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Posted

I've tried several different ways to make BM, and the only way I can get it right is to use multiple strands rather than one. A single piece of string, no matter how fluffy or embedded with BP, is prone to dead spots, and I don't like them. I figured three strings, saturated with slurry, and twisted into a siral, will make a nearly infallible BM.

 

The project starts with a tiny tupperware, one holding only 8 ounces or so:

 

http://www.5bears.com/firew/mmm01.jpg

 

In each end of the tupperware, near the top, 3 holes are drilled, and rubber grommets appropriate for the string you are using are instaled. The exit grommets are critical. Too tight, and it excessively squeegees the BP slurry; too loose, and you get too much.

 

The heart of the machine are the cross bars. These are hobby shop brass tubes, 1/4" diameter, that allow a #10 machine screw to pass through. Carefully measure and cut the bars. Drill four holes near the bottom of the tupperware, lower is better, capable of passing a #10 machine screw, about 0.187" or 4mm. In other words, the hole is SMALLER in diameter than the brass tubes OD.

 

Cut two pieces of 10-24 "all-thread", and secure the cross bars with 4 nuts, and 4 washers. The interface of the brass tube to tupperware wall will be sealed by this action.

 

http://www.5bears.com/firew/mmm02.jpg

 

There will be three spools of cotton string, and the machine is threaded like this:

 

http://www.5bears.com/firew/mmm03.jpg

http://www.5bears.com/firew/mmm04.jpg

 

To make three spools of string is easy. Use rocket tubes! I used three 4-ounce tubes, placed on a brass bar supported in a bench vise.

 

http://www.5bears.com/firew/mmm05.jpg

 

To wind them, an easy way is to chuck a rod in a hand drill, and press the tube on the rod. Start the drill, and allow it to pull string from a big spindle, providing tension and guidance with your free hand.

 

Once the string has been threaded, the little machine needs to be secured. This setup is very minimal; all I did was use a c-clamp to keep the machine steady. A more advanced machine would integrate all these separate items.

 

http://www.5bears.com/firew/mmm06.jpg

 

In goes the slurry. Too thick, and the string will quickly form voids that will not refill with slurry. Too thin, and the coating will be inadequate. I needed this batch to dry quickly for the 4th, so I went with extra red gum binder, and a 75:25 alcohol:water solvent. Note the red gum staining the string in this shot. I found the slurry stiffened up as I made match, so I sprayed 75% iso alcohol occasionally, poked it around with a popsicle stick, to keep the slurry flowing.

 

http://www.5bears.com/firew/mmm07.jpg

 

The match is simply pulled slowly. Small cable ties secure the free ends, and as the match comes out, it can be twisted. At least with a red gum binding, it will glaze a bit within a foot of extraction from the machine, so keep the twisting going pretty aggressively.

 

http://www.5bears.com/firew/mmm08.jpg

 

That will ensure the strands are glued together as the solvent evaporates. This particular match dries really stiff, but I think it will survive a sharp bend easily, being triple-stranded.

 

http://www.5bears.com/firew/mmm09.jpg

 

That's it, a miniature, simple matchmaker that is very effective, and takes some of the hassle out of BM. It's still an annoying, messy business, but it's good to know your match simply will not fail. For anyone curious, this BP was the bamboo charcoal stuff, and it burns perfectly as match. I haven't piped it yet, but I suspect it'll be good.

Posted

Swede, great tutorial as allways. Thanks I thin I will adopt this method but I think I won't twist the match at the end, because my single stranded match is perfect, survives strong bends and all of that.

 

Keep them coming! ;)

Posted
Swede... you crafty, little devil. That setup just sings to my Rube Goldberg/DIY inner child. I believe I may try to rig up something along those lines and give it a whirl this weekend. Course it'll have to be during the lulls of cannon fire. Boy howdy does Greg-the-Accountant ever love living by me this time of the year! Arghhhh.
Posted

Follow-up: it made good match. I really wanted a potent binding action with this batch, so it ended up being about 8% RG. The RG really glued the strands well, and the nice thing about spiral match is you have serious BP inside the "strand", so the reliability goes up. In the Texas heat, it dried in less than 6 hours, but I'll leave it out a day or two just to be sure.

 

http://www.5bears.com/firew/mmm10.jpg

 

As a test, I took a short piece, and really abused it, just short of physically pulling the strands apart. It shed some BP from the surface, but otherwise, burned very nicely. Here's a video of the triple-strand match. Note a bit of variation in burn speed, as the flame encounters areas of shed external BP, but the overall intensity was high.

 

Abused BM video, 1 MB

 

http://www.5bears.com/firew/mmm11.jpg

Posted
That looks really nice, I tried something similar but the string would seize up as there was to much friction along the bars in the slurry.
Posted
Swede, that's ingenious. And the result is spectacular. Have you tried it in some quickmatch tubing yet?
Posted
Wow, thats got a really nice size flame to it. Once I get my new shed and start turning it into a pyro workshop, this will definately be on my to-do list.
Posted
Easy, and effective, and very well made, but I suspect it runs through the black powder pretty quickly. But who the hell cares? That's the price of reliability...
Posted
Such a cool set up.
Posted

Hehe, it looks like you wouldn't get your hands dirty :P

It looks very nice, currently I'm useing gum arabic for my blackmatch, never had any better.

I knot 3 strings togheter ( a meter long) and let it absorb for a while in the slurry, after a minute I pull the strings through my fingers and hang them to dry. Within 15 minutes I have enough for about 30 pipe matches.

Posted

Great little set up, you could use more thinner strings to get a thinner but still equally reliable BM?

 

I seem to be having great success with my single stranded BM, I use pine bp with 15% dextrin and it has an extremely steady burn rate and great flame propagation, i dont have too much trouble with flaking but when i cut it the centre is still white. its great for getting in small holes because you can just cut it at a very sharp angle and it still passes fire. its just a tad over 1/16th" in diametre.

Posted

Thank you all for the kind comments. I decided to triple strand and twist it because my previous match was just not that good, and the thought of working hard on a shell, only to have it misfire due to lame BM, gave me some pause.

 

I think the trick here is that the twisting action distributes significant BP into the inside of the match assembly. The 6 to 8% red gum was more than enough to pretty much permanently glue the strands together, but only if the twisting is done within 10 or 15 seconds of exiting the machine.

 

In the future, I'm going to use perhaps a different binder, or more water, in an attempt to slow the drying down a bit.

 

I also agree that thinner string, twisted like this, will still make a reliable and potent BM that would serve well. Twisting multistranded match is more effort, and uses more BP, but for me, at least, I think it is worth it.

  • 8 months later...
Posted (edited)

Wow that is so close to what i'm using at the moment tho' it is a bit more fancy compared to mine, lol. and I only pull one string thro'. I'm going to buy some of those rubber gromits and pull a few more stings thro'.

 

You have done a great job on this tut mate. very well laid out.

Edited by TrueBluePyro
Posted

Here is a video of my BM machine, its two stranded, (doesn't twist) and is extremely quick, easy, and not messy at all. I used 15% dextrin, and hot water with 25% metho as the solvent. Just pour the slurry in (consistency of paint) and turn the frame, its the best BM I have ever made. 300g of BP makes 60m of BM and it takes under 15 mins :D.

Anyway here is the video, it has some burn tests and stuff in there also:

http://www.youtube.com/watch?v=Gc-fgPrjLCI...re=channel_page

 

Oh and it has an annoying thing where it tends to fly away like visco! Here is a video of me attempting to light a pile of composition with a 2" peice of BM.

Posted
Does anyone know of any plans posted on the internet for a visco machine? I've seen a few photos but I don't understand how the threads wrap up the BP. I would LOVE to make a killer visco machine. And a better BM machine... and a star roller... and pumps, plates, rocket tooling. It never ends!
Posted (edited)

For BM I've used a plastic pint milk bottle. Cut off the side opposite the handle and thread the string(s) through the handle. 75;10;10 BP with the remainig 5 made up of dextrin. Biggest difficulty is getting thin enough string. -Too fat a string and the QM will not fit down a small mortar alongside a shell, then you risk something fouling in the bore.

 

Added;

 

http://www.pyrosociety.org.uk/forum/index....ost&p=18424

Edited by Arthur
Posted
Here is a video of my BM machine

 

I like your quick match ideas. I've been rolling plain craft paper for my tubes, your way is much better. I might have to try that slurry trick too.

Posted

I always thought about a BM/visco kind of fuse.

 

The main difficulty with a visco machine appears to be the BP flowing rate, and the special funnel construction.

 

Since well made BM is able to burn thru long tight holes in wood, it would make a good core. It would need a glue like red gum in acetone or something (maybe cheap ping pong balls NC laquer) to insure a fast drying time before the cotton threads would be spun around it.

Posted (edited)

You might want to upgrade you're micro-match machine to something like this :D

 

It is still experimental but i got most things right. Sorry for the poor video, i had to cut because i detected a glitch in the process. It is really a 2 man, preferably 3 man job to operate it. And a very strong motor, the pulling strength is enormous. I used gummed tape as a test but that is definitely not suitable as the second video shows.

 

video1 : (First test)

http://www.pyrobin.com/files/m2u00163.mpg

 

video2 :

http://www.pyrobin.com/files/m2u00168.mpg

post-4366-1239142179_thumb.jpg

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post-4366-1239142511_thumb.jpg

Edited by Piet
Posted (edited)

That is a VERY nice QM machine .

 

 

Kudos

 

EDIT;Why doesnt the GPT not work?

It seemed great.

Edited by Ventsi
Posted

Hey, Piet, you are waaaay off topic. 2 meters long 3 man operated machine? The thread title is "MICRO match machine" :)

 

GREAT job! I bet your inspiration came from the chinese fireworks factory.

Once properly tuned, you can start selling your bm to companies... I thought about doing something similar but I realised that in a single day such a machine can make more mach that I would likely need in my lifetime.

Posted
EDIT;Why doesnt the GPT not work?

It seemed great.

 

Its oke for some applications but it is to violent, it looks like 40 firecrackers connected to each other.

The gummed tape is sticking to each other so its not really a hollow tube were the fire travels at high speed, Also, poking holes in it is easy but inserting black match or visco for connecting shells inside the tube is not possible.

 

Hey, Piet, you are waaaay off topic. 2 meters long 3 man operated machine? The thread title is "MICRO match machine" :)

 

GREAT job! I bet your inspiration came from the chinese fireworks factory.

Once properly tuned, you can start selling your bm to companies... I thought about doing something similar but I realised that in a single day such a machine can make more mach that I would likely need in my lifetime.

 

My machine is also micro, the original machines are waaay longer :P I am still looking for some gnome's

 

I hate making tubes thats why i made this machine, and i do use a lot of QM. When i prepare a show i connect everything with QM and delays so only 1 fuse have to be lit.

Its also handy for making rapid fire cakes.

  • 7 months later...
Posted
Does anyone know of any plans posted on the internet for a visco machine? I've seen a few photos but I don't understand how the threads wrap up the BP. I would LOVE to make a killer visco machine.

Have look at this :-

Visco Fuse Machine http://pyroforum.nl/index.php?showtopic=893

Its in English BTW.

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