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  1. #31
    Join Date
    30th January 2016
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    US > OK > NE
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    2,656
    Quote Originally Posted by dixontj93060 View Post
    Just don't show to the hypersensitive rules people...
    Put it in a casing, widest nozzle there is, presto: it's an EX G2.3 motor ( or whatever ).

    Last edited by dhbarr; 21st July 2017 at 02:39 AM.

  2. #32
    Join Date
    19th January 2009
    Location
    Pine Mountain, Ga
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    1,914
    Quote Originally Posted by dixontj93060 View Post
    Just don't show to the hypersensitive rules people...
    Have you used these before? Wondering how hot they get.

    Christopher Short
    TRA #10247 L3 TAP
    NAR #83000 L3CC
    Prefect #38
    Chris' Rocket Supplies, LLC
    www.csrocketry.com
    sales@csrocketry.com
    850-554-6531

  3. #33
    Join Date
    29th February 2016
    Location
    West Coast of Canada
    Posts
    58
    The flare that was user in the rocket was a black smoke flare from a movie house FX company. If I remember it had a burn time of 50 sec at 70,000 cubic feet worth of ink black smoke!

  4. #34
    Join Date
    20th February 2009
    Location
    Cayuga, Indiana
    Posts
    12,487
    Quote Originally Posted by tbonerocketeer View Post
    Have you used these before? Wondering how hot they get.
    No, not really hot at all and lots of smoke. I'm considering for my 3/4 Scale Nike Smoke nosecone vents. My former son-in-law showed them to me. He works for an HVAC company. They sit the grains inside a exit or return vent and light them to observe the air flow. I posted a 90 second one, but I think they have up to like 3 minutes in duration.
    L3, TRA #11847
    Tripoli Indiana #132
    Tripoli Central Illinois #59
    Central Illinois Aerospace (NAR) #527
    Chicago Rocket Mafia, "Big Bucks" Dixon
    ___________________________________

    Quiet little voices creep into my head. -- We Were Promised Jetpacks

  5. #35
    Join Date
    26th November 2009
    Posts
    4,087
    I simply use the longest delay grain available for the 38's and use electronic deployment. Depending on the flight, I see smoke past apogee. A full size/diameter smoke grain likely is going to heat soak a case possibly damaging it.
    But, if one did like a 54mm diameter grain encased in an insulator for say a 75mm motor, that is workable and I bet folks have already done that with success.
    Ever notice how the commercial smoke delays are put in thick walled cardboard tubes in the forward closures? It's called insulating and I bet that can be applied to larger smoke grains. Kurt

  6. #36
    Join Date
    7th August 2013
    Posts
    274
    Quote Originally Posted by dixontj93060 View Post
    No, not really hot at all and lots of smoke. I'm considering for my 3/4 Scale Nike Smoke nosecone vents. My former son-in-law showed them to me. He works for an HVAC company. They sit the grains inside a exit or return vent and light them to observe the air flow. I posted a 90 second one, but I think they have up to like 3 minutes in duration.
    I tried one in a 38mm motor to get colored smoke, placed in the smoke well, it got consumed during the motor burn, no smoke.
    I plan to try it again , but this time pour a web thickness propellant slug on top of it to insulate it during the motor burn, hoping that will do the trick.
    My homebrew attempts at achieving colored smoke have all failed dismally so far.
    John Haught L3
    VP Tripoli Pittsburgh

  7. #37
    Join Date
    30th January 2016
    Location
    US > OK > NE
    Posts
    2,656
    Quote Originally Posted by ksaves2 View Post
    I simply use the longest delay grain available for the 38's and use electronic deployment. Depending on the flight, I see smoke past apogee. A full size/diameter smoke grain likely is going to heat soak a case possibly damaging it.
    But, if one did like a 54mm diameter grain encased in an insulator for say a 75mm motor, that is workable and I bet folks have already done that with success.
    Ever notice how the commercial smoke delays are put in thick walled cardboard tubes in the forward closures? It's called insulating and I bet that can be applied to larger smoke grains. Kurt
    Most recent Tripoli Report covers just exactly this.

  8. #38
    Join Date
    21st January 2009
    Location
    Glendale, Arizona
    Posts
    1,656
    Quote Originally Posted by sharkbait View Post
    I tried one in a 38mm motor to get colored smoke, placed in the smoke well, it got consumed during the motor burn, no smoke.
    I plan to try it again , but this time pour a web thickness propellant slug on top of it to insulate it during the motor burn, hoping that will do the trick.
    My homebrew attempts at achieving colored smoke have all failed dismally so far.
    Colored smoke, "smoke bombs", are typically a fuel rich sugar chlorate mix with dyes added to give color. In operation the sugar chlorate vaporizes the dye and it cools and condenses into very small particles. Issues are if to hot the organic dye decomposes giving no color, and if it comes out of the container too hot it can ignite and burn in the air.
    If used in a rocket motor the burn rate under pressure of chlorate mixes is to high and grain is consumed before propellant grains.

    M

  9. #39
    Join Date
    26th November 2009
    Posts
    4,087
    Quote Originally Posted by MClark View Post
    Colored smoke, "smoke bombs", are typically a fuel rich sugar chlorate mix with dyes added to give color. In operation the sugar chlorate vaporizes the dye and it cools and condenses into very small particles. Issues are if to hot the organic dye decomposes giving no color, and if it comes out of the container too hot it can ignite and burn in the air.
    If used in a rocket motor the burn rate under pressure of chlorate mixes is to high and grain is consumed before propellant grains.

    M
    I second that as I mixed some smoke pellets out of AP and burns white out in the open at atmospheric. I used the same standard aniline dyes used in the potassium chlorate powder mixes and they wash out. With the K chlorate,
    pretty red and purple colors seen.

    I've been told that potassium chlorates and ammonium perchlorate don't play well together and the K chlorate smoke mix could detonate under pressure. I was thinking that perhaps use a standard APCP smoke grain (your choice white or black smoke!)
    to continue to burn after motor burnout (case pressure is down) and then when that burns through to the end, it starts a colored potassium chlorate based smoke mix that burns with color at altitude. The key would be isolating the K chlorate smoke grain from igniting while under pressure of the motor burn and have it "catch" well after motor burnout at atmospheric pressure in the case. Of course would have to insulate the colored smoke grain from the case. The colored smoke I made in the past was mixing the dyes with the oxidizer and burning out in the open. I've wondered if a potassium chlorate composite color smoke pellet would burn with color at atmospheric or if the temperature of the composite would be too much for the color to be seen. If that were the case then trying to package a smoke mix in powder form inside a burning motor under pressure would be difficult.

    When it was pointed out to me that the colored stuff could detonate, I gave up as I wasn't interested in making things go boom. Plus, if it was easy to do, I thought the major motor makers would have come out with colored smoke grains for "at altitude" tracking. But then again, with motor ejection in the old days one wouldn't be able to get color to be seen during the motor burn as the smoke delay was timed so the ejection would occur "on schedule". Under pressure and temperature of the burn, any dye would be washed out anyways. With electronic deployment one really doesn't need to care how long the smoke burns as long as it doesn't damage the motor case or the closure. Once the case pressure is atmospheric I surmise a colored smoke mix should be able to give color at altitude out of a motor case.

    There are those who've used pull pin "cold" smoke bombs for activation after apogee deployment for effect. Tack the pin to the bulkhead with a kevlar string and secure the device to the harness. When the harness stretches out at
    apogee deployment, the pin gets pulled and the smoke is emanated. Some say if the smoke is still "coming" when the main deploys, it gets stained with the smoke dyes. Kurt


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