Help identify CTI 29mm 3G reload, offset core

Discussion in 'Propulsion' started by 75Grandville, Sep 10, 2019.

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  1. Sep 10, 2019 #1

    75Grandville

    75Grandville

    75Grandville

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    Title pretty much sums it up. I've got a 3 grain 29mm CTI motor with an offset core. No idea what the propellant is. I can post a picture after I get home from work.

    Would like to fly it, but also would like some idea what it is so I can set the delay accordingly, ensure the rocket will be stable, etc.
     
  2. Sep 10, 2019 #2

    mikec

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    H54 or maybe G54.
     
  3. Sep 10, 2019 #3

    boatgeek

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    Definitely either an H54 white longburn or G54 red longburn. They're pretty comparable, though the H has a hair more impulse and a hair lower peak thrust. The big deal is that the H is a 10-second nominal (undrilled) delay and the G is 12 seconds.
     
  4. Sep 10, 2019 #4

    75Grandville

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    Thank you both! I checked back through my orders at various vendors. Other than being appalled at how much I spend, I got no further info about this. Which means I bought it onsite somewhere.

    With the information above, I plugged in some simulations. Looks like both motors would like a 9.25 second delay. So, if I shave 2 seconds off the delay, I'll either be 1 second early or one second late. I think I can live with that.

    My guess is that it's a G54. I remember being fascinated by the fact that CTI had a 100% G, and thinking it would be fun to go for the G altitude record.

    Was hoping it was a G33 (Mellow) - that would have been fun in my Turbo Vortico, and would also explain why the ejection charge is missing.
     
  5. Sep 10, 2019 #5

    Nytrunner

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    G33 has an ejection charge and I don't recall it being a moonburner (offset)
     
  6. Sep 10, 2019 #6

    Rocketjunkie

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    The Mellow motors are all Bates grains, just a very slow propellant. If the propellant is reddish, its a red. CTI adds color to the propellant to match the flame color.
     
  7. Sep 11, 2019 #7

    75Grandville

    75Grandville

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    @Nytrunner, there was an ejection charge - I removed it for reasons that I can't recall. The only reason I can think of for removing the ejection charge was to fly it in a Turbo Vortico.

    @Rocketjunkie, of course now I can't seem to find the motor. Hopefully it's in with the big box of CTI casings and reloads. I just lack the energy to dig it out at the moment.
     
  8. Sep 11, 2019 #8

    tbonerocketeer

    tbonerocketeer

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    use a knife and cut a tiny sliver of propellant off a grain along the core edge. Burn that sliver and see if it is red flame or white smoke....
     
  9. Sep 12, 2019 #9

    Maxwelljets

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    It would be cool if there were a thread where people posted pics of grains of known propellant types to help people identify mystery motors.
     
  10. Sep 12, 2019 #10

    tbonerocketeer

    tbonerocketeer

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    Problem is that some propellant is the same look and color but different flame effect
     
  11. Sep 12, 2019 #11

    Maxwelljets

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    That's definitely true, but it'd still help narrow it down quite a bit. Combine the reference photos with the fact that most cases don't include all types of propellant and you could probably solve a decent fraction of these questions.
     

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