Leo space Train - Simple Modification/Suggestion

Discussion in 'Low Power Rocketry (LPR)' started by BSNW, Mar 13, 2020.

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  1. Mar 13, 2020 #1

    BSNW

    BSNW

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    Like most Estes kits...I love them. The Leo Space Train is...in my book another hit from Estes. I love it!

    I do scratch my head at times as to why Estes still makes some larger kits to be so under powered. I have heard the guesses from other forum members as to why, but one can always adapt down. For example...the Goblin...small kit with a 24mm motor mount...YET the Mercury Red-Stone, ESAM, Interceptor and many others are 18mm.....Providing anemic power to beautiful kits. The Q-Jets are not even full D's and IMO, are a little underwhelming.

    I launched my regular Interceptor on a D12-3 and it was glorious...fast, straight and high...but not TOO high. A properly powered rocket. If I want to punt it in my back yard, I can put a C6-3 in it and hope for the best (I wont).

    I love this Leo Space Train, but saw straight away that it was yet another 18mm dog to be only launched on dead calm days with a 6 foot rod....yea okay. With all that wing surface area it needed, IMO, more power. The 18mm D10's are gone so out comes the trusty D12.

    The modification is simple to do and does not require much description. All the mod parts are from Estes. I did keep the 24mm motor tube to 6 inches like the original 18mm from the kit. My buddy Bruce who is a Roc-Sim guru is going to let me know how much clay to put in the nose. Thinking two pats of Estes clay should do it...like my Interceptor. I DID make room for the E12....yea baby.

    Anyway, I just wanted to say that this kit can be a bit more exciting, in my opinion, with this modification. I will post how much clay I added when I hear back from my personal Roc-Sim guru :) ENJOY!

    Photos below

    Andrew
     
  2. Mar 13, 2020 #2

    BSNW

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    Here it is...

    IMG_2810.JPG

    IMG_2812.JPG
     
  3. Mar 13, 2020 #3

    BSNW

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    Yes it does have an engine block...And I also chose to friction fit the motor as I dislike hooks. Never kicked a motor yet...it is also a cleaner look. The original motor mount set up is also pictured. I will use it in a small BT-60 scratch build for fun....nothing will go to waste :)

    IMG_2814.JPG

    IMG_2812.JPG
     
    Last edited: Mar 13, 2020
  4. Mar 13, 2020 #4

    BABAR

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    Estes website lists estimated weight

    96.4 g. (I am guessing this is without the motor)

    Source. https://estesrockets.com/product/007285-leo-space-train/

    Only recommended motor is C6-3

    Max lift off weight

    113 grams, mass of motor is 24.9 grams

    Source https://estesrockets.com/wp-content/uploads/Educator/Estes_Engine_Chart.pdf

    Quote from Estes Website from their own chart

    “Do not fly a rocket/engine combination whose lift-off weight exceeds the recommended maximum lift-off weight.”

    So I get 121.3 grams built stock with motor, assume wadding mass is negligible.

    It’s a gorgeous model, I am thinking to make it look optimal may need a bit more finishing weight than advertised.

    I am with you, recurrent theme is borderline underpowered designs. Previous examples are Venus Probe and ExoSkell.

    Hope you get good flights on your 24mm motors!
     
  5. Mar 13, 2020 #5

    BABAR

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    Last edited: Mar 13, 2020
  6. Mar 13, 2020 #6

    BSNW

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    Very good information! IMO, the 24mm mount and or D12 solves all these issues.
     
  7. Mar 13, 2020 #7

    BABAR

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  8. Mar 13, 2020 #8

    BSNW

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    Last edited: Mar 13, 2020
  9. Mar 13, 2020 #9

    BSNW

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    The D12 has more peak thrust and longer burn and is cheaper (at HL).....what's not to like?
     
  10. Mar 13, 2020 #10

    BABAR

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    Number one priority is getting it up to speed off the rail

    Thrustcurve.org using 42 mm diameter 96 gram dry weight , complex rocket, rough finish

    Quest D16 15 m/s off the rod, 109 meters altitude

    Estes D12 15 m/s off the rod, 143 meters altitude (really would be just a bit less since your modification would make the mass higher, but probably not a big difference)

    Estes C6 12 m/s off the rod, fails the test so no altitude given. Interestingly this IS the Estes recommended engine. So I think you are spot on, definitely if you fly this on a C6 do it on a windless day on a soft grassy field. Shame to have such a cool rocket go to pieces on first flight. Btw, I tried it with a perfect finish and it still failed at 12 m/s off the rod.

    Estes C5. 16 m/s off the rod, 91 meters altitude (but are C5s available now?!)

    Anyway, your decision to upgrade to 24 mm is certainly a good one, although going stock with a Quest D16 is reasonable.

    Agreed the D12s are cheaper. For a fantastic looking rocket that I definitely WANT BACK, I am okay going with the Quest D16, gets it safely off the rail as well as the D12, the lower altitude (109 meters vs 143) for me is a plus as it makes recovery easier.

    Interesting point here is the C6 fails according to thrustcurve.
     
    Last edited: Mar 13, 2020
  11. Mar 13, 2020 #11

    Scott_650

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    It is a bit puzzling why Estes doesn’t design their bigger/draggier rockets around 24mm motors and then just include the 18/24 adapters. That sounds like an excellent path to increasing the retail price a reasonable amount while giving the rocketeer a tangible and perceived added value plus ensuring solid performance of the rocket. The “kids and beginners should fly lower” perception is a questionable one - both categories tend to build heavy, leading to less than optimal performance of the rocket on 18mm BP motors. I can’t think of anything more discouraging to any beginner than building a nice, shiny new rocket and then watching it crash due to lack of power. Or having an informed beginner build an Estes kit only to have it flown on a competitor’s motor!
     
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  12. Mar 13, 2020 #12

    BABAR

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    https://estesrockets.com/product/007285-leo-space-train/
    Is my source for rocket estimated weight.

    Correction (or at least clarification)

    Using thrustcurve.org, the Quest D16 does get it off the rail safely if I use the Estes build weight from the web site of 96.4 grams, I am assuming that is without motor. BUT it doesn’t make it if I bump it up to 100 grams. And I don’t know if swapping out the C6 for the D16 will require any additional nose weight, in any case, there is not any leeway for adding any extra weight. The D16 certainly doesn’t give any leeway for “overbuilding.”

    Using the Estes D12 thrustcurve will let me bump the dry weight up to 130 grams and still get off the rod at 15 m/s. So while I suspect the 24 mm modification will need some additional nose weight, there IS leeway to add some with the D12 but not with the D16

    So FWIW I think your decision to go for the 24 mm mod was a very good one.
     
  13. Mar 13, 2020 #13

    John Taylor

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    I would guess add nose weight at the difference between the D12 and the C6. The D12 is about 42g.
    And the C6 is about 27g.
    Si that's 17g. added weight. Unless the motor mount is more.
     
  14. Mar 13, 2020 #14

    John Taylor

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    Correction the C6 is about 25g.
     
  15. Mar 13, 2020 #15

    BSNW

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    Wow..this is turning into a very good and informative discussion. Lots of good information.

    I know what people may say....but if Estes can make their OWN (not Aerotech) 18mm and or 24mm basic composite motor (or two) to cover some larger kits...it would be a good thing IMO. I am not talking about a full line, just a good FULL D composite in 18mm or 24mm and or a mid range or full E in 24mm. This would do wonders in some of their larger kits. I fly mostly EX high power....and I know there are some real simple formulations for a basic propellant out there. Anyway......for now I am a big fan of the D12 and E12.....cheap...reliable and fun.
     
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  16. Mar 14, 2020 #16

    BMcD

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    I have this kit, and as I look at the face card I feel like its design lends itself to being stretched. It is supposed to be a space train, right? Carrying lots of passengers and cargo. So do any of you OR or RS gurus know how long I’d need to extend the main BT in order to have 2 cal stability with a 24mm MMT and no nose weight?
     
  17. Mar 14, 2020 #17

    BSNW

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    Come to think of it......an RMS F12 would be a fun motor fot this too. I am surprised I dont see more F12's at launches. It is a GREAT model rocket motor! Nice longer burn too! Try one in a light model with a 24mm mount. My Interceptor will get to ride on one soon! Should be fun!........on a calm day of course

    Andrew
     
    Last edited: Mar 14, 2020
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  18. Mar 14, 2020 #18

    BSNW

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    I dont know but it may not be much. If you like the look of it longer...go for it! Sounds like fun! This model is a 99% copy of a real life rocket that was canceled before they built it. I think Northrup was the contractor. Either way have fun!
     
  19. Mar 14, 2020 #19

    BSNW

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    IMPORTANT FYI !!!!

    So if anyone goes with the modification listed above....I found out the hard way that you have to remove 1.6 to 2.0 cm from the aft "square thing" for the other tailcone to fit! Sorry about this. I will post photos to tonight... It still looks great and is a small detail. Fun times.
    Andrew
     
  20. Mar 14, 2020 #20

    hcmbanjo

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    A C5-3 motor is recommended in the new Estes 202 catalog, but not yet on the website pages.
    Sorry, I didn't weigh my finished builds.
     
  21. Mar 14, 2020 #21

    Scott_650

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    Not to be flip or cynical but I’m willing to surmise the length of more than one Estes kit is at least partly determined by the packaging requirements - hang bags can only be so long to fit in over packs or on retailers shelves. A bit more length on the carrier rocket probably would have no impact on stability. Moving the parasite rocket forward or aft could be a problem but moving the nose cone further forward, not - look at other similar designs with longer carriers, like the Estes Orbital Transporter, the Centuri SST Shuttle, or the Squirrel Works Dogfight - all stable flyers. The Space Train would look pretty nifty with some more length.
     
  22. Mar 14, 2020 #22

    BABAR

    BABAR

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    Where can you currently get a C5-3? Is this going to be released soon? I found a set of three on EBay for $38

    https://www.google.com/shopping/pro..._Qh_vGtA,prmr:1,pid:12216745359712319887,cs:1

    Seems like if this is the optimal Estes motor for the stock Space Train, miiiiight have been a good idea to release the motor at or before they released to the rocket.
     
  23. Mar 14, 2020 #23

    dpower

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  24. Mar 14, 2020 #24

    Arsenal78

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    Speaking of QJets being underwhelming, I attempted to fly an Estes Corkscrew on a B4 QJet. Note that this rocket can fly down to an 18mm Estes A motor. The B4 QJet is a pathetic excuse of a motor. It didn't even have enough power to lift that rocket, it just flopped on the ground after getting like 20ft in the air. Haven't tried a C12 in it but I'm just going to fly standard Estes motors in my stuff and stay away from QJets.
     
  25. Mar 15, 2020 #25

    BSNW

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    Okay-

    I hope you are all doing well. Here are the photos I was talking about concerning this modification. I should have thought this through more and I would have seen this ahead of time. It all worked out and the fix is, IMO not a huge deal and is simple. Below shows the section that has to be removed from the aft end. After I cut the section off I then rounded the back end with 220 sand paper.

    IMG_2816.JPG
     
  26. Mar 15, 2020 #26

    BSNW

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    Here are some photos of how things will look. This is a kit where I will actually keep these sections separate for painting and join them when done. I did test if I can get the tail cone on AFTER the wing is glued on. I will glue 3/4 of the way down the center towards the aft end and join. After putting the tail cone on I will then GENTLY bend out the aft end and drop in CA with me needle applicator. Should work out just fine.

    This is a cool kit. Photos below. Have a good day everyone.
    Andrew

    IMG_2822.JPG

    IMG_2824.JPG

    IMG_2827.JPG
     
  27. Mar 15, 2020 #27

    burkefj

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    If you're already marginal on a c motor then putting a 24 mm mount in and the required extra nose weight is only going to make it worse once you stick an adapter and a c motor back in it, you can ask why they don't just design it for 24 millimeter and be done but adding an adapter doesn't do you any good in many of these cases.

     
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