152 replies to this topic

[tajmiester]

Dunno, I only ordered the thing today. I'm doing my current experiments by hand (not exactly efficient).

Tris

[alany]

Alany, Ideally I would use more than one but the problem is I cannot see how you can keep the threads seperate, perhaps some sort of comb or similar but I cannot really visualise it. Surely the threads would pile on top of each other and get in a god awful mess!

It is how the real visco machines work, they have a ring of guides that inject the yarns at different heights so they wrap around the core in parallel. Here is my prototype spinnerette:

http://nexus.cable.n...90/p0003540.jpg
http://nexus.cable.n...90/p0003541.jpg

Note the holes in the Aluminium, they are in a spiral pattern, so each yarn meets the core at a different height.

Edited by alany, 13 January 2004 - 12:08 AM.

[lord_dranack]

I have built a visco rig out of mechano! It wraps 8 threads around the core in one direction, introduces at different heights, then up to 8 in the other direction for an outer layer.
I tested it last night with my normal blackmatch as the core, and it worked quite well, covering the entire string. I am out of ping-pong balls so I couldn't coat it.
After this test I made a few modifications to it but sadly my small 12v motor can no longer provide enough power so as soon as I finish this post I will go and dig out that old vacume cleaner motor
For the core I'm probably going to use three cotton threads coated in bp paste and spin them when still slightly damp, and so flexable.
If anyone is interested in seeing it I can email you some photos of the machine...

[Phoenix]

Sounds great! How does the fuse burn (if you've tried it yet).

Cellulose dope is what I use as NC Laquer. Get it from a model aircraft shop. I found that the tin of dope worked out cheaper than ping pong balls, and I didn't have to prepare it myself. Perhaps you can get cheap ping pong balls though...

[Stuart]

I make my Nitrocellulose and then use acetone based nail varnish remover to make NC Lacquer. I would like to see the photos please

Stuart

[lord_dranack]

I'll email pictures this evening- if anyone has any webspace feel free to host them!
The fuse I made with a blackmatch (large diameter) inner burnt like blackmatch but with much less side spit, and there was quite a lot of ash left. I'll be quite busy this week but hopefuly next weekend I'll try it with three cotton threads for the inner. I want to make the powder coating on the strings as large as possible so I will experiment with different methods to achiewe this, possibly using NC laquer or gum arabic as the binder?

As for NC laquer, of course I wouldn't recomend making the NC, however I did see on the leeds university chem. department website a demonstration for use in schools that involved the teacher having prepared cellulose nitrate, so I am currently in discussion with my chem teacher and lab technician about it. (that probably is enough of that topic!)
Is the cellulose dope nitrated?, although it probably burns just as well the the NC from pingpong balls! However, I just bought a liter of acetone which I don't want to waste!

Thomas

Edited by lord_dranack, 26 January 2004 - 12:38 PM.

[Phoenix]

As far as I am aware, cellulose dope comes in two types. Cellulose nitrate, for die hard traditionalists, and cellulose acetate for those who don't want their model planes to go up in a puff of smoke on contact with a flame. The latter is probably like varnish. It might say on the can, but mine didn't (I guess would say ?highly flammable? because of the solvent). The brand was Irvine, or something similar. It functions fine as a flammable binder, and if you take a chunk of the dried up stuff that collects around the lid and light it, it will burn quite nicely (though not explosively - it is not so completely nitrated as flash cotton like materials). It seems quite thick, and I guess you get quite a lot of ping-pong balls in the 250ml can, which was about ?3.50, I think. When I looked for ping-pong balls, the cheapest I could find them was 50p each (I had seen them for 15p, but that shop closed before I ever wanted them). Also, I don't know if they even make them from NC anymore (though this is just a guess).

Edited by Phoenix, 26 January 2004 - 05:29 PM.

[Stuart]

Have the pictures uploaded for the public to see. It's a mean bit of kit, hat's off for lord_dranack.

http://amateurpyro.port5.com

This address will be my backup site soon and a place to host pics and things people wish hosting.

Stuart

[Richard H]

Does this amazing contraption work?

[pyrotechnist]

Nice machine how does it actually work I get how bits of it do but what way does it spin and that.

[lord_dranack]

Yes it does work!
the two spinners spin in opposite directions. The core is fed in the top. the main purpose of the machine is to coat the core with the cotton thread, which it does very well. I am currently experimenting with things to use as the core. Having just got my passfire sub. the method of making good blackmatch presented there looks promising, as it contains a maximum of bp with a minimum of thread.

The reason for the large blue and yellow pulleys are as I don't have any bearings.

[bernie]

Rube Goldberg would be proud. Very clever indeed.

[The_Djinn]

Lord Dranack,

Not sure if it was on Passfire or elswhere but one of the methods described entails drawing 4 strands of cotton thread moistened whith alchohol through a dry comp and not a slurry. The threads are then externaly bound, in your case by 1 X mechano set with cotton thread which is then coated with NC.

If I recall correctly the reason for using dry comp was related to achieving a more consistant burn rate which I do not understand as I would have thought the consistancy of the formula used had more bearing on this.

Mark

[pyrotechnist]

Sorry but which two spinners do you mean on the machine that big blue gear at the bottom or the top gears were the string enters the machine? Any way what does that blue wheel do and were did you get the materials from do you live in uk by any chance to? Sorry for all the questions but just like to know I really like it good work lord dranack good one.

[BurlHorse]

Stuart,

I am indeed impressed, Pretty cool engineering feat I give you that, I can see it now,

Stuart Fuseworks

Good Job Bud!!

Stay Green,

Bear