Pseudo Direct Staging W/Composites

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jqavins

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This is a little outside the box, and feel free to tell me that I'm all wet.

I know well the reason that direct staging doesn't work with composites, and since it doesn't there's no reason for SU composites to come as -0 booster engines. But can a composite's ejection charge light a BP motor? Use the shortest delay available and have a little coast time before lighting a BP sustainer. Has this been tried? Does it work?

Then there's the other side of the coin. Would it be allowed to place a fast burning, high temperature fuse in a composite motor, such that the ignition (or ejection) charge below lights the fuse, which burns all the way up the core and lights the motor. I don't know if a suitable fuse exists, but I don't see why one couldn't. If one does, would there be any reason not to use it? Has this been tried? Does it work?
 

SharkWhisperer

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Joseph, please filter past the beginning of the "Low power; no ejection charge" thread a few below this one for some ideas. In my opinion, this would be simples, but we cannot discuss specific formulas on the public forum. I have often performed fuse-based fire transfer but not yet to a composite recipient. I really cannot envision that getting a nice hot flame far up the recipient motor core, with whatever desired timing, would pose any problem at all. Easy stuff...
 

jqavins

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I will look. I understand not discussing the chemistry here in the open forum. I hadn't mean to ask about that (for now) but rather about the concept in general.

Actually, the first topic in the OP is of more immediate interest to me; can I use a composite's ejection charge to light a BP engine? I have a slightly overweight two stage design half built. A B14-0 would lift it off the rod fast enough, but of course those are not around anymore. There are two Q-Jets (C18 and D20) that would work IF the staging to a BP A, B, or C engine will work.
 

heada

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There was a discussion on another forum where someone drilled a Q-Jet to less than the 4 second delay to get near zero delay (not recommended) and then used thermalite to start the second stage (thermalite is virtually impossible to obtain now) so staging 18mm composite to 18mm composite directly is theoretically possible.
 

jqavins

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Joseph, please filter past the beginning of the "Low power; no ejection charge" thread a few below this one for some ideas...
OK, I read over in the other thread, and I see that your first very long and very informative post covers both of my topics. Thank you. I'll read in more detail later, as I think I'd better do something of value to my employer now.
There was a discussion on another forum where someone drilled a Q-Jet to less than the 4 second delay to get near zero delay (not recommended)...
I fly almost exclusively at club launches, so I will not be adjusting the delays in Q-Jet motors. I just need to make sure that the 4 second delay is short enough that I still have what would be safe rod exit speed when the four second delay is up.
 

SharkWhisperer

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I will look. I understand not discussing the chemistry here in the open forum. I hadn't mean to ask about that (for now) but rather about the concept in general.

Actually, the first topic in the OP is of more immediate interest to me; can I use a composite's ejection charge to light a BP engine? I have a slightly overweight two stage design half built. A B14-0 would lift it off the rod fast enough, but of course those are not around anymore. There are two Q-Jets (C18 and D20) that would work IF the staging to a BP A, B, or C engine will work.
Boosting with composite and transfering fire to a BP second-stage motor? This would be simple to accomplish and just as easy to set desired timing. It would involve removing any ejection charge (seen Aerotech videos showing this) but no modification of delay grain. Would also probably benefit from pyrogen/fuse-enhanced flame transfer (unsure how much fire the Q-Jet delays produce alone). But definitely doable with minimal effort and materials.
 

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If using a Q-Jet, to transfer fire to a BP motor, Id recommend removing the vinyl plug and cutting the ejection charge down a good bit. I don't think that removing the ejection charge entirely will provide a reliable ignition from the Q to the Estes motor because the delay grain isn't nearly as "flame producing" as the end of an Estes BP-0 motor. The Estes -0 motors have a blackpowder based delay grain and the Qs use a composite based delay grain. Thats why I think it won't quite have enough fire and spark propelled forward to ignite the BP motor. Thats why I recommend using something as a pass-fire to the BP motor. Options include leaving some of the BP ejection charge in there and plugging with a bit of tissue, using a bit more of some BP substitute(pyrodex) since it burns similarly to bp but a bit slower, or a blackpowder based fuse(blackmatch) going from one to the other. That last option is a carry over from my pyrotechnic days and I'd say if you don't already know how to make really good black match, you'd be much better off going with option one or two. All of that being said, I'd make sure to not use the vinyl plug that comes with the Q jets to keep the powder in. I'd either use a little ball of tissue and a small piece of masking tape or something similar. It may not make a difference, but just in case that vinyl plug would be able to block the fire and sparks from reaching the BP motor, you want to give yourself every chance of success.
 

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anybody know what the ignition temperature is of composite versus BP motors.....that might help in deciding what pyrogen to use.....DeepOvertone has described what I've been thinking about doing......

over in Ye Old Rocket Forum, I described a technique to drill a hole down the center of the delay train, then put in place a small diameter tube with a fast burning composite delay train material in it....like warp9 or similar....you paint the top of this composite mini delay train tube with pyrogen and it should burn hot enough to ignite not only BP but composites too..... the idea is you have a regular or slow delay and a fast delay going at the same time.....the fast delay will ignite the upper motor at the time of the lower motor burnout.....in this you wouldn't necessarily need BP as an ejection charge in the lower motor, the FAI guys have used flash paper/cotton to gap stage far apart BP motors, the substances might work here if confined....flash paper and cotton is just dipped in nitrocellulose and allowed to air dry...

as soon as I get access to a launch site, I'm going to test out some of these ideas on captive motors attached to a launch pad, where I can record in slo-mo and watch what happens.....
 

DeepOvertone

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anybody know what the ignition temperature is of composite versus BP motors.....that might help in deciding what pyrogen to use.....DeepOvertone has described what I've been thinking about doing......
Its not only the ignition temperature of the composite propellant but having that heat there LONG enough. Even igniters designed to light composite propellant sometimes fails to do so. As you know the composite motors are designed to be lit from the top down so fuses are a no go. I read your idea about a tube containing a fast delay.. The main issue I see is sealing said tube inside of the booster motor such that no fire from the burning motor can bypass it and cause loss of pressure inside the motor(and many other problems). Could it possible be made to work with lots of trial and error? Yeah, maybe so. But many other reliable ways of staging composites have already been proven. No need to re-invent the wheel here.
 

shockie

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Its not only the ignition temperature of the composite propellant but having that heat there LONG enough. Even igniters designed to light composite propellant sometimes fails to do so. As you know the composite motors are designed to be lit from the top down so fuses are a no go. I read your idea about a tube containing a fast delay.. The main issue I see is sealing said tube inside of the booster motor such that no fire from the burning motor can bypass it and cause loss of pressure inside the motor(and many other problems). Could it possible be made to work with lots of trial and error? Yeah, maybe so. But many other reliable ways of staging composites have already been proven. No need to re-invent the wheel here.
Hey DeepOverTone......what are the other methods of reliably staging composites, besides electronic means? Any online resources? magazine articles? I've read Jay Calverts R&D report . I also found out the BP motors ignite at 550F . I would assume that the ignition temperature/time for the various composite propellant types would vary.
 

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i fly very few composite motors, so don’t have the inside poop on the ejection charges.

i do a good bit of BP to BP gap staging. This is ALWAYS done with zero delay motors, and the burnout of a zero delay BP motor is significantly different from delay type (standard) BP motors.

great article here



key point being that the “Hot Blowing Chunks” theory of gap staging (which actually is how it is described in Stine’s book) is incorrect. zero delay motors have no clay cap. The forward edge is simply the end of the BP propellant. When they burn through, EVERYTHING burns and there are no junks, just radiant hot gas. In a ways this makes sense, as the cone of the sustainer nozzle is a “cul de sac”, there is no air flow through it, so it is hard to get “chunks” that are small enough to fit in the nozzle but have enough kinetic energy to push the air out of the way and make it to the propellant at the nozzle apex. Hot photons have no such limitation.

from my balsa Helis with tubeless motor mounts, which fly on standard clap capped BP MOTORS, I occasionally see small scorch marks WELL forward of the motor, and most rocketeers have seen chutes or streamers where there are LOCALIZED scorch marks or holes from hot chunks from clay capped motors, when you didn’t use enough wadding. Other situations where the whole rear end of loaded chute melts seen when you really skimped on the wadding is more likely due to exposure to hot gas.

in any case, does the ejection charge of a BP motor act more like a zero delay BP motor (pure hot gase/flame) vs the mixed clay and hot burning propellant chunks of a standard clay capped BP motor? If the latter, even if you CAN get around the delay issues of trying to use composite booster and BP staging, it may not work well.
 

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Black powder produces about 40% gas and 60% solids.

BP produces its gas much more rapidly resulting in a larger initial pressure pulse. This can blow the model off a position piston or separate a staged rocket if it is
not securely attached to the piston or staged rocket. (the so-called Barber delay) . In other words, there is a pressure pulse and then a pressure decline. Typical BP behavior has been known for decades.

BP burn rate can be controlled by grain size (FG is larger than FFFFg and therefore burns slower) and
whether or not it is a grandular powder versus being a pressed product. A pressed BP product would be slower than
non-pressed product.

the release of energy from Black Powder is a multi-step process,
first from the burning of the grains,
next from the latent heat release from condensation,
and finally from the latent heat release from fusion.

Has anybody seen the dozens of Youtube videos where it shows the ejections charges firing? It looks just like a propellant plume . Unfortunately all the videos are of motors with delay trains, none without for comparison. There is a difference between a -0 pressed BP motor and a -x delay time motor. Both can be used to ignite an upper stage. The difference between the two, other than one has a delay element and a BP ejection charge enclosed by a clay cap is the -0 motors have pressed BP while the -x delay motors have granular BP on top of the delay train.

what would be interesting to see is how the ejection charge plume varies with -0 versus those motors with a delay train.

I would like to see this experiment replicated with an infrared camera . I don't know if consumer-level infrared cameras would be able see fine particle solids.




what we need is the above video with a -0 engine.... in the above you can clearly see flaming particulates being ejected




I found it interesting the 13 and 18mm motors actually had what I would call a burn-thru while the 24 mm D12 had a more explosive burnthru..... This might be because they press D12 differently than 13/18mm and the top layer of BP being pressed was lighter. to I might be the diameter

In the 1965 1st edition of the Handbook of Model Rocketry, GHS states: "the hot combustion gases from the lower-stage engine have broken thru the thin remaining disc of the lower-stage engine propellant. These HOT GASES blast forward up the lower-stage body tube and pass up the nozzle of the upper-stage engines, thereby igniting it. "

even Estes Industries' Vern Estes stated in TR-2(1963) "that hot gases and small pieces of burning propellant......."
 
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MClark

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Back in the 80’s early 90’s Aerotech made 0 delay composite motors. They were more like a 1 or 2. We used sheathed thermalite fuse, burns fast and hot, to get fire to the head of second stage composite motor.
Another method was again sheathed thermalite but ignited by exhaust of first stage. End of fuse has masking tape on it to prevent a chuff from lighting it. By doing this the motor ejection can be used for recovery. Motors without a 0 delay can be used.

Here is a picture of the second method. I357 to I65. Sheathed fuse is just taped to outside of booster.

EZI-BO~1r.JPG
 

ksaves2

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Back in the 80’s early 90’s Aerotech made 0 delay composite motors. They were more like a 1 or 2. We used sheathed thermalite fuse, burns fast and hot, to get fire to the head of second stage composite motor.
Another method was again sheathed thermalite but ignited by exhaust of first stage. End of fuse has masking tape on it to prevent a chuff from lighting it. By doing this the motor ejection can be used for recovery. Motors without a 0 delay can be used.

Here is a picture of the second method. I357 to I65. Sheathed fuse is just taped to outside of booster.

EZI-BO~1r.JPG

That is exactly what I was thinking. It could take a "high" energy fuse of some kind to ignite the upper stage. Perhaps a pyrotechnic type of thing that would hit a chunk/bit of APCP to ignite the upper grain of a motor. Looks like Mark has done it or seen it done. Kurt Savegnago
 

MClark

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The thermalite for ignitors was the most common used "back in the day". Usually without a propellant booster charge. Prior to the mid to late 90’s there was very few electronics available, had to use what we could find.
Picture is my rocket. HP Rockets staged with fuse I would guess I have done 40-50 times.
It is really quite simple to do
 

ksaves2

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The thermalite for ignitors was the most common used "back in the day". Usually without a propellant booster charge. Prior to the mid to late 90’s there was very few electronics available, had to use what we could find.
Picture is my rocket. HP Rockets staged with fuse I would guess I have done 40-50 times.
It is really quite simple to do

Ummm,
Just curious. Is "real" thermalite still available? Errrr, ummm. I've made some reasonable facsimiles of when I learned to do research. Recipes are online for the curious.

Kurt
 

MClark

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I have heard it is available in Canada.
There is some old rolls that show up, if stored properly not too hot or cold it’s still good.
None of the homemade stuff works as well as original recipe.
 

SharkWhisperer

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Thermalite?? Of course it's available. Simple. Cheap. Legal, too. Stringent storage condition requirements are ridiculous. The stuff is stable for years. Keep it dry or dry it out. At varying temps. It's a simple inorganic mix and nothing is hygroscopic (atmospheric water attracting). Simple.

I'm rather new posting here, but I have decades in rocketry, and have been poking around the site for some years. I have learned much, thank you all, and am always amenable to sharing knowledge. Though I've followed topics here for many years as a reader, I appreciate the inconvenient dichotomy between fireworkers and rocketeers (actually, there should be none). I tread lightly when discussing hybrid projects, though I have launched hundreds of rockets, with fins, on homemade motors, using homemade BP. Costs me about $2 for an F-impulse motor and pyrogenic igniter (or "initiator", if you agree with the "dumbing down"). It's an igniter, ffs. The NEPT cardboard tube is the costliest item (and easily substituted or manufactured for those on a budget).

I have had fewer CATOs on my D/E/F homemade motors than I have ever had with Estes or Quest branded motors. I have had 3 CATOs on Estes E9s, and 1 CATO on an F15. Don't care about manufacture dates--they're the professionals. I make the same. It takes me 10 minutes to make a motor, when I'm taking my time. After optimization (including CATOs on the ground), I have never yet destroyed a rocket with my own motors. Estes motors have disintegrated a variety of rockets (RIP Big Daddy:).

But "Thermalite" info is basic pyrotechnician knowledge that is neither restricted nor illegal. We cannot discuss specific formulations per site rules, and I have no intention, but these comps are numerous and simple to organize with just a little caution. And about as safe as BP to work with...

SW: Edited for clarity, grammar, and detail.
 
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DrewW

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This is a little outside the box, and feel free to tell me that I'm all wet.

I know well the reason that direct staging doesn't work with composites, and since it doesn't there's no reason for SU composites to come as -0 booster engines. But can a composite's ejection charge light a BP motor? Use the shortest delay available and have a little coast time before lighting a BP sustainer. Has this been tried? Does it work?

Then there's the other side of the coin. Would it be allowed to place a fast burning, high temperature fuse in a composite motor, such that the ignition (or ejection) charge below lights the fuse, which burns all the way up the core and lights the motor. I don't know if a suitable fuse exists, but I don't see why one couldn't. If one does, would there be any reason not to use it? Has this been tried? Does it work?

I’ve been running through NAR publication archives recently and there was an R&D report at NARAM-46 that covered this exact topic by J. Calvert.
 

MClark

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Thermalite?? Of course it's available. Simple. Cheap. Legal, too. Stringent storage condition requirements are ridiculous. The stuff is stable for years. Keep it dry or dry it out. At varying temps. It's a simple inorganic mix and nothing is hygroscopic (atmospheric water attracting). Simple.

I'm rather new posting here, but I have decades in rocketry, and have been poking around the site for some years. I have learned much, thank you all, and am always amenable to sharing knowledge. Though I've followed topics here for many years as a reader, I appreciate the inconvenient dichotomy between fireworkers and rocketeers (actually, there should be none). I tread lightly when discussing hybrid projects, though I have launched hundreds of rockets, with fins, on homemade motors, using homemade BP. Costs me about $2 for an F-impulse motor and pyrogenic igniter (or "initiator", if you agree with the "dumbing down"). It's an igniter, ffs. The NEPT cardboard tube is the costliest item (and easily substituted or manufactured for those on a budget).

I have had fewer CATOs on my D/E/F homemade motors than I have ever had with Estes or Quest branded motors. I have had 3 CATOs on Estes E9s, and 1 CATO on an F15. Don't care about manufacture dates--they're the professionals. I make the same. It takes me 10 minutes to make a motor, when I'm taking my time. After optimization (including CATOs on the ground), I have never yet destroyed a rocket with my own motors. Estes motors have disintegrated a variety of rockets (RIP Big Daddy:).

But "Thermalite" info is basic pyrotechnician knowledge that is neither restricted nor illegal. We cannot discuss specific formulations per site rules, and I have no intention, but these comps are numerous and simple to organize with just a little caution. And about as safe as BP to work with...

SW: Edited for clarity, grammar, and detail.

We are referring to Thermalite the igniter fuse.
Not thermite the metal oxide/reactive metal mixture.

M
 

AeroTech

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That’s basically what I did staging Enerjets back in the day, except using Enerjet wick. But I ignited them both on the ground, separated by a second or so.
Back in the 80’s early 90’s Aerotech made 0 delay composite motors. They were more like a 1 or 2. We used sheathed thermalite fuse, burns fast and hot, to get fire to the head of second stage composite motor.
Another method was again sheathed thermalite but ignited by exhaust of first stage. End of fuse has masking tape on it to prevent a chuff from lighting it. By doing this the motor ejection can be used for recovery. Motors without a 0 delay can be used.

Here is a picture of the second method. I357 to I65. Sheathed fuse is just taped to outside of booster.

EZI-BO~1r.JPG
 

SharkWhisperer

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We are referring to Thermalite the igniter fuse.
Not thermite the metal oxide/reactive metal mixture.

M
I very well know the difference between thermite (of which there are many) and Thermalite, which is simple to reproduce (and modify/improve to serve different tasks). In fireworking, it's sometimes used as a substitute for standard Chicom Time Fuse for timing shell ignition. The composition (all speeds) is simple to reproduce and its formulation is well-known in the pyrotechnic community (and I'm sure by several rocketeers with chemistry foundations).
 
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shockie

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Gary : Can you tell us what the ignition temperature of composite propellant is? Or is that proprietary information? Or does it vary between the various propellant types?
 

shockie

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I’ve been running through NAR publication archives recently and there was an R&D report at NARAM-46 that covered this exact topic by J. Calvert.
Direct Non Electronic Staging from AP to BP Motors, Jay Calvert, NARAM 46 R&D, 2004 it also appeared in a later Sport Rocketry.
 

TALON

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This is a little outside the box, and feel free to tell me that I'm all wet.

I know well the reason that direct staging doesn't work with composites, and since it doesn't there's no reason for SU composites to come as -0 booster engines. But can a composite's ejection charge light a BP motor? Use the shortest delay available and have a little coast time before lighting a BP sustainer. Has this been tried? Does it work?

Then there's the other side of the coin. Would it be allowed to place a fast burning, high temperature fuse in a composite motor, such that the ignition (or ejection) charge below lights the fuse, which burns all the way up the core and lights the motor. I don't know if a suitable fuse exists, but I don't see why one couldn't. If one does, would there be any reason not to use it? Has this been tried? Does it work?

I put on "backyard Firework shows", and I use a fuse that has a burn rate of 1 foot in 0.22 seconds! That is burning One FOOT in ZERO Point 22 seconds!
I am 99% sure that would work in your scenario. Now is it within the NAR code?[/QUOTE]
 

SharkWhisperer

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If you go a few threads down from this one in this Propulsion section to "Low power, no ejection charge?", this specific approach is discussed in detail on page 2.
 
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