Draggster - The Slowest Rocket Ever

Discussion in 'Low Power Rocketry (LPR)' started by BlastoffDFW, Oct 9, 2018.

  1. Oct 9, 2018 #1

    BlastoffDFW

    BlastoffDFW

    BlastoffDFW

    Member

    Joined:
    Jan 17, 2018
    Messages:
    16
    Likes Received:
    0
    I have an upcoming launch at a school with a small field. Kids will be launching on 1/2A6-2, but I'm hoping to demo something with a little more noise. So...

    I'm designing an extremely slow rocket built on 2 x Estes BT-80 tubes (1 for body, 1 for tube fins). It currently sims out to about 42 meters apogee on an Aerotech F44W-4.

    Question:
    Has anybody tried creating tube fins that are entirely closed (capped at both ends)? Any reason this wouldn't be safe?
     

    Attached Files:

  2. Oct 9, 2018 #2

    Zeus-cat

    Zeus-cat

    Zeus-cat

    Well-Known Member

    Joined:
    Mar 14, 2009
    Messages:
    3,581
    Likes Received:
    48
    If they are capped then they aren't fins. They would create a lot of drag which SHOULD keep it stable. I have several Newway Dare 2 B Square (18mm) rockets and they are very stable. Essentially, they are a flat plate with a motor underneath. The don't go very high, but make a fair amount of noise and smoke on a C6.

    However, I would not launch something like you are proposing near a crowd until I had tested it a few times under various conditions to verify that it really was stable. And if it is as slow as you indicate any wind or other issue could cause it to veer off course. Not a good idea with lots of kids around.

    A saucer or the kit I mentioned may be a better idea.
     
  3. Oct 9, 2018 #3

    UP IN SMOKE

    UP IN SMOKE

    UP IN SMOKE

    Member

    Joined:
    Oct 8, 2018
    Messages:
    5
    Likes Received:
    0
    Location:
    Earth
    Pretty new to this addiction but I vote open vs. capped simply because of drag. But I might also be worried that the whole "fincan" or at least part of it might umm, separate from the body if capped! Anyway it looks nice and will be something to see launch. 42 meters per second (roughly)... nice!
     
  4. Oct 9, 2018 #4

    dhbarr

    dhbarr

    dhbarr

    Amateur Professional

    Joined:
    Jan 30, 2016
    Messages:
    4,332
    Likes Received:
    91
    It's a good question. My guesses, from least drag to most:
    - totally open
    - both ends capped
    - top only capped
    - bottom only capped
    - bulkhead ~2/3 distance from the top of the tubefin to the bottom
     

Share This Page