Jump to content


Photo

Crossette question


  • Please log in to reply
27 replies to this topic

#1 novacat14

novacat14

    Member

  • General Public Members
  • PipPip
  • 29 posts

Posted 24 February 2006 - 05:27 PM

Hey all, now i have done some research on the crossette star and i am looking into getting a Crossette Star Pump from wolter's but i am not sure on what the finished star looks like and the detail of the construction, like what type of break charge to use, just old bp or maybe flash, but i though that flash would be way too strong. I was wondering if anyone had a picture of a finished crossette star or comet?

Thanks for all the help guys :P

#2 alany

alany

    Pyro Forum Regular

  • General Public Members
  • PipPipPip
  • 740 posts

Posted 24 February 2006 - 11:18 PM

For small crossettes, say under 1.5" you will need to use flash. Larger crossette comets can be broken with granulated whistle. No matter what the size, dialing-in the break charge can be very frustrating, but smaller ones are a royal pain in the butt!

Drying crossettes (and some other stars):

http://nexus.cable.n...90/p0004544.jpg
http://nexus.cable.n...90/p0004545.jpg
http://nexus.cable.n...90/p0004600.jpg
http://nexus.cable.n...90/p0004622.jpg

Pasted crossettes:

http://nexus.cable.n...90/p0004602.jpg

With Rich's tooling you just take the dry crossette comet, put the measured amount of break charge into the hole (with or without a central fuse in the pin hole - try both), then glue a disk over the end. You then wrap the comet in a pasted piece of paper pleating it down over the end to contain the disk. The paste wrap doesn't cover the bottom or the bottom edge of the comet, which are left exposed for ignition.

Passfire has a good article on crossette construction.

#3 adamw

adamw

    An old Leodensian

  • General Public Members
  • PipPipPipPip
  • 1,297 posts

Posted 25 February 2006 - 09:19 AM

Flash can be used, unless you don't like the...flash... produced by the break. In that case grained whistle will be OK. There are some 'dark' flash mixtures to combat the problem of brightness, but these usually contain sensitisers such as sulphur compounds.
75 : 15: 10... Enough said!

#4 novacat14

novacat14

    Member

  • General Public Members
  • PipPip
  • 29 posts

Posted 26 February 2006 - 01:41 AM

thanks guys, as always you produce the exact thing i am looking for, quick extra questions, are special star comps required or prefered for crossettes?

#5 alany

alany

    Pyro Forum Regular

  • General Public Members
  • PipPipPip
  • 740 posts

Posted 26 February 2006 - 02:53 AM

Some compositions are better than others. Bright, tailed and medium to fast-burning are ideal. The comet end-burns before it breaks, so the composition must be fairly fast, that said I've used Tiger Tail with good results in smaller crossettes.

#6 karlfoxman

karlfoxman

    Resident Maltese shell builder

  • General Public Members
  • PipPipPipPip
  • 1,139 posts

Posted 26 February 2006 - 09:09 PM

Another way to break a crossette is to make small flash crackers, like tiny tiny bangers inside the cavity. I have not produced any crossettes yet but i am looking forward to making 1.5inch crossette candles.

#7 alany

alany

    Pyro Forum Regular

  • General Public Members
  • PipPipPip
  • 740 posts

Posted 26 February 2006 - 11:23 PM

Yeah making shots for the hole works very well, but its a *lot* of work.

Crossettes are already a hell of a lot of work, rolling shots makes it even worse. However it is the easiest way to get the breaking power if you are having problems with jetting. Unfortunately it doesn't scale down well, rolling a shot for 3/8" crossettes is near impossible. Rolled shots works better with crossettes that don't have the cruciform cavity, there is more room available, but they often shatter into many different sized pieces rather than uniformly like the cruciform ones. Square hole crossettes are a good compromise, and the tooling is easier to make.

Shattering isn't always a bad thing, with tailed stars, like glitters it can be quite sky-filling, but I don't find it as asthetically pleasing as the cross where all the pieces are ejected orthogonally and all burn-out about the same time.

#8 karlfoxman

karlfoxman

    Resident Maltese shell builder

  • General Public Members
  • PipPipPipPip
  • 1,139 posts

Posted 27 February 2006 - 03:49 PM

I remember a good video on building glittering crossette candles, Mark Mara used these hole shots because he had lots of problems. I guess you just have to spend the time finely adjusting the break until you get consistent results. May take a large amount of time and chemicals but at least it will be worth it when every crossette breaks perfectly. I would be tempted to use granulated whistle as flash i feel is just too strong.

#9 novacat14

novacat14

    Member

  • General Public Members
  • PipPip
  • 29 posts

Posted 27 February 2006 - 05:59 PM

wow, thanks for all the great replies, i am thinking of trying a small amount of flash and if i dont like the effect i will switch to whistle granuals. it is my thoery that flash will be too strong for my liking. Thanks again all ur great!

#10 sasman

sasman

    Sasman

  • General Public Members
  • PipPipPip
  • 490 posts

Posted 26 June 2006 - 11:48 AM

I am going to try to make some crossetes soon but have read that they can be hard to break without jetting..I have looked at Ladykates webpage and there are few video clips of crossettes that didnt break correctly but non of a good break?...

Have any members got any video of there homemade crossettes in action?..that they would like to post..

cheers

#11 karlfoxman

karlfoxman

    Resident Maltese shell builder

  • General Public Members
  • PipPipPipPip
  • 1,139 posts

Posted 26 June 2006 - 12:09 PM

The ones I made used broke with 0.8g flash. They did not jet, I have tried one with 0.4g and that di d not break properly. I think I may have been lucky, ill do more tests.

#12 Mumbles

Mumbles

    Pyro Forum Regular

  • General Public Members
  • PipPipPip
  • 955 posts

Posted 27 June 2006 - 10:50 PM

I just made my first crossettes the other day under the instruction of someone who actually knew what they were doing. I'll share my experience and instruction in a hope that it will help. I had perfect results, no jetting, proper breaks. The method is fast and easy.

3/4" tooling from Rich Wolter was used. The crossettes were win 39 pressed with an arbor press to compress. All of them were sized for the same length and approximatly same break times. There were let to completely dry. A piece of thermolite was added to the bottom and placed into the nipple. Paper fuse and thin black match are also said to work. 70/30 Perc/Al flash is placed into a plastic sandwich baggie. The corner is cut off. The cutting of the corner makes a funnel of sorts. The ENTIRE cavity is filled with flash. A chipboard disk is placed over the top of the crossette. The disk is cut with an arch punch. The disk is "pasted" on with two turns of masking tape covering almost the all of the sides. About 1/8" is left exposed. Two small pieces of black match are taped to the bottom for an expedited priming.

#13 Chyros

Chyros

    Member

  • General Public Members
  • PipPip
  • 13 posts

Posted 30 July 2006 - 08:36 PM

Never seen these things, but the ones in Alany's pics look very pretty!

#14 sasman

sasman

    Sasman

  • General Public Members
  • PipPipPip
  • 490 posts

Posted 15 July 2007 - 10:34 PM

eh

Edited by sasman, 22 July 2007 - 09:53 PM.


#15 Frozentech

Frozentech

    Pyro Forum Regular

  • General Public Members
  • PipPipPip
  • 389 posts

Posted 16 July 2007 - 12:07 AM

I finally got around to making some crossettes.. they were made with rich wolters 1" pump and used a tigertail comp.I used 2 turns of gummed paper tape to wrap around the crossette ,fine grain powder was used to passfire to the flash charge.. which was 0.5 g & 0.7g standard 70/30 flash..

A carboard disk was hot glued onto the top to stop the flash falling out..The bottom of the crossette was primed using some 3F BP using 10% nitrocellulose laquer as the binder..I fired it out of a 1.5" diameter tube .. which was way to big for a 1" crossette..Video is here crossette..They went off with a fair crack...i will make a few more but with less flash 0..2g.0.3g.0.4g..to see if they work better..i will try them in a rocket header later this week...


Good start ! You don't have to deal with the jetting problems there. I think as you dial them down you'll find the sweet spot where they crack into 4 equal pieces. Curious to see how a shell full looks in full dark.
"The word unblowupable is thrown around a lot these days, but I think I can say with confidence..."
KAABLAAAMMM!!!
"OK... that shows you what could potentially happen."
--Homer Simpson




1 user(s) are reading this topic

0 members, 1 guests, 0 anonymous users