Star Orbiter G80T...Supersonic?

Discussion in 'Mid Power Rocketry (MPR)' started by ebman159, Jul 23, 2019.

Help Support The Rocketry Forum by donating:

  1. Aug 9, 2019 #61

    ebman159

    ebman159

    ebman159

    Well-Known Member

    Joined:
    Jul 23, 2019
    Messages:
    53
    Likes Received:
    8
    Gender:
    Male
    It’s 108.6 grams/3.8 oz right now. That’s after all epoxy/glues and structural components. Which sounds about right because sim says 240g with the engine and electronics.
     
    ChicagoDave likes this.
  2. Aug 10, 2019 #62

    Wallace

    Wallace

    Wallace

    Sponsor TRF Sponsor TRF Supporter

    Joined:
    Feb 16, 2017
    Messages:
    2,148
    Likes Received:
    369
    Cool, now make it happen and don't forget to post results, good, bad or anywhere in between. Personally I think it is possible, may just take more than one iteration but seeing as how inexpensive they are....
     
  3. Oct 6, 2019 #63

    ebman159

    ebman159

    ebman159

    Well-Known Member

    Joined:
    Jul 23, 2019
    Messages:
    53
    Likes Received:
    8
    Gender:
    Male
    So I launched a couple months back and everything went ok except for the fact it landed in the only couple of trees for 3sq mi and it’s too thick on the ground to see where it is, and even if I could see, it would be too high to get it down. I’m reordering everything Monday or Tuesday to try again. As far as I know, the rocket was in tact when I saw it through my binoculars but I could be wrong as it was pretty far away. I’m going to a bigger launch site next time and I’m going to use a longer launch rod. I think the rocket was too unstable when it left the launch rod...I shortened my traditional 5’ to 3’ to avoid whip...I think the ideal launch rod length I found plugging numbers in OpenRocket was around 4-4.5’. I did have retrieval methods in the rocket it was just unlucky that it landed in those trees...it was open space for about a mile and a half except for those. Any tips for the next launch would be greatly appreciated.
    And I am planning to launch by late October...any idea how colder air will affect the rocket and the flight?
     
  4. Oct 7, 2019 #64

    Wallace

    Wallace

    Wallace

    Sponsor TRF Sponsor TRF Supporter

    Joined:
    Feb 16, 2017
    Messages:
    2,148
    Likes Received:
    369
    Rod=no good. Tower or at least fly away guides. A clean launch from a rod is rare..
     
  5. Oct 7, 2019 #65

    Wallace

    Wallace

    Wallace

    Sponsor TRF Sponsor TRF Supporter

    Joined:
    Feb 16, 2017
    Messages:
    2,148
    Likes Received:
    369
    Even a rail w/buttons would at least be more consistent.
     
  6. Oct 7, 2019 #66

    ebman159

    ebman159

    ebman159

    Well-Known Member

    Joined:
    Jul 23, 2019
    Messages:
    53
    Likes Received:
    8
    Gender:
    Male
    I was thinking about fly aways...with how fast this rocket is accelerating off the launch pad, do you think it would be affected by the fly aways?
     
  7. Oct 7, 2019 #67

    Wallace

    Wallace

    Wallace

    Sponsor TRF Sponsor TRF Supporter

    Joined:
    Feb 16, 2017
    Messages:
    2,148
    Likes Received:
    369
    Personally not a fan, they WILL hit something when they come off. Consider 'em the "easiest (though not cheapest) route. If you have or have access to a 3d printer there are Stl. files online to print your own. Someone was working on hollow plastic buttons with a cutter at the top of the rail. Seemed interesting, but still gonna have an affect. Probably best to cobble a simple tower, should have least amount of impact and your rocket can be clean/clear of any guidance bits for super duper sonic speediness...
     
  8. Oct 7, 2019 #68

    retortec

    retortec

    retortec

    Well-Known Member

    Joined:
    Dec 27, 2015
    Messages:
    188
    Likes Received:
    11
    I second some sort of tower. A fly away guide on a rocket that light will be a significant unpredictable mass. The mass will (slightly) impact the acceleration off the pad. More importantly pulling that many G’s will increase the probability of hitting a fin. Larger rockets can power through such an event. The fly away is a much smaller portion of the total launch mass.
     
  9. Oct 8, 2019 #69

    Wallace

    Wallace

    Wallace

    Sponsor TRF Sponsor TRF Supporter

    Joined:
    Feb 16, 2017
    Messages:
    2,148
    Likes Received:
    369
    Some plywood scraps and conduit will work if you don't want to throw $ at it...
     
  10. Oct 8, 2019 #70

    ebman159

    ebman159

    ebman159

    Well-Known Member

    Joined:
    Jul 23, 2019
    Messages:
    53
    Likes Received:
    8
    Gender:
    Male
    Noted.
     
  11. Oct 8, 2019 #71

    ebman159

    ebman159

    ebman159

    Well-Known Member

    Joined:
    Jul 23, 2019
    Messages:
    53
    Likes Received:
    8
    Gender:
    Male
    Sounds like something I could manage.

    For future reference, what’s the best way to shop for a tower?....I’m kinda new to that concept in terms of model rocketry. I’ve done searches and can’t find anything except for Apogee’s tower.
     
  12. Oct 8, 2019 #72

    retortec

    retortec

    retortec

    Well-Known Member

    Joined:
    Dec 27, 2015
    Messages:
    188
    Likes Received:
    11
    image.jpeg From my 1965 Handbook of Model Rocketry. First tower I built from 1/8" plywood. Towers get really expensive. Best bet is to do some searches on the fourm for ideas. Fined a design in your budget and skill level. I bet it will be far better than what you could buy for the same price.
     
    Last edited: Oct 8, 2019
  13. Oct 8, 2019 #73

    ebman159

    ebman159

    ebman159

    Well-Known Member

    Joined:
    Jul 23, 2019
    Messages:
    53
    Likes Received:
    8
    Gender:
    Male
    That’s super helpful!!! Thank you!!!

    How would I go about determining the height? Sims?
     
  14. Oct 8, 2019 #74

    retortec

    retortec

    retortec

    Well-Known Member

    Joined:
    Dec 27, 2015
    Messages:
    188
    Likes Received:
    11
    Use Open Rocket or Rocksim to determine stability at launch. The length of the "launch rod" can be entered in to the simulation. Small Mach Busters have less overall stability as a trade off to lower the drag. I have always used a bit longer tower than needed for such high speed launches to assure stability. If your sims show good stability a shorter tower will work. I have seen effective towers as short as 1.5 the length of the rocket.
     
    Last edited: Oct 8, 2019
  15. Oct 8, 2019 #75

    Wallace

    Wallace

    Wallace

    Sponsor TRF Sponsor TRF Supporter

    Joined:
    Feb 16, 2017
    Messages:
    2,148
    Likes Received:
    369
    Do you have, have access to,or know someone with a 3d printer? https://www.thingiverse.com/thing:2538353 Would probably be the easiest although not cheapest way. If not, I'd be willing to print and ship it for free if you pick up material and shipping costs...All I'd want in return is supersonic data;)
     
    Last edited: Oct 8, 2019
  16. Oct 8, 2019 #76

    Wallace

    Wallace

    Wallace

    Sponsor TRF Sponsor TRF Supporter

    Joined:
    Feb 16, 2017
    Messages:
    2,148
    Likes Received:
    369
  17. Oct 8, 2019 #77

    ebman159

    ebman159

    ebman159

    Well-Known Member

    Joined:
    Jul 23, 2019
    Messages:
    53
    Likes Received:
    8
    Gender:
    Male
    Yes i do have access to a 3D printer!


    Thank you for the links!
     
  18. Oct 8, 2019 #78

    Wallace

    Wallace

    Wallace

    Sponsor TRF Sponsor TRF Supporter

    Joined:
    Feb 16, 2017
    Messages:
    2,148
    Likes Received:
    369
    Cool. It's all downhill from there...
     
  19. Oct 16, 2019 #79

    ebman159

    ebman159

    ebman159

    Well-Known Member

    Joined:
    Jul 23, 2019
    Messages:
    53
    Likes Received:
    8
    Gender:
    Male
    So I kinda skipped the 3D printed part and put this wild contraption together... IMG_1571193825.917665.jpg IMG_1571193859.545945.jpg

    Figured this would do the job. We’re gonna test it this week with a small E engine and see what it does. Seems to fit well.
     
    Tyler P and mbeels like this.
  20. Oct 16, 2019 #80

    Wallace

    Wallace

    Wallace

    Sponsor TRF Sponsor TRF Supporter

    Joined:
    Feb 16, 2017
    Messages:
    2,148
    Likes Received:
    369
    I like it! Nothing better than something you created yourself. Just make sure you strap it down well. Ratchet straps and stakes are your friend.
     
  21. Oct 16, 2019 #81

    Wallace

    Wallace

    Wallace

    Sponsor TRF Sponsor TRF Supporter

    Joined:
    Feb 16, 2017
    Messages:
    2,148
    Likes Received:
    369
    And, consider rotating those angle irons (aluminums?) 180 degrees? Less surface contact = less friction = :)
     
  22. Oct 17, 2019 #82

    retortec

    retortec

    retortec

    Well-Known Member

    Joined:
    Dec 27, 2015
    Messages:
    188
    Likes Received:
    11
    I like it. Be sure the rocket slides freely the entire length of your rails. A little rattle is ok. All the edges that touch the airframe should be smooth and free of defects. I usually go for a 400 grit sand paper in the end. A little car wax and buff finish it off.
     
  23. Oct 17, 2019 #83

    ebman159

    ebman159

    ebman159

    Well-Known Member

    Joined:
    Jul 23, 2019
    Messages:
    53
    Likes Received:
    8
    Gender:
    Male
    Thank you!!
     
  24. Oct 17, 2019 #84

    retortec

    retortec

    retortec

    Well-Known Member

    Joined:
    Dec 27, 2015
    Messages:
    188
    Likes Received:
    11
    I agree with Wallace. Reducing the number of contact points will enhance the efficiency of the tower. Either way be sure you are using the air frame and not the fins for contact points.
     
    Last edited: Oct 17, 2019
    Wallace likes this.
  25. Oct 17, 2019 #85

    ebman159

    ebman159

    ebman159

    Well-Known Member

    Joined:
    Jul 23, 2019
    Messages:
    53
    Likes Received:
    8
    Gender:
    Male
    Yeah...understood. Thank you!
     
  26. Oct 17, 2019 #86

    Wallace

    Wallace

    Wallace

    Sponsor TRF Sponsor TRF Supporter

    Joined:
    Feb 16, 2017
    Messages:
    2,148
    Likes Received:
    369
    Super cool. Now let's see some data..
     
  27. Nov 17, 2019 #87

    ebman159

    ebman159

    ebman159

    Well-Known Member

    Joined:
    Jul 23, 2019
    Messages:
    53
    Likes Received:
    8
    Gender:
    Male
    Alright so I think the group of students I’ve worked with on the project are ready and we’re launching today at ESL-255...it’s a 3 hour drive for us so hopefully it’ll be worth it and we can find it...unlike the last time.


    Hope to see some of y’all there. Have a good day, guys...and thank you so much for your help!!
     
    Tyler P likes this.
  28. Nov 17, 2019 #88

    K'Tesh

    K'Tesh

    K'Tesh

    OpenRocket Chuck Norris

    Joined:
    Mar 27, 2013
    Messages:
    12,918
    Likes Received:
    457
    Sorry I'm a little late to the party here... An idea... to help with the recovery of the electronics should the rocket shred, may I suggest putting in a long, pleated, mylar streamer in the payload bay attached to the sled. Might make finding the expensive small parts easier to find.

    [EDIT] I'm not saying that the streamer should be the method of recovering the payload bay section. It should be inside the payload bay in the event that whatever causes the shred tears the payload section open, scattering the components like the prizes from a pinata.

    Now I'm working on this kit's 'lil sister' (the Hobby Lobby exclusive kit (The Vapor)). So much of the material needed to sim this kit is actually already done. If someone can get me a scan of the fins and decals (along with a ruler for scale), I could whip up a sim for you.
     
    Last edited: Nov 18, 2019
    Wallace likes this.
  29. Nov 17, 2019 #89

    Wallace

    Wallace

    Wallace

    Sponsor TRF Sponsor TRF Supporter

    Joined:
    Feb 16, 2017
    Messages:
    2,148
    Likes Received:
    369
    While I do like the idea, I can't agree with the concept. Yup, lost more small stuff than I'd like to remember, but it's technically preparing to fail..
     
  30. Nov 17, 2019 #90

    ebman159

    ebman159

    ebman159

    Well-Known Member

    Joined:
    Jul 23, 2019
    Messages:
    53
    Likes Received:
    8
    Gender:
    Male
    I can confirm that this is an essential failure set up in a sense. Even with all of my tracking efforts, I think the design works but the rocket goes up almost too high to keep track of, and today it went above the cloud ceiling, meaning we lost track of it and managed to lose it. It’s there somewhere but not that we could find.
     

Share This Page