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3D printable Visco fuse machine

3D printer visco fuse machine

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#261 Simoski

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Posted 21 May 2018 - 11:46 PM

As a sieve. You could try also to find a laundry dryer filter.

Check that!

 

Thanks I thought maybe laundry powder will help harden tar... : ) lol



#262 Simoski

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Posted 21 May 2018 - 11:50 PM

Sim,

Keep in mind that commercial fuse powder is 'corned'.  The particles, although somewhat irregular in shape, are closely-sized, and approximately the same dimensions in all axes.  Home-made 'screen granulated' power is VERY irregular in shape.  Those often long, irregular particles can tend to interlock when attempting to get them to flow.

 

Your choice of a finer screen is a good start, but you may also have to add 'active agitation' to the power hopper (sorry, if you did already, I didn't remember).  Even mine had it (for corned powder), in the form of a stirring rod that circulated around the periphery of the hopper.

 

Lloyd

Will guide threads be insufficient?



#263 lloyd

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Posted 22 May 2018 - 05:49 AM

Sim,

I had two 'guide threads' on my commercial machine.  Even using commercial fuse powder, it still required a stirring mechanism.  

 

Threads (by themselves) just tend to 'tunnel' in the continuously more-compacting mass of powder, until the mass doesn't move, and the tunnels are just a thread moving through air.

 

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#264 Svimmer

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Posted 22 May 2018 - 06:46 AM

I havent had any problems at all to get the powder flowing  when using  the powder i granulate with the filter.



#265 lloyd

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Posted 22 May 2018 - 07:56 AM

Well, Stix,

Admittedly, I had a powder funnel that was quite a lot larger in capacity than what you guys are working with on a Visco machine.  Mine held just shy of two pounds of powder, and the powder column was about 11" tall (including the funnel depth at the bottom).

 

Gravity was my enemy there.  You guys may have better luck with the right classification of powder.

 

Lloyd


Edited by lloyd, 22 May 2018 - 07:58 AM.

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#266 Simoski

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Posted 24 May 2018 - 12:06 AM

I will try again this weekend, hopefully by then I'll have the guide thread assembly designed and printed.

 

I saw these fuse comps by Spitfire made in 2015, what do you make of them...

 

 

white falling leaves fuse:

 

KNO3................50

Alu dark............30

sulfur................20

 

(0.5 cm/sec)

 

easy safety fuse:

 

KClO4.............70

Willow C..........25

 

(about 0.8 cm/sec)

 

add +5% fine flake Ti for silver falling leaves fuse.

 

''aggressive'' hot safety fuse:

 

KClO4.....................70

Pot. benzoate.........30

dark al.................... 2

sulfur.......................2

 

(1 cm/sec)

 

add 5% - 7% fine flake Ti for flying fish fuse. Use short lengths. They ''swim'' a lot. 

 

Another safety fuse:

 

KClO4.........................75

C willow......................10

Pot. benzoate.............10

 

(1 cm/sec)

 

Delay fuse (rather fast):

 

Fine grained BP..........75%

Powder willow BP........15%

70/30 KClO4/C.............10%

 

(about 1.5 - 2.5 cm/sec)


Edited by Simoski, 24 May 2018 - 12:08 AM.


#267 lloyd

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Posted 24 May 2018 - 05:05 AM

Eh... Sim, I think I'd leave those alone until I could make good fuse with more-conventional black powder -- typically slightly oxidizer-poor and sulfur-rich.

 

Every one of those except the white falling leaves is basically flash powder or H3, both of which are considerably more explosive and more dangerous than BP.

 

When you get  the machine dialed-in, and are certain of the consistency of fuse it creates, then it might be fun to fool with more exotic formulae.  But like everything in life, pyro things tend go better when you approach experiments incrementally, rather than in great leaps that skip many 'basics'.

 

Lloyd


Edited by lloyd, 24 May 2018 - 05:06 AM.

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#268 Simoski

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Posted 24 May 2018 - 05:08 AM

Yeah lets just get some working fuse first Sir.



#269 MrB

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Posted 24 May 2018 - 12:42 PM

I admit. I would probably run sugar in the machine just to get everything working, and dialed in. Might be messy to granulate, or powder, and clean up after testing, but at least it's not a fire hazard.

#270 Mumbles

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Posted 24 May 2018 - 11:38 PM

BP grains are tumbled with a small amount of graphite to improve the flow properties (amongst other reasons) for reloading.  Do you think it would interfere with fuse making?  


Just so you guys quit asking, here is the link to the old forum. http://www.xsorbit2....forum/index.cgi

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#271 Arthur

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Posted 24 May 2018 - 11:52 PM

In the scheme of naming the f's are fineness and the a is for granulated powder and the g is for graphite glazed. Does any literature say whether glazed or plain powder was used in history?



#272 lloyd

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Posted 25 May 2018 - 05:53 AM

Arthur, those are 'said' to be the meanings, but they are not.

 

'A' powder (capital 'A') is blasting powder.  'g' powder (lower-case 'g') is shooting powder.  Not all 'g' powders are graphite-glazed.

 

The story has it that when Dutch traders were plying the African trade, the Africans thought more-highly of polished powder than of dull-looking, so they began to graphite-glaze for that market.  But most powder sold then and much even now is not graphited, merely 'tumble polished'.

 

The two types of powder come in two entirely-different grain-size regimes, and conventionally are also named according to two different methods, so as not to be easily confused.

 

Blasting powders usually are named by an arabic numeral, followed by uppercase "FA".  So "2FA, 4FA", etc.

Shooting powders are usually named by a number of upper or lower-case Fs, followed by a lower-case 'g'.  So, FFFg or fffg.

 

'Hope that helps.

 

Lloyd


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#273 WSM

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Posted 07 October 2018 - 06:16 AM

I admit. I would probably run sugar in the machine just to get everything working, and dialed in. Might be messy to granulate, or powder, and clean up after testing, but at least it's not a fire hazard.



Or, you could run it with 80 mesh charcoal to see how it works. If it's too light and fluffy to replicate BP, add powdered clay to the charcoal and try that.

I'm guessing this will work without gumming up the system.

Good luck.

WSM B)

Edited by WSM, 07 October 2018 - 06:18 AM.


#274 FlipperFuego

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Posted 07 August 2019 - 11:44 AM

Super interesting thread, thanks fro sharing! SmQTeHNsQ9.png



#275 markx

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Posted 08 August 2019 - 10:51 AM

Using a "surrogate" filler to tune in the machine might not be very successful.....at least concerning the parameters of the actual fuse (uniformity, appearance, dimensions, etc.). It is ok to check the functionality of machine related parameters though. Wether everything runs smooth and reliably from the mechanical/electrical side. 

I've messed around with fuse making for quite a while and from the little gathered experience I can tell that changing the formulation and especially the preparation process for the formulation can have immence impact on how the machine and the final product perform. So there really seems to be no "fit all" type of tune for a visco machine. Usually making a change to the composition or the preparation procedure of the filler material shall trigger the need to also make adjustments to the machine (changing the speeds and ratios of gearing, number or type of threads, tension of threads) to achieve the best possible outcome.

Hence using a surrogate filling is likely going to tune your setup to produce the respective surrogate fuse....but assuming the final composition is close enough in density, granulation and geometry of the particles, one may end up with a more or less functional result :) 

Also a word of warning regarding granulated filler compositions: they tend to self seggregate in the funnel if the particle size distribution is not uniform. The coarsest particles (agglomerates e.g. ) tend to gather at the top of the feed funnel and exit last into the fuse. Hence the length of fuse produced from nonuniformly sized particles tends to have a systematic increase of filler particle size along it's length from the finest filler at the beginning and ending with the largest "lumps" at the tail portion. Accordingly the burning speed shall have a systematic growth along the length of the fuse with the fastest part being the tail portion of the produced fuse that contains the coarsest filler. This difference in burn speed can be monstrous....I've had batches where the nose end of the fuse burns at expected rate and the tail part basically explodes instantaneously along the length. So I've accustomed myself to test from the nose and tail part of every produced bundle to see if there is a detectable difference in burn speed and immediately discard the faster burning tail portions. No good to leave lying around to forget about their flaw and then end up with an unpleasant surprise. 





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