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  1. #1
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    Why does the AT 24/60 case exist?

    I'm trying to find a compelling reason for that case to exist. First, the case only has 3 reloads available, all of them being F-35W which come in a 2 pack. The only difference in all three is the delay time. Second, the 24/40 case has 2 slightly more powerful motors available which come in a 3 pack for only a few dollars more. Its like getting a full reload for around $3 if you go the 24/40 F39 route. I've compared the thrust characteristics of both options and they are similar. The main appreciable difference is that the 24/60 uses the White Lightning and the F39s in the 24/40 are Blue Thunder. What else am I missing? I'm new at all of this so there has got to be a reason for its existence that I'm not seeing.

    Thanks.


  2. #2
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    AT has had NBT, FJ, and R loads stuck in the cert process for nearly a year at this point.


  3. #3
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    Quote Originally Posted by dhbarr View Post
    AT has had NBT, FJ, and R loads stuck in the cert process for nearly a year at this point.

    That is correct, don't know what is going on. I will buy a case or two when and if the reloads ever come out.
    _______________________
    Jeff - NAR #76531 -L2

  4. #4
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    The 24/60 case is much nicer than the 24/40. I like the F35, but it would be nice to have more choices if the other loads ever get certified.

  5. #5
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    Quote Originally Posted by DGBrown View Post
    The 24/60 case is much nicer than the 24/40. I like the F35, but it would be nice to have more choices if the other loads ever get certified.
    Can you elaborate? It looks like its just 20mm longer to me.

  6. #6
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    The 24/60 provides an option for a reloadable that is generally the same size as Estes E9/12 and can provide some extra thrust. You realize that extra length means extra propellant and thus more total impulse. Plus, most everyone likes propellant options and the longer case appears to support some them.

    That being said, since there has only been one load out there, I would have preferred to have bought another 24/40 as I lost my last one shortly after I got the 24/60.
    Dick Stafford
    The member formerly known as the Pointy-Haired Moderator.
    The Original Rocket Dungeon
    Volunteer compiler of product news for ROCKETS Magazine

  7. #7
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    Yes, I did realize the logistics of the extra 20mm. My point was that even though they had an extra 20mm, the one current load didn't really utilize it. If you look at the total impulse of the two loads I was comparing you'll see what I mean. The 24/60 case is 33% longer yet the load thats available is only 15% higher in total impulse.

    I just hope they do get the afore mentioned reloads certified because I'd definitely dig the extra options.

  8. #8
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    Someone from Aerotech can correct me if I an wrong.

    24/60 was created to fit the new Estes E9 sized models but provide 2.5 times the total impulse.

    The F35 has more total impulse than the F39. Look at the actual test data.

    The 24/60 has thicker walls and stronger threads so that it can withstand greater pressure for different reloads and higher efficiency.

    Additional reloads were stalled by a number of factors, including the California State Fire Marshal having to enforce an old law that prohibited metal casings and handling of ingredients for "Model Rocket Motors". This was the result of an enforcement action against someone who then said something to the effect of: if you are going to enforce law X on me, then you need to enforce law Y on everyone else. This was in approx. Oct 2010.

    As a result any new reload was Classified as a High Power Rocket Motor and couold only be launched at high Power Rocket launches with the appropriate permits and licensed Pyrotechnicians present. Insurance would be VOID if launched at a Model Rocket launch since the permit would not cover HPR.

    With the help of many, I was able to get that law changed. That took effect Jan 1, 2016.

    With the law changed, Aerotech was able to resume development of additional RMS reloads for this and other casings. They were going to have additional 24/60 reloads years ago, but that got derailed by the law situation in the large CA market.

    (Cesaroni was also affected and all their motors are Classified as HPR in California. They were going to work on new Classifications in 2016 but the accident derailed that. They will likely resume pursuing Reclassification soon).

    The big delay is NAR S&T. There is no official word from the NAR as to WHY there is a delay. If it is NAR testing facilities, it would be nice to let everyone know. If it is a paperwork submittal situation from the manufacturer, then they shold know and tell us (and not blame NAR). I have no firm idea what is the root cause of the delay, but it is annoying for TARC. The 24/60 is a great TARC motor casing - especially with more motor options (someday).

    Quote Originally Posted by DeepOvertone View Post
    I'm trying to find a compelling reason for that case to exist. First, the case only has 3 reloads available, all of them being F-35W which come in a 2 pack. The only difference in all three is the delay time. Second, the 24/40 case has 2 slightly more powerful motors available which come in a 3 pack for only a few dollars more. Its like getting a full reload for around $3 if you go the 24/40 F39 route. I've compared the thrust characteristics of both options and they are similar. The main appreciable difference is that the 24/60 uses the White Lightning and the F39s in the 24/40 are Blue Thunder. What else am I missing? I'm new at all of this so there has got to be a reason for its existence that I'm not seeing.

    Thanks.

  9. #9
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    Quote Originally Posted by DeepOvertone View Post
    Can you elaborate? It looks like its just 20mm longer to me.
    The casing is thicker, mine measures .064" before the step, and about .070" in the middle of the case, versus .035" for the 24/40. The closures are also more substantial, with better threads. They also use the same thickness for the forward and aft o rings, which I like better so I don't have to read through the parts list to remember where the skinny one goes.
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  10. #10
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    Simple answer:

    30 grams of propellant.

    They can and will fit more total impulse in the 24/60 with bifurcated grains.

    http://www.nar.org/pdf/shipping_rocket_motors.pdf


    Quote Originally Posted by DeepOvertone View Post
    Yes, I did realize the logistics of the extra 20mm. My point was that even though they had an extra 20mm, the one current load didn't really utilize it. If you look at the total impulse of the two loads I was comparing you'll see what I mean. The 24/60 case is 33% longer yet the load thats available is only 15% higher in total impulse.

    I just hope they do get the afore mentioned reloads certified because I'd definitely dig the extra options.

  11. #11
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    Quote Originally Posted by shreadvector View Post
    Simple answer:

    30 grams of propellant.

    They can and will fit more total impulse in the 24/60 with bifurcated grains.

    http://www.nar.org/pdf/shipping_rocket_motors.pdf

    AH-HA! So they ran in to the 30 gram shipping limit and thats where the total impulse comes from. Bummer. I hope they do get split grains certified! I can see it being a versatile case. I'm guessing the ID is a little smaller than the 24/40 to allow for more wall thickness. Its too bad they couldn't have the same ID and figure out a way to use the 24/40 loads with a spacer like on the 38mm. Although I dont know how that could have worked since the forward closure is completely different.

  12. #12
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    26th February 2017
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    Also keep in mind all the 29mm hobby reloads are hazmats. I hope when the new launch loads get certified this will be my go to for F motors.

    Now why are the 29mm hazmats? Could the grains be cut and they be recertifed?
    NAR #102778
    L1 - 4/7/17 - Loc IV H123W, LDRS36

  13. #13
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    Quote Originally Posted by BradMilkomeda View Post
    Also keep in mind all the 29mm hobby reloads are hazmats. I hope when the new launch loads get certified this will be my go to for F motors.

    Now why are the 29mm hazmats? Could the grains be cut and they be recertifed?
    If you're talking about the 29/40-120 case only the F reloads and the G138 are hazmat.

  14. #14
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    Shreadvector brings up a good point! Who does NAR S & T answer too? Everybody answers to someone, and if their performance is sub-standard for whatever reason - they get replaced. Its been a long time and no one really knows what the problems is? (maybe we need Mr. Trump to start tweating at them)

  15. #15
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    Quote Originally Posted by mhanna View Post
    Shreadvector brings up a good point! Who does NAR S & T answer too? Everybody answers to someone, and if their performance is sub-standard for whatever reason - they get replaced. Its been a long time and no one really knows what the problems is? (maybe we need Mr. Trump to start tweating at them)
    drain the swamp!
    Handeman

    TRA #09903 L3 3/29/2015

    "If you don't use your head, you have to use your feet!" my Dad

    Tripoli Central Virginia #25 - BattlePark.org

  16. #16
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    Quote Originally Posted by DGBrown View Post
    If you're talking about the 29/40-120 case only the F reloads and the G138 are hazmat.
    I noticed that and I’m curious why that is. I understand the g138 of course but why are the F’s?

  17. #17
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    Sometime the swamp needs to be drained to fix the problem, The NAR web site says "a motor will be tested within 60 day of reception, results published within the next 30 days." Its either the manufacturers or the testers fault - this isn't brain surgery, someone knows whats going on. Seems like the rock community has a right to know. I don't even fly those cases but wrong is wrong.

  18. #18
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    They already drained the swamp.

    http://web.mit.edu/fnl/volume/242/construction_POP.html


    Quote Originally Posted by Handeman View Post
    drain the swamp!

  19. #19
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    Quote Originally Posted by DeepOvertone View Post
    AH-HA! So they ran in to the 30 gram shipping limit and thats where the total impulse comes from. Bummer. I hope they do get split grains certified! I can see it being a versatile case. I'm guessing the ID is a little smaller than the 24/40 to allow for more wall thickness. Its too bad they couldn't have the same ID and figure out a way to use the 24/40 loads with a spacer like on the 38mm. Although I dont know how that could have worked since the forward closure is completely different.

    The shipping regulations suck, and really make no sense. 25 lbs of 30 gram grains in a box = 25 lbs of 100 gram grains in a box.
    _______________________
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  20. #20
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    Quote Originally Posted by mhanna View Post
    Sometime the swamp needs to be drained to fix the problem, The NAR web site says "a motor will be tested within 60 day of reception, results published within the next 30 days." Its either the manufacturers or the testers fault - this isn't brain surgery, someone knows whats going on. Seems like the rock community has a right to know. I don't even fly those cases but wrong is wrong.
    Very clever not saying "this isn't rocket science"...

    Seriously, though, I can't wait for these to finally get certified- the current one motor lineup seems kinda pointless, especially when you can get no less than 8 motors in 3 propellant types in the 24/40...
    NAR #104043

    crmrc.org

  21. #21
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    Back to the 24/60, the F35 is a great motor.
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  22. #22
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    Quote Originally Posted by shreadvector View Post
    And a railroad built right to the front door!!!!
    Handeman

    TRA #09903 L3 3/29/2015

    "If you don't use your head, you have to use your feet!" my Dad

    Tripoli Central Virginia #25 - BattlePark.org

  23. #23
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    While the 24/60 only has one load currently the F35W is an absolute kick to fly, my 24mm modded Estes Nike Smoke goes to 2400'. The TARC teams evidently like it as well. I am looking forward to getting more loads as well.
    Rich

    NAR# 99154

    L3-4x upscale Estes Cherokee-D- AT M1297W 5/28/2016 http://www.rocketryforum.com/showthr...r-rharshberger

    TriCities Rocketeers NAR section# 736 http://www.tricitiesrocketeers.org/

  24. #24
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    Don't know why 24/60 exists. I just trolled AeroTech Open Thread for 24/80. 24/120. 24/160. 24/200. 24/240 options.

    I'd totally buy an HPR version and maybe a 24/120 MPR...

  25. #25
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    So they had new loads a year ago... Okay. Why no cert?

  26. #26
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    Quote Originally Posted by Andrew_ASC View Post


    So they had new loads a year ago... Okay. Why no cert?
    Really?
    Steve Shannon
    L3CC, TAP, Director, Tripoli Rocketry Association

  27. #27
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    Everyone is likely just rolling eyes at me... The other was redline. I guess the loads are stuck in Cert process.


    New blue thunder. Aug. 19,2016.

    Fast Black Jack. Aug. 19,2016.

  28. #28
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    Not sure I get the picture of the early MIT building and its connection to this topic? But its a lovely picture, thanks.

  29. #29
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    Quote Originally Posted by Andrew_ASC View Post
    Everyone is likely just rolling eyes at me... The other was redline. I guess the loads are stuck in Cert process.


    New blue thunder. Aug. 19,2016.

    Fast Black Jack. Aug. 19,2016.
    Yes, those are the three loads I mentioned in post 2 of this very thread. There's also a pair of 29/40-120 loads stuck waiting on cert, Redline and Dark Matter I believe.

  30. #30
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    Quote Originally Posted by Andrew_ASC View Post
    Everyone is likely just rolling eyes at me... The other was redline. I guess the loads are stuck in Cert process.


    New blue thunder. Aug. 19,2016.

    Fast Black Jack. Aug. 19,2016.
    I apologize for the tone of my word, Andrew.

    Steve Shannon
    L3CC, TAP, Director, Tripoli Rocketry Association

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