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  1. #31
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    11th May 2009
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    Scotch Weld DP 460 is another to consider. I don't have the numbers in front or me but I remember it being stronger than the Hysol and having decently high Tg.

    Last edited by watheyak; 16th December 2017 at 07:20 AM.
    Scott Wathey
    TRAPHX VP and Waiver Getter
    TRA 7726
    KF7EIV

  2. #32
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    Quote Originally Posted by Andrew_ASC View Post
    It makes me fuming mad, knowing a fin could literally rip off well above room temperature from friction with the air, yet some people don't understand. It's a number on a sheet with a random meaningless meaning to non engineer or non engineer student until a fin rips off in flight from a thermal load./RANT
    You don't need to be an engineer to understand this. However, I'm not so sure you understand what and where thermal load becomes an issue on these "hobby rockets".

    Aero heating at the fin root or fillets isn't the reason fins come off. Sudden, large increases in angle of attack and the associated load caused by other problems are what have removed the fins in just about every high mach failure. Loads of empirical evidence to back that up. (pun probably intended)

    Last edited by watheyak; 16th December 2017 at 07:26 AM.
    Scott Wathey
    TRAPHX VP and Waiver Getter
    TRA 7726
    KF7EIV

  3. #33
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    22nd January 2009
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    Hurdle Mills NC 27541
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    As a TAP, I think this is a very bad idea. Just the certification part. I'm all for stretching the envelope,AFTER you get your cert. Your choice. Good luck anyway.
    Jim Scarpine
    Underboss of The Carolina Rocket Mafia
    Tripoli NC
    TRA 1377 NAR 51510
    L3 TAP L3CC


    ICBM
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    Indiana Rocketry
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    Chicago Rocket Mafia


    www.starleopardrocketry.us

  4. #34
    Join Date
    19th January 2009
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    Portland, OR
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    As a TAP, I think this is a very bad idea. Just the certification part. I'm all for stretching the envelope, AFTER you get your cert.\

    WHY?
    I think it's a GREAT idea.
    Learn to push the envelope - especially if you plan on doing that more than once - while leveraging the tutelage of two TAPS that are critiquing your design & preparations.
    This is the PERFECT TIME - not later when you're fumbling on your own.

    We all view L3's totally wrong IMHO -- it is a teaching moment - the LAST teaching moment for many. Use it!
    Make SURE the candidate knows how to [safely] fly and recovery a high performance, mach-busting DD flight is my idea of a L3 flight.
    This is a great choice!
    Last edited by FredA; 16th December 2017 at 04:17 PM.
    Fred Azinger

  5. #35
    Join Date
    15th May 2016
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    2,349
    Quote Originally Posted by Andrew_ASC View Post
    Call Aeropoxy and ask for a TG just because it is unreported does not mean they do not have it. Tell em' you want it on a rocket at Mach 2+. The poor sales person will flip out and get an engineer. It isn't superior when you have zero data for that to compare with, bud. You may get a shocker when you hear how low TG some of their products are. They wouldn't sell me an epoxy for a M1.7 application. I told them on the phone lives were on the line. And I damn well meant it, because they were literally resting on a TG value keeping a fin on and a casing bonded in a 0.3s to Mach 1.5 application 200ft away from people. They gave a list of competitors. I might be an idiot for using Cotronics 4700 on an L-1 MD multistage, but it had TG value listed and exceeded these other guys specs. Heard the 4525IP is the room temp version non oven cure. Aeropoxy is good on paper at room temperature. With Aero heating.... You don't want it. Call Aeropoxy. They will get numbers you don't want to hear. Not trying piss on Aeropoxy products. Fine AIRCRAFT glue.
    First thing they want is how hot is your ROCKET going to get when its supersonic. When they don't sell you the epoxy... You realize something about how important a TG number is. Don't settle for unreported.
    I'm pretty sure I can guess why they sent you to their competitors, and it has nothing to do with TG

    Quote Originally Posted by Andrew_ASC View Post
    You wouldn't put a blowtorch (A thermal load) to a rocket motor casing with live fuel grains inserted. Why do people recommend epoxies without TG values listed that could fail if the application exceeds the value?????
    Where's my blow torch? I'd absolutely do this.
    David McCann
    Dave's Rockets | My Flights
    URRG |URRF 4| Level 2 | TRA# 14210

  6. #36
    Join Date
    9th December 2015
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    Fullerton, CA
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    Quote Originally Posted by FredA View Post
    As a TAP, I think this is a very bad idea. Just the certification part. I'm all for stretching the envelope, AFTER you get your cert.\

    WHY?
    I think it's a GREAT idea.
    Learn to push the envelope - especially if you plan on doing that more than once - while leveraging the tutelage of two TAPS that are critiquing your design & preparations.
    This is the PERFECT TIME - not later when you're fumbling on your own.

    We all view L3's totally wrong IMHO -- it is a teaching moment - the LAST teaching moment for many. Use it!
    Make SURE the candidate knows how to [safely] fly and recovery a high performance, mach-busting DD flight is my idea of a L3 flight.
    This is a great choice!
    This is my thinking as well. I'm an altitude and speed junkie. I love extreme rockets. I'd considered doing a low and slow L3 certification, but decided that I knew I'd probably never fly that rocket again if I went that route, it's just not where my heart is. I also know that it's a personal goal of mine to eventually hit 100k'. With that in mind, I decided to go the crazy route for my L3. I've also got full confidence on my TAPs who are advising me. One of the TAPs designed the Wildman kit that I'm basing my build off of, and we've been working with Tim at Wildman directly on the modifications that I'm wanting.

    Like I mentioned in the first post, if it's worth doing, it's worth doing in a ridiculous fashion.

    For now, I've got the air frame on order (Wildman Falcon, customized for single break dual deploy, custom carbon fiber fins), motor casing on order, a few new electronics specifically for this project on order, the CO2 ejection system for this on order, am working on software for the raspberry pi which will be on-board taking video, and will be ordering the recovery equipment somewhat soon. In the mean time, while I'm waiting for all of that to come in, I'm refining the OpenRocket sim file that I've created, beginning to flesh out my documentation on the project, and am continuing to read what others have learned about high altitude high speed flights, particularly on some of the things that Jim Jarvis has written.

    Once I begin building, I will certainly do a build thread for this beast.
    TRA 16109
    L1 - 07/09/2016 - Wildman Demon Sport on an Aerotech H195
    L2 - 07/08/2017 - Wildman 3" Punisher on an Aerotech J450DM

    Personal records
    Altitude - 15,556' AGL
    Speed - 1,272 MPH

  7. #37
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    15th May 2016
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    The only advice I have on it is to fly the new electronics on a more comfortable flight to get used to their operation. As for going too big, well isn't it better to do a flight like this under close supervision, rather than proving nothing flying a brick and then turning around and trying this alone? It's obviously not that black and white, but if you have a solid plan, and it's approved by the TAP, why does anyone else care what you fly? The L3 cert is just another step on a long journey no matter how you do it. I don't understand why people act like it's the last check and then you're just released free to do whatever you want.
    David McCann
    Dave's Rockets | My Flights
    URRG |URRF 4| Level 2 | TRA# 14210

  8. #38
    Join Date
    10th July 2007
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    Melbourne, Australia
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    Sounds like you have made valid choices for your L3 project based on the way you fly and future plans. One of the main goals is for you to be happy with your choices at the end of the effort, as well as learning along the way.

    Good luck with the project and flight.
    TRA 13430, Level 3

    "Everybody's simulation model is guilty until proven innocent" (Thomas H. Lawrence 1994)

  9. #39
    Join Date
    9th December 2015
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    Fullerton, CA
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    Quote Originally Posted by DavidMcCann View Post
    The only advice I have on it is to fly the new electronics on a more comfortable flight to get used to their operation.
    The plan is to fly this at ROC, and possibly LDRS on a K motor, which will keep it under both waivers. This will provide a sanity check that all electronics and recovery equipment are working and dialed in correctly before the L3 flight, which I'm hoping to make at XPRS.
    TRA 16109
    L1 - 07/09/2016 - Wildman Demon Sport on an Aerotech H195
    L2 - 07/08/2017 - Wildman 3" Punisher on an Aerotech J450DM

    Personal records
    Altitude - 15,556' AGL
    Speed - 1,272 MPH

  10. #40
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    26th November 2009
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    5,214
    Quote Originally Posted by FredA View Post
    As a TAP, I think this is a very bad idea. Just the certification part. I'm all for stretching the envelope, AFTER you get your cert.\

    WHY?
    I think it's a GREAT idea.
    Learn to push the envelope - especially if you plan on doing that more than once - while leveraging the tutelage of two TAPS that are critiquing your design & preparations.
    This is the PERFECT TIME - not later when you're fumbling on your own.

    We all view L3's totally wrong IMHO -- it is a teaching moment - the LAST teaching moment for many. Use it!
    Make SURE the candidate knows how to [safely] fly and recovery a high performance, mach-busting DD flight is my idea of a L3 flight.
    This is a great choice!
    Thing is Fred, not everyone wants nor can do a Mach busting, high altitude L3 flight due to a variety of reasons least of which is the appropriate venue and the experience of one's TAPs or L3CC people. Look where Mr. Scarpine is from and I can appreciate
    Jim's point of view. Also a person might just be wanting to pull off a run-of-the-mill L3 and fly conservatively there on out or take the approach of gradually walking up to higher performance.

    Chris? He's got the venue, he's got the TAPs who seem comfortable with advising for high performance so o.k. go for it. It's a better spot to be in with Tap/mentors who are comfortable with the intent as opposed to inexperienced Taps who can only look and nod their heads.

    I just hope Chris doesn't get a big head about it if he has success with it on the first attempt as the next project might not go so well no matter what it would be.

    The minute I get comfortable with something dealing with rockets, I can get bit. And...... It doesn't have to have anything to do high performance or Mach busting. Kurt

  11. #41
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    19th January 2009
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    Thing is Fred, not everyone wants nor can do a Mach busting, high altitude L3 flight due to a variety of reasons least....

    Thing is, clearly the OP has the space and desire. My point is why the heck would a TAP discourage this fine opportunity to teach???
    Fred Azinger

  12. #42
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    10th July 2007
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    Melbourne, Australia
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    One thing I would suggest if you are pushing the envelope a little, and that is to design your recovery system so in an off-nominal situation it keeps it all together and somewhat under control. Get the main out and keep it together under all circumstances if you can. A little extra height for the main might help with this also, especially if it doesn't come out cleanly and quickly.
    TRA 13430, Level 3

    "Everybody's simulation model is guilty until proven innocent" (Thomas H. Lawrence 1994)

  13. #43
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    23rd March 2011
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    Germantown, Ohio
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    Quote Originally Posted by FredA View Post
    Thing is Fred, not everyone wants nor can do a Mach busting, high altitude L3 flight due to a variety of reasons least....

    Thing is, clearly the OP has the space and desire. My point is why the heck would a TAP discourage this fine opportunity to teach???
    Fred, for the longest time I was one of the "low & slow for L3" crowd. However after seeing some of the projects and the amount of TAP talent out there, I must agree with you. Go for it and good luck!
    Gary Dickinson - Prefect
    Tripoli Mid Ohio #31
    TRA #5520 - L3 - TAP

  14. #44
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    26th November 2009
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    Quote Originally Posted by FredA View Post
    Thing is Fred, not everyone wants nor can do a Mach busting, high altitude L3 flight due to a variety of reasons least....

    Thing is, clearly the OP has the space and desire. My point is why the heck would a TAP discourage this fine opportunity to teach???
    I would venture to say that not all Taps /L3CC people are comfortable with that view and have their own ideas of what straightforward L3 attempt should be. Especially a flatlander without an appropriate venue to fly such a project. Also, who's doing the flying here the candidate or the mentor(s)?
    I have nothing against anyone who chooses that route but it wouldn't be the first one many would recommend to achieve a successful L-3. It's easier to pursue in some Geographical areas but not others. Kurt

  15. #45
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    19th January 2009
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    I would venture to say that not all Taps /L3CC people are comfortable with that view and have their own ideas of what straightforward L3 attempt should be.

    Not wanting to derail this thread, but ALL TAPS/L3CC's should be open to any rocket that can meet the safety code.
    If their PERSONAL experience and knowledge base is insufficient to handle an M-powered MD rocket then I suggest they are not qualified to be a TAP/L3CC, but at a minimum they should help the candidate find a TAP/L3CC who can handle their rocket.

    These people are not here to impose their personal flying "style" on candidates, but to validate the candidates rocket is built within the rules and will be flown in a safe manner....and to take the opportunity to educate along the way.
    Last edited by FredA; 18th December 2017 at 06:15 PM.
    Fred Azinger

  16. #46
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    23rd July 2011
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    Quote Originally Posted by FredA View Post
    These people are not here to impose their personal flying "style" on candidates, but to validate the candidates rocket is built within the rules and will be flown in a safe manner....and to take the opportunity to educate along the way.
    Exactly.
    Steve Shannon
    L3CC, TAP, Director, Tripoli Rocketry Association

  17. #47
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    Quote Originally Posted by Steve Shannon View Post
    Exactly.
    +1.....
    Gary Dickinson - Prefect
    Tripoli Mid Ohio #31
    TRA #5520 - L3 - TAP

  18. #48
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    Agreed but that doesn't mean it "has" to be a Mach screamer. Kurt
    Last edited by ksaves2; 18th December 2017 at 08:54 PM. Reason: is to it

  19. #49
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    7th July 2013
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    Toronto
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    For me the cert process is about the journey not the destination. However I know that, for the majority, the certification is strictly about the destination. While I agree that safety should always be the biggest concern, if that is addressed then let the flyer learn through their experience. Certainly if their is an obvious issue with the design, materials chosen, build technique, etc. then that is where the TAP's experience and input is critical.

    Not everyone is risk adverse. There are some risk takers in the crowd who feel that the best time to push the limit is when it counts and it is on the line. I say hats off to you SoCalChris and good luck with your attempt.
    Michael Pitfield
    TRA 14579 L2
    NAPAS BoD
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    CRC

  20. #50
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    Quote Originally Posted by ksaves2 View Post
    Agreed but that doesn't mean is "has" to be a Mach screamer. Kurt
    No, it doesnít. No flyer should ever fly something they feel uncomfortable with. Learning new limits is one thing, exceeding them is yet another. A flyer may wish to increase the probability of success by flying a more sedate flight. Thatís absolutely fine. Iím impressed by people who invest the time and effort to expand their knowledge and extend their limits. Iím definitely not impressed by people who fly beyond their limits while trying to impress others.
    Steve Shannon
    L3CC, TAP, Director, Tripoli Rocketry Association

  21. #51
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    15th May 2016
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    Quote Originally Posted by Steve Shannon View Post
    No, it doesn’t. No flyer should ever fly something they feel uncomfortable with. Learning new limits is one thing, exceeding them is yet another. A flyer may wish to increase the probability of success by flying a more sedate flight. That’s absolutely fine. I’m impressed by people who invest the time and effort to expand their knowledge and extend their limits. I’m definitely not impressed by people who fly beyond their limits while trying to impress others.
    Far too often I've seen a cavalier attitude on some shady flights, and a shrug when it popped/folded in half/etc.

    Myself, I do like being a little scared when they hit the button. But not reckless. I think finding the balance on that may be a razors edge sometimes.

    We all have different lines on acceptable risk, personally. But I do think as an organization we also have some good checks in place to reduce/minimize any recklessness.

    David McCann
    Dave's Rockets | My Flights
    URRG |URRF 4| Level 2 | TRA# 14210

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