Remember those little water/air pressure rockets? Steroid Time!
Close
Login to Your Account
Page 1 of 5 123 ... LastLast
Results 1 to 20 of 97
  1. #1
    Join Date
    Dec 2008
    Location
    W. Mich
    Posts
    354
    Post Thanks / Like
    Likes (Given)
    103
    Likes (Received)
    143

    Default Remember those little water/air pressure rockets? Steroid Time!

    Here is the test stand for testing the rocket. There are five 4,500 psi tanks, three and two connected separately. All tig welded steel tube. Most are aware that an arc scratch makes a high pressure tank worthless. When I called the welding supply they said rental only on a 4,500 tank. I asked if I paid my rent on time every month, would they ever want to see their tank? This led to some laughs, then I found some from a paintball guy to buy. Before you think I am insane for welding on a high pressure cylinder, I'll explain in further pictures. This set up is a test for a carbon fiber tank that is going into a hydroplane. I put a two foot deep heavily re-barred pit for cement. The frame is bolted with fourteen grade eight one inch bolts to fourteen 3" diameter steel bars eighteen inches long with plates welded to the bottoms. There is roughly 14,000 pounds of cement-but-I have now seen 9,500 lbs of thrust so far and if I were to pressurize to the maximum 4,500 psi it would exceed the weight of the cement in pushing thrust. Of course it's not directly lifting so it's not a problem, but I'll never push it that far anyways.

    rocket-2.jpgrocket-8.jpgrocket-5.jpgrocket-7.jpg

    The hole in the cylinder to connect tanks was cut on a cnc mill, the slugs that were removed were EDM'ed to make test bars to be tested on my tensile machine. The test bars were tested as is and after welding to insure strength at the welded joints. The tank is rated for 4,500 lbs, tank test pressure 6,750 psi. Tensile testing showed the burst pressure of the tank was at least 9,000 psi and more likely closer to 10,000 psi. All connecting tubes were 4130 chrome moly steel.

  2. #2
    Join Date
    Jan 2005
    Location
    Houston
    Posts
    6,245
    Post Thanks / Like
    Likes (Given)
    788
    Likes (Received)
    3008

    Default

    What's the question?

  3. Likes digger doug liked this post
  4. #3
    Join Date
    May 2019
    Country
    UNITED STATES
    State/Province
    Michigan
    Posts
    1,436
    Post Thanks / Like
    Likes (Given)
    398
    Likes (Received)
    640

    Default

    Do you have a death wish?

  5. #4
    Join Date
    Dec 2008
    Location
    W. Mich
    Posts
    354
    Post Thanks / Like
    Likes (Given)
    103
    Likes (Received)
    143

    Default

    This is the destination for the rocket. 17 foot and only 240 pounds, mostly carbon fiber never in water since new.
    rocket-boat.jpg rocket-1.jpg rocket-6.jpg

    This gauge with telltale needle shows thrust. The hydraulic cylinder is bored to a diameter that will read directly in lbs of thrust. I have seen 9,500 on a different pressure gauge, I out grew the 5,000 gauge after several tests. I will post some videos of a few tests soon. Both with air pressure over water and air pressure only. The rapidly escaping air chills the surrounding air and there is always a wide variation in the fog effect through the nozzle. High humidity and a high dew point make for quite a show. Unfortunately I didn't have video running for some exceptional firings.

  6. #5
    Join Date
    Sep 2006
    Location
    Sacramento County, California
    Posts
    3,970
    Post Thanks / Like
    Likes (Given)
    2487
    Likes (Received)
    1415

    Default

    Nothing new under the sun. They were doing this and more at Rocketdyne, Division of NAA when I worked there years ago. The only thing I'm wondering is why. And, yes, welding on a pressure vessel is a no-no.

  7. Likes digger doug liked this post
  8. #6
    Join Date
    Dec 2008
    Location
    W. Mich
    Posts
    354
    Post Thanks / Like
    Likes (Given)
    103
    Likes (Received)
    143

    Default

    Quote Originally Posted by GregSY View Post
    What's the question?
    My question is, do I have a volunteer driver out there, the lighter the better?

  9. #7
    Join Date
    Dec 2008
    Location
    W. Mich
    Posts
    354
    Post Thanks / Like
    Likes (Given)
    103
    Likes (Received)
    143

    Default

    Quote Originally Posted by Newman109 View Post
    Nothing new under the sun. They were doing this and more at Rocketdyne, Division of NAA when I worked there years ago. The only thing I'm wondering is why. And, yes, welding on a pressure vessel is a no-no.
    I'll have to disagree about welding no-no. I worked in a mechanical testing aerospace facility for several years and did my homework before going ahead with this. The finished product, after welding easily passed a hydro certification, seeing as though all my work was over kill on materials and welding technique.

  10. Likes 4GSR liked this post
  11. #8
    Join Date
    Oct 2005
    Country
    CANADA
    State/Province
    Ontario
    Posts
    1,278
    Post Thanks / Like
    Likes (Given)
    319
    Likes (Received)
    460

    Default

    Quote Originally Posted by Bluechipx View Post
    My question is, do I have a volunteer driver out there, the lighter the better?


    Is this guy available? Lot's of experience!



  12. Likes awander, thomj, Larry Dickman, 4GSR, DrHook and 13 others liked this post
  13. #9
    Join Date
    Sep 2006
    Location
    Sacramento County, California
    Posts
    3,970
    Post Thanks / Like
    Likes (Given)
    2487
    Likes (Received)
    1415

    Default

    Quote Originally Posted by Bluechipx View Post
    I'll have to disagree about welding no-no. I worked in a mechanical testing aerospace facility for several years and did my homework before going ahead with this. The finished product, after welding easily passed a hydro certification, seeing as though all my work was over kill on materials and welding technique.
    OK. whatever you say.................

  14. Likes digger doug liked this post
  15. #10
    Join Date
    Dec 2008
    Location
    W. Mich
    Posts
    354
    Post Thanks / Like
    Likes (Given)
    103
    Likes (Received)
    143

    Default

    https://photos.google.com/share/AF1Q...xnc21IcUVCYUdR

    Here is a 1,200 psi test that showed 3,500 pounds on the thrust gauge. You might have to double click the picture to start video.

  16. Likes dalmatiangirl61, empwoer liked this post
  17. #11
    Join Date
    Oct 2005
    Country
    UNITED STATES
    State/Province
    Pennsylvania
    Posts
    17,720
    Post Thanks / Like

    Default

    Quote Originally Posted by Bluechipx View Post
    I'll have to disagree about welding no-no. I worked in a mechanical testing aerospace facility for several years and did my homework before going ahead with this. The finished product, after welding easily passed a hydro certification, seeing as though all my work was over kill on materials and welding technique.
    Did it pass for repeated reversal loading ?
    How many cycles ?

    what is failure mode ?

    There is a fair number of High pressure engineering firms here in Erie, and I have seen what a couple of test chambers look like.

  18. #12
    Join Date
    Jan 2014
    Location
    Temecula, Ca
    Posts
    3,276
    Post Thanks / Like
    Likes (Given)
    1396
    Likes (Received)
    4259

    Default

    Quote Originally Posted by Bluechipx View Post
    My question is, do I have a volunteer driver out there, the lighter the better?
    oops, your a little too late to get this guy

    YouTube

  19. Likes DrHook, Garwood, empwoer liked this post
  20. #13
    Join Date
    Sep 2006
    Location
    Sacramento County, California
    Posts
    3,970
    Post Thanks / Like
    Likes (Given)
    2487
    Likes (Received)
    1415

  21. #14
    Join Date
    Feb 2014
    Location
    FL
    Posts
    3,433
    Post Thanks / Like
    Likes (Given)
    11703
    Likes (Received)
    3933

    Default

    Quote Originally Posted by Bluechipx View Post
    My question is, do I have a volunteer driver out there, the lighter the better?
    5'3, 150ish lbs.

    I'm in.

  22. Likes DrHook, Cole2534, bryan_machine liked this post
  23. #15
    Join Date
    Jan 2007
    Location
    Norfolk, UK
    Posts
    19,859
    Post Thanks / Like
    Likes (Given)
    15301
    Likes (Received)
    15576

    Default

    Another organ donor project.

  24. #16
    Join Date
    May 2019
    Country
    UNITED STATES
    State/Province
    Michigan
    Posts
    1,436
    Post Thanks / Like
    Likes (Given)
    398
    Likes (Received)
    640

    Default

    Quote Originally Posted by Limy Sami View Post
    Another organ donor project.
    Been quite a few lately.

    Must be the virus has mutated and is affecting brain cells, too......

  25. Likes Limy Sami liked this post
  26. #17
    Join Date
    Oct 2013
    Location
    st,louis mo
    Posts
    686
    Post Thanks / Like
    Likes (Given)
    1
    Likes (Received)
    356

    Default

    EVERYTHING IS A NO NO. This is a VERY INTERESTING THREAD. Try to be a bit safer. The blast that you did show,looks strong enough to pick up a brick and throw it.You have inspired me to post some of my projects that will make the safety police go crazy also.Good luck. Edwin Dirnbeck

  27. Likes dkmc, pb57 liked this post
  28. #18
    Join Date
    Jan 2011
    Location
    BFE Nevada/San Marcos Tx
    Posts
    1,457
    Post Thanks / Like
    Likes (Given)
    1574
    Likes (Received)
    839

    Default

    Quote Originally Posted by Bluechipx View Post
    My question is, do I have a volunteer driver out there, the lighter the better?
    I know someone that might be interested, if you are serious. No experience with boats that I know of, nerves of steel in a car, and a stack of trophies to prove it. Its not me.

    Cool project!

  29. #19
    Join Date
    Mar 2005
    Country
    UNITED STATES
    State/Province
    Indiana
    Posts
    4,760
    Post Thanks / Like
    Likes (Given)
    1256
    Likes (Received)
    1191

    Default

    Erm, so... Judging by the video, this looks more like an explosion rather than a controlled release. So is there a different approach for running this "vehicle" than used in the test? Otherwise it will probably kill the driver as soon as the pressure is released. Is the plan to pressurize tanks to 4,500 and release at 1,200? Will be tough to get enough flow with a regulator if so. Tough to get much thrust time if no.

  30. #20
    Join Date
    Oct 2009
    Location
    Oregon
    Posts
    4,876
    Post Thanks / Like
    Likes (Given)
    5277
    Likes (Received)
    2514

    Default

    I think you should make a video of one on a 50' steel cable tether in your backyard.


Tags for this Thread

Bookmarks

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •