9 replies to this topic

[bangkokpyro]

m

Edited by bangkokpyro, 22 December 2016 - 12:09 PM.

[Sparky]

I love those, do you have more detail how that one was made. It burns for an age!

[Arthur Brown]

I like that! Yes they seem to have a long burn time, is that usual? I like the spiralled smoke trail.

[bangkokpyro]

Yes they do burn for a long time; almost a minute.
Realy they are more like Tourbillions than Girandolas
The B.P pressed inside of the tube is not ball milled it's super coarse. Ingredients are run through a 12 mesh sieve a few times to mix it and the grains of charcoal, Sulphur and Nitrate are still visible after mixing.
The 2 exit nozzles are approx 1/2 inch diameter and offset from center about 7 degrees to give it the spin.
This is the smallest size I have seen made here, some are monsters up to 40 foot across that utilize a steel pipe between the bamboo hoops .......not something you want to be anywhere near when they light it !

Edited by bangkokpyro, 20 June 2012 - 04:05 AM.

[Sparky]

OK I'm trying visualise this...

A pipe full of loosely packed and not very well integrated green BP. The tube has 2 exists at each end at right angles to the centre of the pipe but off set so the exhaust gases generate rotation. The idea being that the pipe produces enough thrust to rise slowly but also rotate.

I imagine making one with cardboard tubes may result in burn through very quickly maybe even at the exit nozzles. I've seen Saxon wheels with re-enforcement around the nozzle so they don't erode too much.

[pyrotrev]

Excellent firework Bangkokpyro, well done!: I can remember one or two "helicopter" type fireworks using a couple of angled nozzles from a long time ago, but they always veered off and ended up going sideways most times. That thing of yours is obviously very well balanced to go that high and soooo straight. Makes me wonder what you could do with an APCP fuelled one, now where can I find some titanium tube I wonder????

Edited by pyrotrev, 20 June 2012 - 07:40 PM.

[Atom Fireworks]

Excellent firework Bangkokpyro, well done!: I can remember one or two "helicopter" type fireworks using a couple of angled nozzles from a long time ago, but they always veered off and ended up going sideways most times. That thing of yours is obviously very well balanced to go that high and soooo straight. Makes me wonder what you could do with an APCP fuelled one, now where can I find some titanium tube I wonder????

Trev I know Cumbria is a large place with much " free" land but come on dude seriously??????? p.s if you do, give me a bell I would like to come and see ha ha

[bangkokpyro]

OK I'm trying visualise this...

A pipe full of loosely packed and not very well integrated green BP. The tube has 2 exists at each end at right angles to the centre of the pipe but off set so the exhaust gases generate rotation. The idea being that the pipe produces enough thrust to rise slowly but also rotate.

I imagine making one with cardboard tubes may result in burn through very quickly maybe even at the exit nozzles. I've seen Saxon wheels with re-enforcement around the nozzle so they don't erode too much.

No it is not loosely packed it would explode within seconds of being lit if it was. It's pressed hydraulicaly at around 8000 PSI on the comp. The nozzles are offset 7 degrees from the centre line on the underside of the tube. The Charcoal , Sulphur and Nitrate are so poorly incorporated that if a spoonful is ignited on the ground it barely burns. Once confined inside a tube it burns faster...pressure..faster burn rate...faster burn rate more pressure etc.

[Sparky]

Do you think hand ramming would achieve anything like the same results?

[bangkokpyro]

Do you think hand ramming would achieve anything like the same results?

Hand ramming! Just how would you propose ramming a 4 inch ID 4 foot long tube by hand?
The simple answer is no it would explode shortly after lighting the fuse.