Hi, New to the forum

Discussion in 'Low Power Rocketry (LPR)' started by Off Grid Gecko, Mar 24, 2020 at 3:27 AM.

Help Support The Rocketry Forum by donating:

  1. Mar 24, 2020 at 3:27 AM #1

    Off Grid Gecko

    Off Grid Gecko

    Off Grid Gecko

    Active Member

    Joined:
    Tuesday
    Messages:
    28
    Likes Received:
    2
    Gender:
    Male
    Location:
    Southern Missouri
    Been a long time lurker and promised myself that I would set up an account tonight. My hopes are to get an NAR membership sometime this year and go for my L1, but I've been fiddling with smaller rockets that I can simply go outside and launch. Don't worry, my "back yard" is a quarter section of property, so there's plenty of space, though many trees as well.

    Anyway, there's a lot about me, but I want to focus on my current thing, LPR.

    I've made several rockets over the years out of paper and small engines. I even built an L1-capable rocket a couple years ago from nothing but kraft paper, plywood, and lots of "special" glue to strengthen everything, but it eventually got destroyed before so much as a test launch.

    Most recently, I made a little rocket, the Angry Pickle, out of a paper bag and some manilla paper. Flew great, but let's just say I would have been better off to roll a few more layers on the tube. It crinkled, so it sits on my shelf after its maiden flight the other day. At least I used up that last 1/2A motor that was laying around.

    Now I'm looking at getting a kit, but none of the LPR kits excite me too much except for a little egg launcher from Apogee. It's called the Courier, I think. Adorable little rocket. But after pricing out some components, I'm leaning toward another scratch build. My cart is around $40 and includes a couple pre-slotted 33mm tubes, four nose cones, an engine mount for same, a parachute, some B motors (I think B6-4), 1/8" balsa sheet, and 1/4" launch lugs (for my home-made launch-pad). So that'll be a 40 dollar rocket including motors, and enough gear to make another BT-55 rocket on the cheap, just add another parachute and motor mount when I'm ready, essentially.

    As much as I want my L1 cert (actually I want the L2), money is tight these days and I need to budget things out. I figure I can build another L1 piece by piece as money and time permit rather than rushing it, and in the meantime enjoy an occasional launch at home. I wonder how many HPR guys launch lots of tiny rockets as well. The trouble is that there aren't as many component options for small rockets without buying bundles of parts. For HPR stuff I can go to LOC or other places and get one tube, one this, one that, etc. Nose cones are limited on little rockets too, it seems. I made the Angry Pickle nose out of blue foam using my drill as a lathe, and then coated it with epoxy to toughen it up, but that's hardly an ideal solution.

    Anyway, that's my LPR plans. The first one that I designed for this order is a mini version of my old L1 build in style. I might try to make a little Nike Smoke rocket with one of the conical nose cones in the pack, though the cone is on the short side I think. Designing my own kit just seems better suited for me than getting a pre-packaged "slap this together tonight and fly tomorrow" kit from a distributor.

    Anyway, no real questions, just hoping something here stirs up a conversation. I'm new so I mainly want to meet some people here and talk about rocket things. My dream is to build and launch a sounding rocket at Black Rock someday, and I also just started a programming project to make my own flight simulator for hobby rocketry.
     
  2. Mar 24, 2020 at 3:39 AM #2

    Nytrunner

    Nytrunner

    Nytrunner

    Master of Rivets

    Joined:
    Oct 15, 2016
    Messages:
    5,902
    Likes Received:
    1,503
    Gender:
    Male
    Location:
    Huntsville AL
    I like rockets of all sizes!

    I may be L2, but ive got a bunch more low and mid power than high power rockets, theyre easier to store, cheaper to fly, and you dont have to call ATC
     
  3. Mar 24, 2020 at 3:49 AM #3

    Off Grid Gecko

    Off Grid Gecko

    Off Grid Gecko

    Active Member

    Joined:
    Tuesday
    Messages:
    28
    Likes Received:
    2
    Gender:
    Male
    Location:
    Southern Missouri
    Forgive me, I had to add apostrophes to the quote, lol. It's late.
    Good to hear. I've been wondering lately how much most HPR guys actually fly smaller rockets. For some reason I can picture guys that only launch at their club dates, but that doesn't seem possible with a hobby. Cheap to fly is right. I think that's my main reason for wanting to build some. I tell myself it's to get more "recent experience" with rocketry, flying in light wind, etc., but it's really because they are cheap and fun. Plus I can ship motors to my PO box (I don't have a mailbox and I'm at work when the UPS guy drives through anyway, not that he can find me).
     
  4. Mar 24, 2020 at 11:05 AM #4

    K'Tesh

    K'Tesh

    K'Tesh

    OpenRocket Chuck Norris

    Joined:
    Mar 27, 2013
    Messages:
    13,511
    Likes Received:
    614
    Problem with little rockets and cert flights is the likelihood of losing it.

    I would recommend for the cheap route to use a mailing tube for the body tube and foam for the nosecone.

    Oh and Welcome to TRF!
     
  5. Mar 24, 2020 at 11:48 AM #5

    Off Grid Gecko

    Off Grid Gecko

    Off Grid Gecko

    Active Member

    Joined:
    Tuesday
    Messages:
    28
    Likes Received:
    2
    Gender:
    Male
    Location:
    Southern Missouri
    I might just buy a kit this go round for the L1. Save up and grab one. I do keep mailing tubes when I can get them with the idea of building a rocket. For that build I wanted to do it all myself to see if I could. I actually molded the nose out of the kraft tube for the rocket and then filled it with foam and layered the top with so much stuff I can't even recall all the steps until it was smooth and correct.
    This time....fiberglass nose cone. lol. If I don't get a kit I'll build the rest with phenolic and plywood, most likely. Whatever size motor I use, I may just get a 48" section of engine tube and turn the rest into a minimum diameter MPR for fun.
     
  6. Mar 24, 2020 at 12:03 PM #6

    Greg Furtman

    Greg Furtman

    Greg Furtman

    Forum Supporter TRF Supporter

    Joined:
    Nov 10, 2018
    Messages:
    681
    Likes Received:
    273
    Gender:
    Male
    Location:
    Webster, Wisconsin
    I've been flying LPRs for years. I got into HPR a few years ago & although it's a gas it does get spendy. I'm still making LPRs & getting into MPRs. Been saving cardboard tubes over the years mainly from plotters.

    One thing that has really helped me with design is OpenRocket. You can design & then choose different motors and run flight simulations. You can get it here.

    https://www.rocketryforum.com/threa...d-mac-to-solve-all-your-java-problems.143540/

    @K'Tesh is the OR guru. Check out his tutorials here on TRF.
     
  7. Mar 24, 2020 at 12:06 PM #7

    K'Tesh

    K'Tesh

    K'Tesh

    OpenRocket Chuck Norris

    Joined:
    Mar 27, 2013
    Messages:
    13,511
    Likes Received:
    614
    The Binder Design Excel is a good one for getting on.
     
  8. Mar 25, 2020 at 12:18 AM #8

    Off Grid Gecko

    Off Grid Gecko

    Off Grid Gecko

    Active Member

    Joined:
    Tuesday
    Messages:
    28
    Likes Received:
    2
    Gender:
    Male
    Location:
    Southern Missouri
    That's a funny looking 4" rocket, looks like a giant size Estes model. I do like the longer version better. I think I have my heart set on one of the HyperLOC models though for an L1 kit, or perhaps a MadCow. LOC and MadCow seem to design profiles that I enjoy looking at. Thanks so much for the rec though. I googled it and found a company that I was previously unfamiliar with.

    Greg Furtman:
    I have OpenRocket, but for some reason cannot get it to work on either Java8 or the current version. I have an .exe file too, but I need to figure out how to configure WINE to run it, as I haven't used Windows software in quite a while. I thought about getting Sun Java 6 but don't like giving out my information so quickly just to download something, especially something that is so dated. I'm not sure what's up with that, I assume it's some kind of rights issue before Java mutated.
    The Cambridge ripoff of it doesn't work at all for me at the moment.
    After thinking about it for a bit I decided to make my own sim, and make it my way, so I've been spending a little time here and there to set that up. With any luck, I'll have an alpha version soon and then I can start adding features to it. It focuses on a more visual approach without as much fiddling in little numbers. Obviously, there will still be numbers and fiddling, but I want to reduce it, and I have some cool ideas for doing that, but making a working prototype must come first, as with everything.
    I have a physics degree, so I'm not plopping down $140 for RockSim when I can make a spreadsheet that gets me close enough, that much I know for sure.
     
  9. Mar 25, 2020 at 12:21 AM #9

    Off Grid Gecko

    Off Grid Gecko

    Off Grid Gecko

    Active Member

    Joined:
    Tuesday
    Messages:
    28
    Likes Received:
    2
    Gender:
    Male
    Location:
    Southern Missouri
    Sorry to post twice so quickly, but in the meantime recommendations on some cheapie LPR kits, or even MPR, would be cool. There should be some $10 rocket kits out there somewhere, right? I don't require decals or painted parts.
     
  10. Mar 25, 2020 at 12:21 AM #10

    Nytrunner

    Nytrunner

    Nytrunner

    Master of Rivets

    Joined:
    Oct 15, 2016
    Messages:
    5,902
    Likes Received:
    1,503
    Gender:
    Male
    Location:
    Huntsville AL
    Any precedent here @neil_w?
     
  11. Mar 25, 2020 at 12:39 AM #11

    neil_w

    neil_w

    neil_w

    Hunkered down TRF Supporter

    Joined:
    Jul 14, 2015
    Messages:
    7,659
    Likes Received:
    1,505
    Location:
    Northern NJ
    Hmm. Gecko I assume you’re running Linux? May I ask which distro?

    Openrocket should run under Java 8 (nothing later, yet). What exactly happens when you try to run it?

    I’ve not heard of anyone running it under WINE, since it should never be necessary.
     
  12. Mar 25, 2020 at 12:51 AM #12

    Bat-mite

    Bat-mite

    Bat-mite

    Rocketeer in MD

    Joined:
    Dec 5, 2013
    Messages:
    10,534
    Likes Received:
    1,349
    Gender:
    Male
    Location:
    Maryland
    Welcome to the madness, Mr. Gecko.
     
    Greg Furtman likes this.
  13. Mar 25, 2020 at 2:37 AM #13

    Off Grid Gecko

    Off Grid Gecko

    Off Grid Gecko

    Active Member

    Joined:
    Tuesday
    Messages:
    28
    Likes Received:
    2
    Gender:
    Male
    Location:
    Southern Missouri
    I posted a picture. Same that happens when I try version 11. It's not a big deal. I had it working on this laptop before I updated (Linux Mint), so I have some rocket files saved. Nice to meet you, btw. I was quite enjoying your software when I was doing rocket stuff before. I'm still working on the UI and the models for my simulator, so if it's okay I might collaborate with you when I start coding the drag model for my own sim (when/if/etc). Maybe we can compare notes.
    In the meantime, if you can spot an obvious problem or want more input from me on this little glitch just let me know. I'm using OpenJDK Java 8 to try running the file.

    Oh, this showed up in the bug report:
    97 0.967 STDERR (SwingExceptionHandler.java:49) Caused by: java.lang.ClassNotFoundException: javax.script.ScriptEngineFactory
     

    Attached Files:

  14. Mar 25, 2020 at 4:22 AM #14

    OverTheTop

    OverTheTop

    OverTheTop

    Well-Known Member

    Joined:
    Jul 10, 2007
    Messages:
    3,237
    Likes Received:
    734
    Gender:
    Male
    Location:
    Melbourne Australia
    Welcome aboard Mr Gecko. Lots of interesting things and friendly people here.

    It's funny, but I usually fly L motors and above, or D motors. Mostly nothing in between. Flying the small stuff makes for a very quick prep and stress free flights :).
     
  15. Mar 25, 2020 at 10:49 AM #15

    Off Grid Gecko

    Off Grid Gecko

    Off Grid Gecko

    Active Member

    Joined:
    Tuesday
    Messages:
    28
    Likes Received:
    2
    Gender:
    Male
    Location:
    Southern Missouri
    Have a small stockpile of D motors do you? :p Do you launch your little ones from an 1/8" rail? I started my current setup with 1/4" bar stock so even my little A rockets get a 1/4" lug. Trying to picture a little rocket with 1515 rail buttons.
     
  16. Mar 25, 2020 at 10:53 PM #16

    OverTheTop

    OverTheTop

    OverTheTop

    Well-Known Member

    Joined:
    Jul 10, 2007
    Messages:
    3,237
    Likes Received:
    734
    Gender:
    Male
    Location:
    Melbourne Australia
    5/32" actually!!! :p

    Last year was a bit slow for me, with only one HPR flight. Two stage, O3400 to M2020. There was about six D motor flights as well, but the impulse from them is down in the noise.
     
  17. Mar 25, 2020 at 11:18 PM #17

    neil_w

    neil_w

    neil_w

    Hunkered down TRF Supporter

    Joined:
    Jul 14, 2015
    Messages:
    7,659
    Likes Received:
    1,505
    Location:
    Northern NJ
    Um, it's not "my" software. OpenRocket is originally by Sampo Niskanen and subsequently developed and maintained by an evolving team, of which I am one. The code is all on Github.

    We're always looking for more developers, so if you're into this sort of thing please consider joining.

    Sorry, no clue yet.
     
  18. Mar 26, 2020 at 12:49 AM #18

    Off Grid Gecko

    Off Grid Gecko

    Off Grid Gecko

    Active Member

    Joined:
    Tuesday
    Messages:
    28
    Likes Received:
    2
    Gender:
    Male
    Location:
    Southern Missouri
    I may take a peek at some point. I'm coding the engine for mine in Godot Engine. These days I stick to HTML, PHP, etc for webpage stuff, tinker with Blender, and do most of my design in Godot. Haven't done much lower level stuff like C++ since I was in college, and I don't think I've ever coded in Java (though I assume it isn't much different from any other language). I did a little unity scripting, mostly guessing and letting the real coders do sanity checks, for the Kerbal modders when I had an idea of how to implement cool features. Mostly just do stuff on my own though. Too many ideas and not enough time, if I could hire my own dev team for my projects I would. I don't think there's anything I could really contribute to OR, it ticks all the boxes for what it's designed to do. My little pet project is basically just a 3D version of the same concept that could eventually let you see you simulated rocket take off, do cool paint jobs, and even become a fun video game at a certain point. Not sure where it's going but I'm basically making it for me.
     
  19. Mar 26, 2020 at 1:03 AM #19

    crossfire

    crossfire

    crossfire

    Lifetime Supporter TRF Lifetime Supporter

    Joined:
    Jan 16, 2011
    Messages:
    3,778
    Likes Received:
    268
    Welcome to TRF
     
  20. Mar 26, 2020 at 1:06 AM #20

    PXR5

    PXR5

    PXR5

    Starship Hijacker TRF Supporter

    Joined:
    Jul 3, 2015
    Messages:
    381
    Likes Received:
    112
    Gender:
    Male
    Location:
    Monroe NC
    Welcome aboard :)
     
  21. Mar 26, 2020 at 2:10 AM #21

    Off Grid Gecko

    Off Grid Gecko

    Off Grid Gecko

    Active Member

    Joined:
    Tuesday
    Messages:
    28
    Likes Received:
    2
    Gender:
    Male
    Location:
    Southern Missouri
    Thanks everyone for the welcome messages. Glad to be in a place where I can talk about one of my passions with people who know what I'm talking about. Most folks have some very specific yet horribly inaccurate ideas about model rocketry and amateur rocketry. Guess that's why we have a forum. Just found out Apogee is closed down for coronavirus, so I have an excuse to wait for a couple more paychecks before placing my order. Happy to save cash but sad to not have a rocket to work on. Oh well.
     
  22. Mar 26, 2020 at 8:13 PM #22

    BABAR

    BABAR

    BABAR

    Builds Rockets for NASA TRF Lifetime Supporter TRF Supporter

    Joined:
    Aug 27, 2011
    Messages:
    5,089
    Likes Received:
    766
    Have you considered building "inside the box"? Lot's of long skinny cardboard boxes (typical ones are the ones that they ship big plastic dry erase wall calendars in.) "Why build square?" you ask? The reason is that making nose cones (technically pyramids) for square cross section rockets is cheap and easy. You will need to make your own centering rings, can be done with foam board (also cheap). Do your "through the wall" fins on the motor mount before insertion, cut your slots all the way to the tail end of your box body tube, slide it into place and seal off the gaps at the base of the box.
     
  23. Mar 26, 2020 at 8:54 PM #23

    ebruce1361

    ebruce1361

    ebruce1361

    The man with the plan. And some duct tape.

    Joined:
    May 14, 2018
    Messages:
    333
    Likes Received:
    136
    Location:
    Pinellas County, Florida
    There's a lot to be said for recycled materials that can be had for cheap. Right now, I'm wrapping up a build made from three tubes that bottles of scotch came in, the fabric from a broken umbrella for the parachute, and an Easter egg for the nose cone. If you don't consider the fact that I actually bought the scotch, the cost of the rocket's materials is likely under $25. Try going to your local liquor store and see if they have any cardboard tubes going into the trash, grab up Easter eggs here in a few weeks when they go on sale right after the holiday, and look at single-use plastic wine glasses for more parabolic nose cones. There are cheap, even free rocket materials EVERYWHERE!

    20200322_113519.jpg
     
  24. Mar 26, 2020 at 9:58 PM #24

    Off Grid Gecko

    Off Grid Gecko

    Off Grid Gecko

    Active Member

    Joined:
    Tuesday
    Messages:
    28
    Likes Received:
    2
    Gender:
    Male
    Location:
    Southern Missouri
    BABAR, for sure have thought about a square tube for fun. Might do it sometime if I'm bored. Would be interesting to do a round and a square with the same cross-sectional area and compare the flight characteristics, actually, again, just for fun and the result may end up surprising me. It's name comes built in, the Obelisk!

    ebruce1361 (is that the year you were born? are you a vampire?) Kudos on the build. I've made plenty from stuff laying around, but I find myself buying lots of "junk" to make rockets with and then the sizes are weird and stuff doesn't match up. My last one cost nothing but the motor, but the one prior to that made me wonder how much money I would have saved by purchasing a LOC fiberglass kit from the start, lol. Cause I bought everything: different glues with various properties, a roll of craft paper, cardstock, some easter eggs, though plastic champagne glasses must have been in short demand that month, couldn't find one anywhere of the right shape, saved bits of round plastic from the printer tape at work, cut apart beer cans and deodorant bottles. For a brief while, everything looked like a rocket part, but most were mismatched sizes, which could be fun too, but I'm usually going for a cleaner styling.
    Love the brandy rocket. What motor are you planning to run on her?
     
  25. Mar 27, 2020 at 1:43 PM #25

    ebruce1361

    ebruce1361

    ebruce1361

    The man with the plan. And some duct tape.

    Joined:
    May 14, 2018
    Messages:
    333
    Likes Received:
    136
    Location:
    Pinellas County, Florida
    Yes. I am a vampire. (hissss)

    Actually, 1361 was the U.S. FIRST robotics team number I was on in high school. The team has since gone defunct, but that group of kids and those after school and weekend sessions of building a robot in six weeks were some of the most influential of my life. I even met my wife through that team. :D

    When it comes to size inconsistencies, I just managed to get lucky with the scotch tubes and that one Easter egg that fit perfectly. Nose cones are the most difficult thing to size to scavenged tubes, but if you can get an "almost" fit, you can often play with it and add layers of paper mache or foam to cut to size and sculpt to your ideal shape. Everything else is pretty easy. Centering rings are a sinch if you have a compass/protractor set and a belt sander.

    As for the above tribute to my preferred libation, it's designed to fly on a 4X cluster of 24mm Aerotech motors. They have to be Aerotech because I designed this with no internal thrust rings in the motor tubes, so it can accommodate motors of different lengths, but they have to have the wider nozzle end unlike black powder motors. (I suppose I could also use Cesaroni, but I don't have any experience with them as yet) For the initial test flight, I might do just two E15-7Ws with no payload, but it's ultimately designed to carry three shots of scotch to about 1500ft on two E15-7Ws and two E30-7Ts. Once I get my level-1 cert, I can really give it a kick in the pants with 4X F44-8Ws! If you want to see more of this project, here's my build thread:
    https://www.rocketryforum.com/threads/care-for-some-scotch.157850/
     
  26. Mar 27, 2020 at 1:54 PM #26

    neil_w

    neil_w

    neil_w

    Hunkered down TRF Supporter

    Joined:
    Jul 14, 2015
    Messages:
    7,659
    Likes Received:
    1,505
    Location:
    Northern NJ
    It is common practice to create a thrust ring on the back of Estes motors by wrapping some layers of tape (masking or blue tape, whatever) around the last 1/8" or so. Wrap the tap around, and then trim off the overhang with a knife. It's a bit of effort but it works fine.

    Scroll down in this (long!) Rocket N00b post to see a perfect example. http://rocketn00b.blogspot.com/2015/05/mid-power-building-quest-big-dog-part_20.html

    Apologies if I misunderstood what you were saying.
     
    ebruce1361 likes this.
  27. Mar 27, 2020 at 2:26 PM #27

    ebruce1361

    ebruce1361

    ebruce1361

    The man with the plan. And some duct tape.

    Joined:
    May 14, 2018
    Messages:
    333
    Likes Received:
    136
    Location:
    Pinellas County, Florida
    No apologies necessary, nor did you misunderstand. I did think about wrapping some D12-3s thusly, but I am worried about not having enough power. Although, that could be an option for a test flight with no payload.

    I will say that I have an ulterior motive for wanting the combination of E15-7w and E30-7T motors. For an instant, there will be a mix of white and blue flames under the rocket. That may or may not have anything to do with the flag of Scotland. :rolleyes::D
     
  28. Mar 27, 2020 at 2:54 PM #28

    neil_w

    neil_w

    neil_w

    Hunkered down TRF Supporter

    Joined:
    Jul 14, 2015
    Messages:
    7,659
    Likes Received:
    1,505
    Location:
    Northern NJ
    I didn't realize the E30s were blue, I have my first few waiting to be used (maybe for a long time :rolleyes:). Caution is advised if mixing E15 and E30; I've read here many times that white lightning in the E15 is comparatively hard to start. I haven't had any problems with them but then again I haven't tried to cluster them.
     
  29. Mar 27, 2020 at 3:29 PM #29

    ebruce1361

    ebruce1361

    ebruce1361

    The man with the plan. And some duct tape.

    Joined:
    May 14, 2018
    Messages:
    333
    Likes Received:
    136
    Location:
    Pinellas County, Florida
    @neil_w They do have the blue propellant formula, but I'll be honest and say that I have never seen it. All of the rockets I have flown on single E30s moved so fast that the motor had burned out by the time I could focus on the exhaust plume. Maybe I should set up a high-speed video from my phone to catch the launch of my next one.

    I, too have yet to have an issue with E15s instantly lighting, but I will be assembling a companion cluster whip just for this rocket that will have extended leads just in case an igniter needs additional milliseconds to fire up. In the event one of them doesn't light, the rocket will still get decent altitude on three or even two motors (although with a full payload, a 7 second delay might be cutting it close with only two motors; I might have to sim this contingency).

    After the primary flight with the scotch, this rocket will serve to be a good sized experiment payloader. One thing I have wanted to play with is "cluster insurance". The basic idea is a cluster is wired up with only one motor actually started from the launch controller. The controller leads are clipped to that motor's igniter as well as a second pair of wires in parallel going into an electronics bay in the rocket. Those will energize a relay that connects an onboard battery pack to the other igniters. The idea is that while all but one of the first stage motors are *technically* started with onboard power, the system isn't engaged unless a traditional controller actually triggers the launch. I suppose I could have the controller leads only power the relay mechanism, but I think it would be in good form to have at least one motor actually start solely because the controller did it. I figure this rocket would be a good candidate to have such hardware installed and tried out!

    Anyway, didn't mean to hijack your thread, @Off Grid Gecko ! Keep us posted on projects you start; can't wait to see what you have in store for us!
     
    neil_w likes this.
  30. Mar 27, 2020 at 6:06 PM #30

    Nytrunner

    Nytrunner

    Nytrunner

    Master of Rivets

    Joined:
    Oct 15, 2016
    Messages:
    5,902
    Likes Received:
    1,503
    Gender:
    Male
    Location:
    Huntsville AL
    For lower power Blue Thunder motors (below G80 basically), you may get burnout near rail exit, and the blue flame being most visible at higher thrust/pressure, that may be done before it's even off the rail. I want to say things are similar for CTI's Blue Streak, I just haven't paid as close attention

    Example, my RWBCC explorer on a D15 Blue Thunder. Do you see blue? I don't
    (For contrast, there's a photo somewhere of our treasurer's Leviathan with a G80 spills its flame over the deflector in a beautiful blue. I wonder who has that)

    [​IMG]
     
    OverTheTop and ebruce1361 like this.

Share This Page

Group Builder