New Build. Have Questions.

Discussion in 'High Power Rocketry (HPR)' started by Valkyrie, Jul 9, 2017.

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  1. Jul 10, 2017 #31

    MikeyDSlagle

    MikeyDSlagle

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    Awesome fights.
    Nice work on the slideshow too.
     
  2. Jul 10, 2017 #32

    o1d_dude

    o1d_dude

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    'I battle gravity'

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    Thanks for posting the video. Top marks for the Filter soundtrack. Nice Shot.

    Unbelievably straight flights with virtually no roll at all.

    Now I'm anxious to start working on my Screech 2.6.
     
  3. Jul 10, 2017 #33

    DavidMcCann

    DavidMcCann

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    Thanks guys. I can't believe it's been two years since I popped those four flights off. I need to get to work on something cool again.
     
  4. Jul 11, 2017 #34

    Valkyrie

    Valkyrie

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    More progress. I made a jig from cardboard and installed the fins. I filleted the fin roots to the motor tube as well as to the inside of the BT. Overkill? I figured why not, its certainly not gonna hurt and is a very small amount of weight. It was tedious and I was able to get them done with a minimal amount of mess. I did the external fillets on one fin. using the tape method, I dyed the epoxy with graphite to help see what I was doing and to show any spots where there was an imperfection. I used a piece of PVC tubing to mark and then pull the epoxy smooth. It worked very well. I have two more fins to do. The aft CR is installed also. I'm gonna skim coat it with JB weld and instead of a pair if circumferencing fillets there just mix enough to do everything and be done with it and install the motor retainer.
     
  5. Jul 12, 2017 #35

    Valkyrie

    Valkyrie

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    Out of curiosity, How fast and how high can this rocket fly successfully? Generally?
     
  6. Jul 12, 2017 #36

    djs

    djs

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    If you put a Loki K motor in there- very high and very fast :). Depends on how you built it.
     
  7. Jul 12, 2017 #37

    Valkyrie

    Valkyrie

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    I out another fillet on the fins this evening. Its tedious and I do one at a time. Three more to go!

    Starting to think that it will be done by the end of the week, minus paint? Much faster to build than I anticipated. I am looking through the recovery gear that I got with it a small drogue and a 30" main. I am thinking of using a 4' main? With a chute release I can set my altitude pretty easily for main deploy and I see that many rockets that get beat up under the stock chutes on landing? Why not slow it down a little more if I have a good handle on the deployment altitude? I'm way ahead of myself but I'm just thinking.

    I have a lot to work on. Paint is gonna be tough. I don't want to use rattle can paint on it, I'm thinking of a simple spray gun and automotive paint. I want to go with heavy flake candy apple red. The entire rocket one color and maybe an accent on the switch band of the AV bay.

    Also, I'm going with SS machine screws to hold the NC and forward bay together in case I ever make it a true DD. What size and type screws would you recommend? Should I use anchors on the back side? This thing is pretty cool looking. Tall and looks fast too but my experience with anything bigger than 29mm E and F motors is about it.

    Does anyone have a .ORK file for this I can tinker with? I don't know much about using this program and starting from scratch seems impossible.
     
  8. Jul 12, 2017 #38

    Nytrunner

    Nytrunner

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    I don't have an ork for that rocket, but I can give a couple pointers :D

    The cool thing is, you Don't have to get every single component in place. Just make the externals the correct size (Nose, tube, fins), then put an internal tube in, set it as motor mount, and you're done with construction.

    Place (n) parachutes in there set to open according to your flight plan. You're done with components! (Although it's hard to model a chute release flight)

    Then in the parts list click Sustainer, and go to Override CG. You'll weigh and balance your model and just make your simulation match.

    Last thing is the surface finish which will be unique to your rocket anyway. Then it's off to the simulations! (Make sure your ground level altitude is set for where you launch. I forgot to change mine for awhile when I moved from a river Delta (~97') to Hill/plain country (~900')
     
  9. Jul 12, 2017 #39

    OverTheTop

    OverTheTop

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    If it were my bird I would use M3 countersunk screws, with some sort of insert inside, rather than just tapped into the f/g tube. An alternative might be to add some more f/g to thicken up the airframe where the threaded holes need to go and tap them out. I assume you are in the USA so there might be some imperial screws that are more available for you, and a slightly coarser thread than the M3 has would possibly be an improvement.

    I have used pan head screws in the past but the CSK ones look better.

    If you are countersinking the f/g tube it can come out a bit out of round (typically triangular if you are using a drill for countersinking) if you don't have a tool that has a slightly negative rake on the cutting edge. An alternative to finding such a tool is to put a few layers of cloth (old t-shirt or similar) between the workpiece and bit. It has the effect of making the hole nice and round. Drill slowly so it doesn't bite in and ruin the tubing, especially if you are using a standard drill.
    Countersinkingresize.JPG
     
  10. Jul 12, 2017 #40

    Valkyrie

    Valkyrie

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    And the fins are done and the fillets are nice! I also put the aft CR in and used JB weld as the aft epoxy since I figure this is a high heat area.

    The fins are filleted to the motor tube as well as interior of the BT and the exterior.

    Not sure whats next.
     
  11. Jul 13, 2017 #41

    DavidMcCann

    DavidMcCann

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    K1127, J510, K1127, j1026

    all around 9,000 feet and Mach 1.2ish
     
  12. Jul 13, 2017 #42

    Valkyrie

    Valkyrie

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    Well the hard stuff is done. I feel pretty confident that the motor mount and fins are as well constructed as they can be. I'm gonna mount the motor retainer later this afternoon. It's an Aerotech screw on style.

    Any recommendations on son a decent altimeter to record flight data? I was thinking the Altimeter Three from Jolly Logic? I'm going to makr and drill the rail button mounting holes also this weekend.
     
  13. Jul 14, 2017 #43

    CzTeacherMan

    CzTeacherMan

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    That's "Aeropack"...
    The JL A3 is pretty sweet. Very versatile, and I love the Bluetooth connectivity.
    Let's see some pictures!!
     
  14. Jul 14, 2017 #44

    Steve Shannon

    Steve Shannon

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  15. Jul 14, 2017 #45

    DavidMcCann

    DavidMcCann

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    the Jl3 is nice for recording and ease of use. However, you could get an altimeter capable of doing deployments as well, and what I feel are better graphs of flight data for less money with an RRC3 or SLCF
     
  16. Jul 14, 2017 #46

    Valkyrie

    Valkyrie

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    Yep it's Aeropack, lol. Anyway. I have some pictures but they will not upload. Any ideas?
     
  17. Jul 14, 2017 #47

    Valkyrie

    Valkyrie

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    Here's the fins and everything but the retainer[​IMG][/IMG]
     
  18. Jul 14, 2017 #48

    Valkyrie

    Valkyrie

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    Here she the motor tube with the Kevlar recovery harness in place with JB weld.

    [​IMG][/IMG]
     
  19. Jul 14, 2017 #49

    DavidMcCann

    DavidMcCann

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    Looking good
     
  20. Jul 14, 2017 #50

    Valkyrie

    Valkyrie

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    Thanks. Not sure what is next. I need to get the launch button holes located and drilled but I am thinking that the tube is pretty thin and that building up the area and tapping the holes out is the way to go. I was thinking a piece of radiused glass epoxied to the outside of the tube at the button locations and then and tapped for the button screws? And where would I get a small piece of glass that would match the outside radius?
     
  21. Jul 15, 2017 #51

    DavidMcCann

    DavidMcCann

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    You could get an av bay band and cut it up. It's not a terrible idea

    i just drilled holes slightly smaller than my screws, filled it with epoxy, and then screwed the buttons in. No additional reinforcement I've done almost everything else I build that way, and it seems to work. Haven't ripped one off yet. There's typically not a lot of force on the buttons.
     
  22. Jul 15, 2017 #52

    CzTeacherMan

    CzTeacherMan

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  23. Jul 15, 2017 #53

    CzTeacherMan

    CzTeacherMan

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    Ditto David's plan. I even leave out the epoxy and have never had a button failure.
     
  24. Jul 15, 2017 #54

    Valkyrie

    Valkyrie

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    What would be a good sized motor case for this rocket?
     
  25. Jul 15, 2017 #55

    CzTeacherMan

    CzTeacherMan

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    I'd use a CTI 38/3-grain all day long, or an AT 38/360.
    Those are all L1 motors though. But with this build, it'll be easy to get your L1.
    Also, if you get the spacers (CTI) or the RAS (AT, spacers), you'll be able to fly it on smaller motors in that case.
     
  26. Jul 15, 2017 #56

    Valkyrie

    Valkyrie

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    I'm trying to think of every possible way to make this a solid model that will function. I don't want to leave anything to chance.
     
  27. Jul 15, 2017 #57

    CzTeacherMan

    CzTeacherMan

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    Yeah. 360 or 3-grain gives you a great range of motors to fly at a great price. You can really punch it with some of the high thrust motors or go easy with some softer motors. After you've been flying it for awhile, you can get a larger case too really kick it, but the 3-grain size is a great value every way around. Definitely check what your local dealer carries to decide between AT or CTI.
     
  28. Jul 15, 2017 #58

    noffie79

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  29. Jul 16, 2017 #59

    Valkyrie

    Valkyrie

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    I'm getting to the finish line on air frame construction. I used three #8 1/2" sheet metal screws to secure the forward tube to the AV bay and I'm gonna do the same to attach the nose cone to that should I ever want to try DD. Turns out that the fin slots aren't exactly 120 degrees apart, I used the slots to mark where I would drill holes in the rest of the body by transferring them to the AV bay and then to the body tubes. Its only slight and not able to be seen, just that the holes only line up one way. Not a big deal. Once I'm finished with this part, I have to decide on shear pins or friction fit and rig the recovery harness assembly.

    Otherwise, its done! I feathered out the fin fillets with some 400 sand paper. I also put together a model in OR though, I don't know if its accurate or not.
     
  30. Jul 16, 2017 #60

    Valkyrie

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    While I am thinking about the recovery set up I ordered a 48" main chute. I plan on using the 12" drogue chute that was included also. I am not sure how to actually rig everything though? The kit came with two lengths of 1/2" tubular nylon. I epoxied a Kevlar harness loop to the motor tube that terminates about an inch or so from the end of the BT.

    Any thoughts?
     

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