On Fri, 14 Dec 2018 09:44:30 -0800 (PST), Its Me
wrote:

it had 4 times the power (specific impulse in newton-seconds) of a military Stinger

===

Are you able to calculate that in advance using knowledge of the
chemistry and rocket geometery, or do you do test firings on the
ground?

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On Friday, December 14, 2018 at 1:15:07 PM UTC-5, wrote:
On Fri, 14 Dec 2018 09:44:30 -0800 (PST), Its Me
wrote:

it had 4 times the power (specific impulse in newton-seconds) of a military Stinger

===

Are you able to calculate that in advance using knowledge of the
chemistry and rocket geometery, or do you do test firings on the
ground?

These are commercially produced motors. You can buy single use motors, or aluminum tubes and end caps, then buy the reload kits that have the propellant, O-rings, nozzles, etc for "building" the motor. They have been tested and are rated for their impulse, usually complete with graphs of how it is delivered (bell curve, big spike then slowly tapering off, etc..).

The motors are sized by the letters of the alphabet. The Low power black powder Estes motors are 1/4 and 1/2-A, A, B, C. The fat ones were D motors. E and F are considered mid power. High power starts at G and up. Each letter is a doubling of impulse range in N/s, like 2-4, 4-8, 8-16, etc... Supposedly the Stinger was in the K range. My cluster was 1 L, 2 J's and 2 I's, putting it into the M range.

Here's one source: https://www.apogeerockets.com/Rocket_Motors/Cesaroni_Propellant_Kits/54mm_Motors

On Friday, December 14, 2018 at 1:34:12 PM UTC-5, Its Me wrote:
On Friday, December 14, 2018 at 1:15:07 PM UTC-5, wrote:
On Fri, 14 Dec 2018 09:44:30 -0800 (PST), Its Me
wrote:

it had 4 times the power (specific impulse in newton-seconds) of a military Stinger

===

Are you able to calculate that in advance using knowledge of the
chemistry and rocket geometery, or do you do test firings on the
ground?

These are commercially produced motors. You can buy single use motors, or aluminum tubes and end caps, then buy the reload kits that have the propellant, O-rings, nozzles, etc for "building" the motor. They have been tested and are rated for their impulse, usually complete with graphs of how it is delivered (bell curve, big spike then slowly tapering off, etc..).

The motors are sized by the letters of the alphabet. The Low power black powder Estes motors are 1/4 and 1/2-A, A, B, C. The fat ones were D motors. E and F are considered mid power. High power starts at G and up. Each letter is a doubling of impulse range in N/s, like 2-4, 4-8, 8-16, etc... Supposedly the Stinger was in the K range. My cluster was 1 L, 2 J's and 2 I's, putting it into the M range.

Here's one source: https://www.apogeerockets.com/Rocket_Motors/Cesaroni_Propellant_Kits/54mm_Motors

Oh, and for a little while I got into building "experimental" motors. That basically consisted of mixing a prepared recipe of chemicals together and casting your own fuel grains. Then you cut them and drilled the center core out, and loaded them into the casing with a nozzle and O-rings. The science of making it work properly had already been worked out.

It's funny, the propellant really isn't dangerous. It's some pretty nasty, poisonous stuff, but once cast and set, you can bang on it with a hammer and it's just rubbery. It's hard to light. It's just that once lit, it's hard to put out and it has it's own source of oxygen. Put it in a tube with the proper sized nozzle, and you have a motor. If the nozzle is too big, you have a blow torch. If the nozzle is too small, you have shrapnel.

On 12/14/2018 1:34 PM, Its Me wrote:
On Friday, December 14, 2018 at 1:15:07 PM UTC-5, wrote:
On Fri, 14 Dec 2018 09:44:30 -0800 (PST), Its Me
wrote:

it had 4 times the power (specific impulse in newton-seconds) of a military Stinger

===

Are you able to calculate that in advance using knowledge of the
chemistry and rocket geometery, or do you do test firings on the
ground?

These are commercially produced motors. You can buy single use motors, or aluminum tubes and end caps, then buy the reload kits that have the propellant, O-rings, nozzles, etc for "building" the motor. They have been tested and are rated for their impulse, usually complete with graphs of how it is delivered (bell curve, big spike then slowly tapering off, etc..).

The motors are sized by the letters of the alphabet. The Low power black powder Estes motors are 1/4 and 1/2-A, A, B, C. The fat ones were D motors. E and F are considered mid power. High power starts at G and up. Each letter is a doubling of impulse range in N/s, like 2-4, 4-8, 8-16, etc... Supposedly the Stinger was in the K range. My cluster was 1 L, 2 J's and 2 I's, putting it into the M range.

Here's one source: https://www.apogeerockets.com/Rocket_Motors/Cesaroni_Propellant_Kits/54mm_Motors



That's cool.

On Fri, 14 Dec 2018 10:48:01 -0800 (PST), Its Me
wrote:

On Friday, December 14, 2018 at 1:34:12 PM UTC-5, Its Me wrote:
On Friday, December 14, 2018 at 1:15:07 PM UTC-5, wrote:
On Fri, 14 Dec 2018 09:44:30 -0800 (PST), Its Me
wrote:

it had 4 times the power (specific impulse in newton-seconds) of a military Stinger

===

Are you able to calculate that in advance using knowledge of the
chemistry and rocket geometery, or do you do test firings on the
ground?

These are commercially produced motors. You can buy single use motors, or aluminum tubes and end caps, then buy the reload kits that have the propellant, O-rings, nozzles, etc for "building" the motor. They have been tested and are rated for their impulse, usually complete with graphs of how it is delivered (bell curve, big spike then slowly tapering off, etc..).

The motors are sized by the letters of the alphabet. The Low power black powder Estes motors are 1/4 and 1/2-A, A, B, C. The fat ones were D motors. E and F are considered mid power. High power starts at G and up. Each letter is a doubling of impulse range in N/s, like 2-4, 4-8, 8-16, etc... Supposedly the Stinger was in the K range. My cluster was 1 L, 2 J's and 2 I's, putting it into the M range.

Here's one source: https://www.apogeerockets.com/Rocket_Motors/Cesaroni_Propellant_Kits/54mm_Motors

Oh, and for a little while I got into building "experimental" motors. That basically consisted of mixing a prepared recipe of chemicals together and casting your own fuel grains. Then you cut them and drilled the center core out, and loaded them into the casing with a nozzle and O-rings. The science of making it work properly had already been worked out.

It's funny, the propellant really isn't dangerous. It's some pretty nasty, poisonous stuff, but once cast and set, you can bang on it with a hammer and it's just rubbery. It's hard to light. It's just that once lit, it's hard to put out and it has it's own source of oxygen. Put it in a tube with the proper sized nozzle, and you have a motor. If the nozzle is too big, you have a blow torch. If the nozzle is too small, you have shrapnel.


===

Interesting, thanks - learn something new every day.

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On Fri, 14 Dec 2018 17:19:14 -0000 (UTC), Bill
wrote:

Its Me wrote:
On Thursday, December 13, 2018 at 3:17:29 PM UTC-5, Tim wrote:
You know civilian space travel is coming...

https://www.cnbc.com/amp/2018/12/13/...-of-space.html

It's not the same thing, but back in the 90's I was into high power
rocketry. During that time frame there were 3 guys that got together and
built an amateur rocket that flew to the edge of space. It was a boosted
dart, which means the bottom part was a big, fat rocket motor and the top
was a skinny but heavy small rocket with no motor. When the lower stage
burns out the upper stage drag separates and keeps going (from inertia)
until gravity does its thing.

They launched it in the Black Rock Desert in Nevada. It had a downward
looking camera with a RF downlink for video and telemetry. It hit mach
3.something, and the dart traveled to a bit over 50 miles. I can't find
it now, but there used to be a video showing the flight. You saw the
earth fall away, and when it hit apogee (arced over), you saw the
curvature of the earth and then tons of stars. Unfortunately, it came in
ballistic and impacted a few miles downrange. Even with a backhoe, they
only recovered a few bits.

The story was it took them over a year to build it, and it cost one of
the guys his marriage.


I always loved rockets. We built a bunch of aluminum tube rockets powered
by zinc- sulfur. We used to fire them at the Albany, CA police range when
no one was around. Probably go to jail these days for doing that.

I played with zinc sulfur rockets too. We started with Crossman
cylinders in Bering Cigar tubes. You could really send one for a ride.
Then we started using longer tubes. A Crossman cylinder is a pretty
good fit an 3/4" copper pipe. Solder alone won't hold but if you shoot
a few screws in there and use the solder for a seal it works ok. The
trick is how far up you cut the "nozzle". Just make sure it is
perfectly square or you will just make a pinwheel.
We also played with fins but shooting them out of a long pipe gets
them fairly well stabilized.
The best solution is still a long stick out the back. ;-).

The real trick is finding someone to sell you zinc powder.
We got it from a plating shop until they would not sell it anymore.

On Fri, 14 Dec 2018 10:48:01 -0800 (PST), Its Me
wrote:

On Friday, December 14, 2018 at 1:34:12 PM UTC-5, Its Me wrote:
On Friday, December 14, 2018 at 1:15:07 PM UTC-5, wrote:
On Fri, 14 Dec 2018 09:44:30 -0800 (PST), Its Me
wrote:

it had 4 times the power (specific impulse in newton-seconds) of a military Stinger

===

Are you able to calculate that in advance using knowledge of the
chemistry and rocket geometery, or do you do test firings on the
ground?

These are commercially produced motors. You can buy single use motors, or aluminum tubes and end caps, then buy the reload kits that have the propellant, O-rings, nozzles, etc for "building" the motor. They have been tested and are rated for their impulse, usually complete with graphs of how it is delivered (bell curve, big spike then slowly tapering off, etc..).

The motors are sized by the letters of the alphabet. The Low power black powder Estes motors are 1/4 and 1/2-A, A, B, C. The fat ones were D motors. E and F are considered mid power. High power starts at G and up. Each letter is a doubling of impulse range in N/s, like 2-4, 4-8, 8-16, etc... Supposedly the Stinger was in the K range. My cluster was 1 L, 2 J's and 2 I's, putting it into the M range.

Here's one source: https://www.apogeerockets.com/Rocket_Motors/Cesaroni_Propellant_Kits/54mm_Motors

Oh, and for a little while I got into building "experimental" motors. That basically consisted of mixing a prepared recipe of chemicals together and casting your own fuel grains. Then you cut them and drilled the center core out, and loaded them into the casing with a nozzle and O-rings. The science of making it work properly had already been worked out.

It's funny, the propellant really isn't dangerous. It's some pretty nasty, poisonous stuff, but once cast and set, you can bang on it with a hammer and it's just rubbery. It's hard to light. It's just that once lit, it's hard to put out and it has it's own source of oxygen. Put it in a tube with the proper sized nozzle, and you have a motor. If the nozzle is too big, you have a blow torch. If the nozzle is too small, you have shrapnel.

That was our process. We found a doweled cell in a destroyed building
that use 1.5" galvanized pipe for the dowel and we chipped out an 8x8
block section 2 blocks high for our test stand.
We had a couple zinc sulfur "bombs" that were totally contained.
When we started playing with potassium chlorate, we blew a hole in our
test stand. I doubt anyone would sell you that stuff now and if they
did an ATF agent would be delivering it.

wrote:
On Fri, 14 Dec 2018 17:19:14 -0000 (UTC), Bill
wrote:

Its Me wrote:
On Thursday, December 13, 2018 at 3:17:29 PM UTC-5, Tim wrote:
You know civilian space travel is coming...

https://www.cnbc.com/amp/2018/12/13/...-of-space.html

It's not the same thing, but back in the 90's I was into high power
rocketry. During that time frame there were 3 guys that got together and
built an amateur rocket that flew to the edge of space. It was a boosted
dart, which means the bottom part was a big, fat rocket motor and the top
was a skinny but heavy small rocket with no motor. When the lower stage
burns out the upper stage drag separates and keeps going (from inertia)
until gravity does its thing.

They launched it in the Black Rock Desert in Nevada. It had a downward
looking camera with a RF downlink for video and telemetry. It hit mach
3.something, and the dart traveled to a bit over 50 miles. I can't find
it now, but there used to be a video showing the flight. You saw the
earth fall away, and when it hit apogee (arced over), you saw the
curvature of the earth and then tons of stars. Unfortunately, it came in
ballistic and impacted a few miles downrange. Even with a backhoe, they
only recovered a few bits.

The story was it took them over a year to build it, and it cost one of
the guys his marriage.


I always loved rockets. We built a bunch of aluminum tube rockets powered
by zinc- sulfur. We used to fire them at the Albany, CA police range when
no one was around. Probably go to jail these days for doing that.

I played with zinc sulfur rockets too. We started with Crossman
cylinders in Bering Cigar tubes. You could really send one for a ride.
Then we started using longer tubes. A Crossman cylinder is a pretty
good fit an 3/4" copper pipe. Solder alone won't hold but if you shoot
a few screws in there and use the solder for a seal it works ok. The
trick is how far up you cut the "nozzle". Just make sure it is
perfectly square or you will just make a pinwheel.
We also played with fins but shooting them out of a long pipe gets
them fairly well stabilized.
The best solution is still a long stick out the back. ;-).

The real trick is finding someone to sell you zinc powder.
We got it from a plating shop until they would not sell it anymore.


Easier to get 60 years ago. We used aluminum tube from a TV antenna for a
lot of them. Had a pair of pliers that had a great shape for necking down
the tube up from the end.

On Sat, 15 Dec 2018 03:36:14 -0000 (UTC), Bill
wrote:

wrote:
On Fri, 14 Dec 2018 17:19:14 -0000 (UTC), Bill
wrote:

Its Me wrote:
On Thursday, December 13, 2018 at 3:17:29 PM UTC-5, Tim wrote:
You know civilian space travel is coming...

https://www.cnbc.com/amp/2018/12/13/...-of-space.html

It's not the same thing, but back in the 90's I was into high power
rocketry. During that time frame there were 3 guys that got together and
built an amateur rocket that flew to the edge of space. It was a boosted
dart, which means the bottom part was a big, fat rocket motor and the top
was a skinny but heavy small rocket with no motor. When the lower stage
burns out the upper stage drag separates and keeps going (from inertia)
until gravity does its thing.

They launched it in the Black Rock Desert in Nevada. It had a downward
looking camera with a RF downlink for video and telemetry. It hit mach
3.something, and the dart traveled to a bit over 50 miles. I can't find
it now, but there used to be a video showing the flight. You saw the
earth fall away, and when it hit apogee (arced over), you saw the
curvature of the earth and then tons of stars. Unfortunately, it came in
ballistic and impacted a few miles downrange. Even with a backhoe, they
only recovered a few bits.

The story was it took them over a year to build it, and it cost one of
the guys his marriage.


I always loved rockets. We built a bunch of aluminum tube rockets powered
by zinc- sulfur. We used to fire them at the Albany, CA police range when
no one was around. Probably go to jail these days for doing that.

I played with zinc sulfur rockets too. We started with Crossman
cylinders in Bering Cigar tubes. You could really send one for a ride.
Then we started using longer tubes. A Crossman cylinder is a pretty
good fit an 3/4" copper pipe. Solder alone won't hold but if you shoot
a few screws in there and use the solder for a seal it works ok. The
trick is how far up you cut the "nozzle". Just make sure it is
perfectly square or you will just make a pinwheel.
We also played with fins but shooting them out of a long pipe gets
them fairly well stabilized.
The best solution is still a long stick out the back. ;-).

The real trick is finding someone to sell you zinc powder.
We got it from a plating shop until they would not sell it anymore.


Easier to get 60 years ago. We used aluminum tube from a TV antenna for a
lot of them. Had a pair of pliers that had a great shape for necking down
the tube up from the end.

We tried the aluminum from cheap lawn chairs and it seemed to burn out
It also had holes in most of it so the only good part was the brace
under the chair and the legs. I never had any luck with trying to form
the venturi. A CO2 cylinder was pretty much perfect and they were easy
to come by. I also had lots of short copper tube scraps I picked up
here and there. If you saw off the top dome, drill out or cut off the
venturi end, space it in the copper tube with 16 or 18 copper wire 120
degrees apart it ends up being a very tight fit, Then sweat it in with
solder and you got something. You can use the dome you cut off as the
nose. Same trick.
Another fuel that is almost as good as zinc/sulfur is sugar and
Potassium Nitrate. It is a little scary caramelizing the mix in a gas
oven but we never had it go up. At around 600 degrees it will pour
like honey, just be sure to preheat your funnel and the rocket body
first.
That stuff goes up pretty good too and the ingredients are a lot
easier to get.