Spoolette Tools

[DaMounty]

Hi,

 

Anyone wish to share there experience on homemade spoolette tooling?

 

Thanks in advance

 

...DaM

[nater]

I used a simple metal rod for a long time. Increment lines milled in are nice, but not necessary. Spolette tooling does not need to be complicated. A rod to use as a rammer, a suitable ramming base and some means to control the timing. I drill mine back to be precise, but you can work with your increment sizes carefully so increment is 1/4" of timing.

[lloyd]

Yeah.

 

A 'simple metal rod' does not make as reliable a spolette as a rammer that has a conical tip. Review Pyrotechnica IX and XI for information on that.

 

L

[Mumbles]

I press all my spolettes with an arbor press, so my info is based on that. Wood doesn't work very well for the rammer. The sizes are too small for the force required. I tend to use aluminum since it's easier to cut than stainless steel. The hardest part is getting a flat cut if you don't have a power saw or miter box that will accept a hacksaw. I tended to select a piece that looked pretty flat at the store, and just use the supplied finished end for the side that contacts the BP.

 

I started with just sharpy graduations, but those don't really last long. I eventually put knicks into the side of the ram with a file, but that still isn't all that accurate. Something I've been reading about lately, which might work here is electro etching in the graduations or labels. It should be easy enough to get accurate distances and lines with an exacto knife and caliper/ruler. Drilling back is still basically required if you care about precision timing though.

 

With the tubes from Hobby Horse (from NEPT), I've never really needed to use a support. I occasionally use the 1/4" red spiral tubes for smaller spolettes for smaller shells and inserts. I had some really good ones that I could get away with no support for a while, but that company went out of business. The currently available ones probably need a support of some sort. If you are using something else or just find you need or want a support they're pretty simple. If you can find a metal or stout plastic pipe that will fit snugly, that is probably the easiest option. Alternatively, you can make a "ramming block". I attached a notated image from Fulcanelli. It took me a while to realize that it's the spolette tube on the image, not a pipe or other support. I apparently never bothered to read the paragraph that describes it, or look at the caption very closely. Fulcanelli recommends selecting a thick piece of metal (at least 1") and drilling a hole in it. That wasn't an option for me. I've used a 2x4 before. It's not ideal, and it kind of mars up the outer surface, but it might be an option. I suppose you could use a better drill bit or better wood and get a smoother surface and better product.

 

 

One often over looked thing is a smooth and solid ramming or pressing plate. The arbor press usually has one built in, which is nice. If you're using something else, find a scrap piece of metal to make the spolettes on. If you are ramming find a solid base to ram on. Chunks of log or a post will work in a pinch. Any table light enough that you can move will not. That's experience talking.

[schroedinger]

If you are ramming instead of pressing a wooden dowel will work good.

 

For timing get a plate with a small hole drilled in and 4 threadec rods on the cornes and some nzts to adjust the hight. Now place the spolette under the hole, take a hand cranced drill and drill the spolette back. This way you get equal timing on all spolettes done in one run and only need to measure once per setting.

 

For marking timing steps, cut shrink tubing of equal lenghts and put 'em over the rammer. It should allready sit tight. Now shrink ut a litzle over steam to set them watertight. The tip get's dipped into some wax. Now take some HCl or NaOH solution (10%) and suspend the rammer for 2-3 minutes. Flush it, and look if the marking is deep enough. If yes remove the shrink tubing and polish the rammer, else etch again. The etching happens at the non covered positions.

[lloyd]

Exactly why does one need to mark the rammer for increment sizes? MEASURE your powder! If an increment is a bit small, it makes not a whit of difference. It's only when they're too large that the powder may not be properly-compacted at the bottom of the increment.

 

Save yourselves a LOT of fuss and bother. Just make up a "one increment" powder scoop (say, from a small cap-plug and a piece of dowel for a handle), and press every increment to the same pressure.

 

Again (and this is important), smaller increments don't harm the function or change the timing one bit.

 

For many 'traditional' builders, all spolettes are pressed full-length, then "drilled back" to the correct timing.

 

Contrary to some advice that's been offered, do NOT drill them with a hand-held drill. Either use a drill press with a positive stop, or don't bother!

 

Lloyd

Edited December 10, 2015 by lloyd

[Nessalco]

I'm wondering if waxing the spolette tubes would minimize the effect of humidity and temperature changes when they are stored.

 

Kevin

[nater]

Lloyd, I certainly won't argue about a conical tip for the long run or heavy use. I do think a flat rammer works for someone asking about a quick homemade rammer.

 

I found a marked rammer to be useful to measure the powder column before making a jig to hold spolettes in my drill press. It made for a quick way to eyeball the timing. It worked good to get the cylinder shell bug with single color, single break shells.

 

Now I drill all my spolettes back with a 1/8" brad point bit in a drill press with the stop set for my desired timing. When making several spolettes for a multibreak, you will appreciate the efficiency and precision this way.

[MrB]

Contrary to some advice that's been offered, do NOT drill them with a hand-held drill. Either use a drill press with a positive stop, or don't bother!

 

Hand-drilling is common practice since friction and heat isn't exactly a wanted "item" when working with BP or similar substances. But since drilling back the spoolette is more about timing precision, then trying to create loads of thrust from, say, a powder core, the precision in hand-drilling, or rather, the lack of, would very well be an issue. Now, i have a tangent question.What makes drilling better then making it the right length to start with? We all know the flat surface from the "face" of the spoolette needs prime to reliably catch fire. The few times i do use a spoolette i use a somewhat pointy rammer, and press it with known pressures, to anywhere between half, to two thirds of the spoolette tubes length. (If this doesn't correspond to my timing needs, i'm using the wrong tube, and start over) The tube inside then gets a partway down coating of woodglue (PVA?) and gets filled with BP granules. It's then set aside to dry. When it's dry i simply pour out the BP that hasn't stuck to the walls of the tube, and stick a pair of (home made) blackmatch strands down as far as they can go. Over elaborate, and if i had reliable access to quality black match i would use that, and only that instead, but this has provided me with near perfect reliability. Using equal amounts of composition, and pressing with a known pressure, the finished products give me burn-times that is close enough in time to each other that i cant distinguish a difference between them. If there is an issue, it's the "other" end, the face, where i sometimes struggle to make it reliably catch, and pass fire in to the core of the spoolette. They always catch fire, but sometimes scoring, and double dipping in NC/BP slurry, then BP granules doesn't exactly produce identical burn through times. And if the prime delays the spoolette, then the spoolette will be late, no matter what i do... Pokin a hole in the center seams to work pretty well, but...

 

Anyway, my method works for me currently, but i wanted to ask what theory makes drilling superior to just getting it right from the get go.

Drilling for sure means you get the same length every time, but that says nothing about the density of the composition, and if it had a section that was rammed harder, then the counterpart spoolettes, your still going to be of a tad on that one.

 

And final stupid question. I've been using a fairly pointy rammer. My reasoning for this was simply to create a more energetic, and longer phase when the spoolette spits fire to engage the BM, but from what you guys are saying a part of the reason is / should be to even out the burn-rate differentials from spikes in ramming pressure?

 

Yes, there is no end to my stupidity, and i'm not afraid to ask questions. They say thats how you learn shit, but i'm not sure if it's actually working.

B!

[lloyd]

"...Anyway, my method works for me currently, but i wanted to ask what theory makes drilling superior to just getting it right from the get go.

Drilling for sure means you get the same length every time, but that says nothing about the density of the composition, and if it had a section that was rammed harder, then the counterpart spoolettes, your still going to be of a tad on that one.

 

And final stupid question. I've been using a fairly pointy rammer. My reasoning for this was simply to create a more energetic, and longer phase when the spoolette spits fire to engage the BM, but from what you guys are saying a part of the reason is / should be to even out the burn-rate differentials from spikes in ramming pressure?..."

-----------------------------

 

For the first thing... EVERY spolette should be drilled-back a little. It prevents that dreaded "blow-back", where the fire ends up spitting the wrong way, and _can_ ( I say can, not always will) fail to ignite the passfire match and the burst.

 

In commercial production, most of us find it's more expedient to make them all the same length, then drill them back to the desired time. (And a decent drill press can be made to run slowly enough so that the heat generated by drilling isn't an issue) But since you must (well, should) drill them all back some, even pressing them to the 'right' over-length will involve the same step.

 

There's NO reason why the pressing force should vary (nor the increment size) from increment-to-increment. If you don't have hydraulics or air pressure operated equipment, consider putting a click-stop torque wrench in place of the press's rigid handle instead of just guessing at the force.

 

The conical tip helps convey fire uniformly from increment to increment. It's not intended as a replacement for uniform pressing force.

 

Lloyd

[MrB]

First of, thank you for taking the time to respond.

 

 

 

For the first thing... EVERY spolette should be drilled-back a little. It prevents that dreaded "blow-back", where the fire ends up spitting the wrong way, and _can_ ( I say can, not always will) fail to ignite the passfire match and the burst.

 

Isn't this achieved with the conical shape of the rammer? It leaves an indentation in the open end, where the fire will eat its way in to the bottom and then rapidly shoot up the sides of the indentation. Thats my primitive understanding of it, and the only reason i started using this style of rammer in the first place. Drilling it back would of course create more of the same effect, that is, if you drill it deeper. (Odds are, you do.)

 

In commercial production, most of us find it's more expedient to make them all the same length, then drill them back to the desired time. (And a decent drill press can be made to run slowly enough so that the heat generated by drilling isn't an issue) But since you must (well, should) drill them all back some, even pressing them to the 'right' over-length will involve the same step.

 

In commercial production i can very well see why you would start out with a standardized size, and then adapt it. It makes a lot more sense then trying to stock every delay you would ever need. Since your always drilling them back it makes even more sense. I'm going to have to go on faith, and say that i will try it out. But that raises the question... Using metrics, i use 6mm tooling, and roughly 3mm walled tubes. (I say roughly, since i roll them my self. Internal diameter is easy, external... Well, that varies a little. +0-,3mm or so.) What size drillbit, and how deep, would a suggested minimum be?

Truth be told, i think the variance in delay i have is much more from the "other" end, where my prime simply takes to long to burn through, and ignite the core it self.

 

 

There's NO reason why the pressing force should vary (nor the increment size) from increment-to-increment. If you don't have hydraulics or air pressure operated equipment, consider putting a click-stop torque wrench in place of the press's rigid handle instead of just guessing at the force.

 

I sort of cheat. I use a more or less fully equipped truck-workshop during downtime, for my pyro, so i have access to, and use a hydraulic press with a oil-pressure gage. As i mentioned before whenever i do press a few out for a project, they are very consistent. I haven't got a freaking clue what the pressure conversion table looks like, i simply break a few tubes, note the pressure, and use about 10% less for the projects. Since my tubes are not exactly perfect to start with, i always have a bunch that can be... sacrificed for this purpose, from each batch. The good tubes probably could take a little more, but this leaves me with a good safety margin.

 

The conical tip helps convey fire uniformly from increment to increment. It's not intended as a replacement for uniform pressing force.

 

Interesting. What your really saying is that the smooth surface between increments slows down the burn, creating variances in how fast the burn propagates through the tube? Or was that something i came up with out of some weird misunderstanding?

I'm thinking outside this particular use, and more along candles and end-burners. Most my tooling is flat-ended, which at this point seams like a poor design choice.

Anyway, i'm sort of getting way of topic here. Thank you for putting up with the daft questions.

B!

[lloyd]

Truth be told, i think the variance in delay i have is much more from the "other" end, where my prime simply takes to long to burn through, and ignite the core it self.

-------------

Hmmmm... The conventional way is to tie several strands of bare match over the SCRATCHED take-fire end. Priming can, indeed, vary in the time it takes to burn through to the spolette's core.

 

The conical tip on the press-rod is to gain surface area in that portion of each increment's joining to the next. It has the effects of 1) ensuring cracks don't form between increments, and 2) causing two adjacent increments to be involved in the fire simultaneously, when the flame front is passing a 'joint'.

 

RARELY, flat-ended increments have been known to stop-fire at the unions. This is just a simple way of preventing that from ever happening.

 

LLoyd

[MrB]

Hmmmm... The conventional way is to tie several strands of bare match over the SCRATCHED take-fire end. Priming can, indeed, vary in the time it takes to burn through to the spolette's core.

 

Yeah, i know. It's both hard to find quality stranded BM (QM really) and get it shipped to Sweden, so for the time being i'm working with alternatives where ever i can.double dipping, and poking a hole exposing the core gets it to where the variances are quite small, but it wouldn't be good enough for timed reports, or something similar, that just has to go of simultaneously.

 

The conical tip on the press-rod is to gain surface area in that portion of each increment's joining to the next. It has the effects of 1) ensuring cracks don't form between increments, and 2) causing two adjacent increments to be involved in the fire simultaneously, when the flame front is passing a 'joint'.

 

RARELY, flat-ended increments have been known to stop-fire at the unions. This is just a simple way of preventing that from ever happening.

 

Never knew that to be an issue, but hopefully now it never will be either.

I think my rammer is pointy enough for more then 2 layers even, so perhaps overdoing it a bit. (I know i am. I always split the tube at the point of the rammer, not further down, which indicates that the force to the sides is a bit extreme. But i designed it in that way from the start to produce the fire "spitting" i wanted, so it has been a drawback i was willing to work around. If i ever redesign, i might go with a pointier point, and then round it out towards the edge, almost going flat. It should also let me start with a smaller amount of powder for the first increment.

 

All right. Thanks for sharing. I hope i didn't sidetrack the thread so much that everyone else was unable to gain something from it.

B!

[lloyd]

The point really shouldn't be more than about 90-degree included angle. Even 120-degrees will work fine.

 

If it's too 'pointy', the tendency is to push the powder OUTWARD, rather than compacting downward uniformly. This unduly distorts the tube and causes inconsistencies in the compaction (because the powder 'grabs' the tube).

 

All you want is 'enough' tip-taper.

 

Some folks even 'shoulder' the tip a little to ensure compaction at the sidewalls, but the 'push-out' effect is still there, if the taper is too thin.

 

Lloyd

Edited December 11, 2015 by lloyd

[dynomike1]

I use a small tubing cutter to cut my tubes. I just put a wooden dowel in them and cut them. I also had trouble with delayed ignition. Now i use 1-2 strips of BM depends on tube size) on one side of the spoolette and a thin prime on the other side, now timing is on the money. Yall might be right on the wooden dowels, but that is all i have ever used with no problems. Right now i am pressing serpents with whistle fuel.

[schroedinger]

Actually i have to say that i never primed a spoolette on the outside and never had problems with ignition. Just scratch it and good. On the inside it was the same, without driling back. But i started to use black match on the inside in my 2nd year of building., just to be sure.

[lloyd]

I'm going to ask a purely rhetorical question:

 

If you've put 4-5 hours into building a shell, what 'savings' do you really gain by skipping steps that might add two or three minutes to its construction?

 

Hmmmm?

 

I use every "safety measure" I can. They add virtually no time to the build (et al, maybe a half-hour), but sure do reduce the disappointments when that five hours' worth of work hits the ground in one piece! <G>

 

Lloyd

[schroedinger]

Maybe i should have mentioned, that my sxperience with spolettes is limited to bottom fused shells, with top fused shells i would ofc bother with the top hat method (Always used TF in those).

[MrB]

If it's too 'pointy', the tendency is to push the powder OUTWARD, rather than compacting downward uniformly. This unduly distorts the tube and causes inconsistencies in the compaction (because the powder 'grabs' the tube).

 

This is what i got right now. And i'm, as an estimate, a bit pointier then 90 degrees. Not a whole lot, but a bit.

 

Some folks even 'shoulder' the tip a little to ensure compaction at the sidewalls, but the 'push-out' effect is still there, if the taper is too thin.

 

Thats what i was thinking of, if i was to make a new rammer.

 

I'm going to ask a purely rhetorical question:

 

If you've put 4-5 hours into building a shell, what 'savings' do you really gain by skipping steps that might add two or three minutes to its construction?

 

For me it's about a hobby. It's never about saving time, but all about making it work with the limitations put in place by what supplies i can get hold of.

 

B!

[Fulmen]

Some folks even 'shoulder' the tip a little to ensure compaction at the sidewalls,

 

What about a stepped cylindrical end? This should provide overlap while keeping outwards pressure to a minimum.

[lloyd]

Stepping the end might cause the tiny bit down inside the cylindrical cavity not to be fully compressed, causing a 'quick spot'.

 

I've never tried it, and thus I cannot tell you exactly what might or might not happen. I don't see any advantage of that style over a plain conical tip.

 

Perhaps you do see advantages. If so, what might they be?

 

LLoyd

[Fulmen]

The thought was that it might produce less pressure on the tube, but I do see your reservations. I'd really like to avoid sleeves, with hand-rolled tubes it's hard to get the OD consistent enough. And I don't really like more confinement than I absolutely need, just in case something goes wrong. Guess I'll have to try out a few different variants and see what happens. A shallow cone with a flat shoulder sounds like a good place to start.

 

Luckily the tooling is the least of my problems, I got the lathe and mill safely home today so the new shop will be up and running soon enough.

[mikeee]

The thought was that it might produce less pressure on the tube, but I do see your reservations. I'd really like to avoid sleeves, with hand-rolled tubes it's hard to get the OD consistent enough. And I don't really like more confinement than I absolutely need, just in case something goes wrong. Guess I'll have to try out a few different variants and see what happens. A shallow cone with a flat shoulder sounds like a good place to start.

 

Luckily the tooling is the least of my problems, I got the lathe and mill safely home today so the new shop will be up and running soon enough.

 

Fulmen,

 

Post a photo once you get the equipment up and running, always fun to see new tools going to work!

[Fulmen]

I'll see what I can do. It's not exactly spacious, about 10m^2 but it's enough for a 12x30 lathe and a bridgeport mill.

[mikeee]

With a mill and a lathe you can build just about anything, enjoy!