shows how to make a jig to get them evenly folded.

[pyrojig]

Awesome pic's BTW!! Got me kind of excited to see some "good 'ol fireworks"

[Pyrophury]

I had a go at making these a few years ago after I made my first batch of black powder - http://img28.imageshack.us/img28/3306/jumpingcracker.mp4

[NightHawkInLight]

Huh, it always surprises me to come across a firework I've never heard of before. Neat. I might have to make one.

[Mumbles]

I normally see them called English Crackers, Rip Rap, or actually most often as "grasshoppers". The chinese sold them for a while called "jumping frogs" according to Hardt. I've only tried a few times, and for the most part failed miserably.

 

My experience contradicts most of what has been said in this thread already. For me, trying to use meal powder went poorly. Using a slurry such as 50AE suggested and the pyroguide thing says only resulted in something that resembled a slow spolette with occasional pops. Perhaps I rolled the paper too tightly. What I finally got working somewhat well was to actually follow the instructions from the literature (imagine that). There is some info on page 139 of Hardt. It says to use fine grain powder, tie at each bend, and then the entire thing together. A jig is incredibly helpful. The most original info I've found is probably from Weingart on page 109. I haven't checked other older sources like Kentish, but it may have some info too. The jig in Weingart is incredibly simple, and really ingenious. Weingart says to roll a paper tube from 20lb paper. The common thing in that weight is computer paper. Normal run of the mill paper will fall apart. I had to go to virgin kraft, though I didn't try any of the better recycled kraft papers. Fill that with grain powder. Weingart specifies 3Fg, which is -20+50 mesh, and twist the tubes shut. Wrap the tubes in a damp cloth. I found that a wash cloth run out got to very close to the right point. It takes longer than you think to properly wet. You really want to soften the granules in addition to the paper. I let them go for at least an hour. Weingart recommends several hours. I found that it also helped to put everything into a plastic bag to keep the water from the towel or wash cloth from evaporating. After I was satisfied everything was good, I rolled a case former over the pipe to flatten it. I then bent it, really compressed it in the jig, wrapped a few turns around the thing, did another bend, and another few wraps, and so on. I don't know if this is necessary, but it's what I thought was required at the time. Looking back, it sounds more like the entire thing is just wrapped with a few turns of string, not each fold. Let them dry, cut off one end and fuse. Don't be too anxious in getting them dry. I let mine air dry for a few days. I'd be worried that force heating may cause cracks to develop inside.

 

The tubes were made from 4" wide piece of paper rolled on a 1/4" dowel as described by weingart. Only the last 1" or so of the paper was wet with paste. I did use real paste, not white glue. I don't know if it makes a difference, but I felt like the wheat paste on there helped to keep everything's shape and hold it together once it was re-wet and dried. I did use granular BP. I use my -36mesh fines from making lift and break. The fines were not removed. I felt like the grains were important to the function. It wasn't until I built a jig did I really get them working. I think it really helps to solidify the bends making nice delays, while retaining a somewhat "loose" or porus straight section to help with the bang.

[madmandotcom]

tieing thumb knots in the QM worked for me

[chuck45]

There is a fairly detailed discussion in Weingart, as has been stated, and also I think mention in The Chemistry of Powder and Explosives. Probably playing with a combination of above factors will yield results for you.

 

As your tube dimensions will not be identical to others, just try using the basic principal, with what suits you. I have achieved partial success with thick blackmatch, but never got back to perfecting it. I would think fine grain powder would be worth a try, will have to get back to these :-)

[WSM]

The closest thing to 20# Kraft I've seen is the masking paper available from the Big Box Home Centers. I used a micometer to gauge the thickness and twenty pound is the nearest equivalent weight paper. The masking paper comes in two types, a brown version and a green version. Experimentation is required to determine the suitibility of each but I vote for the green as it's somewhat more water resistant.

 

Enjoy!

 

WSM

[dagabu]

The closest thing to 20# Kraft I've seen is the masking paper available from the Big Box Home Centers. I used a micometer to gauge the thickness and twenty pound is the nearest equivalent weight paper. The masking paper comes in two types, a brown version and a green version. Experimentation is required to determine the suitibility of each but I vote for the green as it's somewhat more water resistant.

 

Enjoy!

 

WSM

 

My 6" rolls of mask are 20# recycled kraft but it is not the best choice for crackers, virgin kraft works so much better as you can bend it while damp without tearing. I tried jumping crackers when the topic came up on Passfire and following the directions exactly from Weingart I still got only so-so crackers. I had much better luck with slow flash coated cotton string rolled in a 6" strip of 30# virgin kraft glued with diluted white glue.

Overall, after just s few of these, I gave up, too little return for the work. Double Voice Crackers, now there is a fun and easy device!

-dag

[WSM]

My 6" rolls of mask are 20# recycled kraft but it is not the best choice for crackers, virgin kraft works so much better as you can bend it while damp without tearing. I tried jumping crackers when the topic came up on Passfire and following the directions exactly from Weingart I still got only so-so crackers. I had much better luck with slow flash coated cotton string rolled in a 6" strip of 30# virgin kraft glued with diluted white glue.

Overall, after just s few of these, I gave up, too little return for the work. Double Voice Crackers, now there is a fun and easy device!

-dag

 

Double voice crackers, huh?! A friend of mine (Donner, was it?) came up with a modern variation that worked well. He used a bit longer tube and added a wooden base with a close fitting dowel set in. The short dowel section added a sort of guidance to the DVC so when you ignited the side-mounted fuse, the cracker shot straight up like is was a rocket and fired the "second voice" reliably at about the same height every time. He used a tool set to set a measured length of Visco in a clay plug in the center of the tube for the time delay between the first and second "voices". The wooden base is reusable (if you're not required to abandon it due to the circumstances of the moment ).

 

Great fun, but don't do them in town .

 

WSM

[optimus]

Some good reading on the subject over at UKPS and pyroforum.nl can be found here:

 

http://www.pyrosociety.org.uk/forum/topic/3073-jumping-jacks/

[dagabu]

Double voice crackers, huh?! A friend of mine (Donner, was it?) came up with a modern variation that worked well. He used a bit longer tube and added a wooden base with a close fitting dowel set in. The short dowel section added a sort of guidance to the DVC so when you ignited the side-mounted fuse, the cracker shot straight up like is was a rocket and fired the "second voice" reliably at about the same height every time. He used a tool set to set a measured length of Visco in a clay plug in the center of the tube for the time delay between the first and second "voices". The wooden base is reusable (if you're not required to abandon it due to the circumstances of the moment ).

 

Great fun, but don't do them in town .

 

WSM

 

Oooooooooohhhhh! That sounds like fun, do you have drawings or dimensions?

 

-dag

[WSM]

Oooooooooohhhhh! That sounds like fun, do you have drawings or dimensions?

-dag

 

Well, the basic information is available with a google search:

 

http://www.creagan.n...oublevoice.html

 

I believe Dan Creagan (of PGI fame) wrote this article some time ago. Just add to this a wood base with a 5/8" dowel sticking 5/8" up into the bottom of the tube. The BP lift causes the tube to launch straight up without tumbling. The clay plug in the center needn't be more than about 1/2" thick (if solidly rammed) and the Visco only sticking out about 1/2" of either side of the clay plug, maximum, for an effective result. To ensure proper ignition of the Visco (not usually needed) one may use a small brush to apply some prime to the ends of the Visco, dry thoroughly and finish the assembly of the device.

 

Have fun, be safe and tell us all about it .

 

WSM

[nater]

i saw a similar consumer labeled device earlier this summer. it had the cracker on the bottom and instead of a second salute, it was a festival sized color break. the little things were neat, more unpredictable than a stinger rocket. as fun as they were, i admit i wouldnt want to see them readily available in every back yard.

[dagabu]

ARISE 5 year old thread, from the dead!!!

 

I am going to bring a couple jigs for English Crackers, Rip Rap, or grasshoppers to PGI next month, I finally found the right paper and have been rolling all sorts of tubes to make them right there!

 

There will be all sorts of surprises for those that want to make some and I am even making touch paper to light them. I'll speak with C-class to get a small section for us to blow them up if anybody is interested.

[patsroom]

Those things are fun. I made a tube, ran one string of BM the full length, put a measure amount of black powder in, folded the tube over did the next section until I had it fill. My son watched the whole time, when outside with it and lit it. Told my son to back up. He said that it wasn't going to work and I barely put any powder in it. So I said OK , boy oh boy can my son dance. That Thing chased him with every side step he took. LOL! Still laugh when ever I think of it. .........Pat

 

Oh no a Zombie thread!

Edited July 19, 2016 by patsroom

[dagabu]

Dyslexic zombies, on the hunt for Brians....

[dagabu]

I also made a 3/4" ID, double voice cracker tooling set as well, just need to mount the dowel on a section of board and I'm done!

[dagabu]

Here is the double voice cracker in action.

 

[Asaster420]

Still waiting on the rip rap....😎

[dagabu]

Time ran out on making them at PGI, I had three of them made ahead of time but they tore as I had overfilled them with comp. They lit but went WAY too fast around the bends. This will have to be a winter project now.