Summer Build Contest 2017 "Little Davey's Launch Pad."

Discussion in 'Scratch Built' started by Daddyisabar, May 30, 2017.

Help Support The Rocketry Forum by donating:

  1. May 30, 2017 #1

    Daddyisabar

    Daddyisabar

    Daddyisabar

    Well-Known Member

    Joined:
    Jan 23, 2009
    Messages:
    4,285
    Likes Received:
    55
    Gender:
    Male
    Location:
    Littleton Colorado
    Four free sliding motor mounts glued together over a huge launch lug, smashing into a JB Welded cap which in turn launches a tractor motored rocket that looks like a launch pad. Once the thrust backs off the mount can again slide back as needed (or not) for deployment ejection. Once the four chutes are out the mounts can slide back up and smash yet again into the cap stop.

    Yes Mr. RSO, I know it can work. Yes it looks just like a launch pad sitting out there, but there is a sturdy 3/8" launch rod going down the center that is firmly planted in the ground. Yes it looks like little Davey is going to launch yet another seemingly dangerous, clustered and fin less rocket, but in reality it will all become one big tractor motored rocket. Yes, the motors start out near the bottom of the rocket - where they should be - and then slide up and hit what looks like a rod cap carelessly left on the rod, launching a funny looking, tractor motored, flying launch pad abomination, but what fun could be had! Really, when those motors slide up and hit the heavy cap, the CG is super good! Even with the mount sliding back after trust and propellant burn out, it will still have a lot of nose weight an momentum, and just look as those big launch pad fins at the back of the rocket, a picture of stability. Yes, the launch lug and nose weight nut/washer are metal, but I need the metal to make this one work, just like the high power guys need the aluminum tips and fin cans with the big motors. This one is just four wimpy D12-5's. Yes it looks like naughty little Davey is launching an obviously unstable clustered rocket with the safety cap left on, which in turn takes the entire pad into the sky, but that is the whole point of oddroc fun.

    Mindsim, upgraded version, plan print out:
    Launch pad plans.jpg
    The plan has been reviewed by real United Launch Alliance rocket scientist.

    Parts laid out on couch:
    LP 7.jpg
    Notice Estes "yellow 24mm reinforcement tubes" left over from previous builds. All scrap, left over and hardware store sourced parts. Very low budget.
     
  2. May 30, 2017 #2

    TangoJuliet

    TangoJuliet

    TangoJuliet

    Well-Known Member

    Joined:
    Jun 26, 2016
    Messages:
    1,232
    Likes Received:
    3
    :pop: Intrigued.
     
  3. May 30, 2017 #3

    rstaff3

    rstaff3

    rstaff3

    Oddroc-eteer

    Joined:
    Jan 18, 2009
    Messages:
    11,716
    Likes Received:
    7
    Need to use the actual feet from an old estes pad :)
     
  4. May 30, 2017 #4

    Daddyisabar

    Daddyisabar

    Daddyisabar

    Well-Known Member

    Joined:
    Jan 23, 2009
    Messages:
    4,285
    Likes Received:
    55
    Gender:
    Male
    Location:
    Littleton Colorado
    My Bigfoot Pad was given away years ago when I was in College and the neighbor boy wanted it! I do have junk new ones I could glue on but they are a tad heavy and awkward to fly. I will think about it, mindsim the added danger factor.:)
     
  5. May 30, 2017 #5

    Daddyisabar

    Daddyisabar

    Daddyisabar

    Well-Known Member

    Joined:
    Jan 23, 2009
    Messages:
    4,285
    Likes Received:
    55
    Gender:
    Male
    Location:
    Littleton Colorado
    Build pictures from this weekend.

    Motor blocks and yellow reinforcement tubes glued in. AT igniter tubes use for external reinforcement. Nose cones reinforced with CA. 1/4" balsa fins papered. Washer and nut JB welded on. Decided to smear some yellow glue on the rest of the exposed tubing. Poor Boy Phenolic! Not classy Blue Tube, rather, nasty yellow tube. But real strong and light. Used some plastic strakes to fill in some of the gaps.

    Time for paint!

    LP 6.jpg

    LP 3.jpg

    LP 5.jpg

    LP 4.jpg

    LP 2.jpg

    LP 1.jpg
     
  6. May 31, 2017 #6

    BABAR

    BABAR

    BABAR

    Builds Rockets for NASA TRF Lifetime Supporter TRF Supporter

    Joined:
    Aug 27, 2011
    Messages:
    4,346
    Likes Received:
    485
    Very clever and definitely original.
     
  7. May 31, 2017 #7

    Daddyisabar

    Daddyisabar

    Daddyisabar

    Well-Known Member

    Joined:
    Jan 23, 2009
    Messages:
    4,285
    Likes Received:
    55
    Gender:
    Male
    Location:
    Littleton Colorado
    Thanks!
     
  8. May 31, 2017 #8

    Gary Byrum

    Gary Byrum

    Gary Byrum

    Overstable By Design

    Joined:
    Aug 4, 2011
    Messages:
    6,318
    Likes Received:
    182
    Gender:
    Male
    Location:
    Lincolnton NC
    I'll be interested in watching this fly.
     
  9. May 31, 2017 #9

    Daddyisabar

    Daddyisabar

    Daddyisabar

    Well-Known Member

    Joined:
    Jan 23, 2009
    Messages:
    4,285
    Likes Received:
    55
    Gender:
    Male
    Location:
    Littleton Colorado
    It will be a whoosh-slide-bang-pop kind of LPR BP motored flight. I'm sure it will be in the "highly questionable cluster" category so it will have to fly at Tripoli.
     
  10. May 31, 2017 #10

    MCriscione

    MCriscione

    MCriscione

    Well-Known Member

    Joined:
    Jul 9, 2015
    Messages:
    295
    Likes Received:
    0
    I'm watching this build with interest, and also plan on entering the SBC.

    I just wanted to say, please, if you haven't already considered it, be sure to strongly secure the 'cap' of the launch rod. Looking the at pictures is fun and insightful, but only goes so far. I can't tell from your sketch or the parts you laid out, but from the general arrangement, the moving part of your rocket (the 'booster?') wouldn't be stable if free-flying. There's going to be a pretty large impact force when the booster hits the top of that rod. If there was a failure, either of the rod 'cap' or of the booster's themselves, I'd hate to see your booster (or parts of it) go flying off, unstable, potentially causing damage or injury. It sounds like the launch would be at a pad fairly well removed from the flight line and that may provide some protection. On the other hand, if the booster sheds the 'pad' weight, those engines could go quite far. Just something to think on, if you haven't already. If it were me, I'd consider some kind of softener to reduce the impact/impulse at the top of the rod, rather than just a hard stop.
     
  11. May 31, 2017 #11

    Daddyisabar

    Daddyisabar

    Daddyisabar

    Well-Known Member

    Joined:
    Jan 23, 2009
    Messages:
    4,285
    Likes Received:
    55
    Gender:
    Male
    Location:
    Littleton Colorado
    The "cap" is a steel washer and nut JB Welded to the aluminum tube. It is extremely secure. The booster is also extremely robust, everything being reinforced short of glassing. The impacting nose cones are balsa with a coat of CA, so they are a bit "soft". The booster pod is meant to look like an unstable cluster rocket, hence the "Naughty Little Davy" stuff. For full effect it has to be a staged, heads up launch, only in front of Top Men at a secret launch site. The planned launch lingo will be quite unique if allowed.

    I will get some more photos as it is in paint now.
     
  12. May 31, 2017 #12

    MCriscione

    MCriscione

    MCriscione

    Well-Known Member

    Joined:
    Jul 9, 2015
    Messages:
    295
    Likes Received:
    0
    Sounds like you've thought it through. I figured as much. :cyclops:

    I'm looking forward to paint on this one. Lots of opportunity for detail.
     
  13. May 31, 2017 #13

    Daddyisabar

    Daddyisabar

    Daddyisabar

    Well-Known Member

    Joined:
    Jan 23, 2009
    Messages:
    4,285
    Likes Received:
    55
    Gender:
    Male
    Location:
    Littleton Colorado
    Only as far as mindsim can take me! Going to do a Pershing 1A like scheme on the booster pod. All kinds of applications for this type of rocket from Slide Rules to oil rig towers to Wonkavators.
    View attachment Tractor Motor concepts.pdf
     
  14. Jun 1, 2017 #14

    Scotty Dog

    Scotty Dog

    Scotty Dog

    Well-Known Member

    Joined:
    Mar 2, 2010
    Messages:
    7,300
    Likes Received:
    88
    That's different for sure..just remember..and I know you thought it all thru...but I still I have to say this..."Safety First"

    Thanks for entering the MODSBO Contest.
     
  15. Jun 1, 2017 #15

    Daddyisabar

    Daddyisabar

    Daddyisabar

    Well-Known Member

    Joined:
    Jan 23, 2009
    Messages:
    4,285
    Likes Received:
    55
    Gender:
    Male
    Location:
    Littleton Colorado
    More photos:

    LP 21.jpg
    Tubes secure!

    Lp 22.jpg
    Purdy Pershing Paint. Real easy, no pain, just stick on letters and tape.

    LP 20.jpg
    Put on a set of four new shockers.

    Lp 23.jpg
    Tip painted.
     
  16. Jun 1, 2017 #16

    rstaff3

    rstaff3

    rstaff3

    Oddroc-eteer

    Joined:
    Jan 18, 2009
    Messages:
    11,716
    Likes Received:
    7
    Lookin' good.
     
  17. Jun 1, 2017 #17

    Daddyisabar

    Daddyisabar

    Daddyisabar

    Well-Known Member

    Joined:
    Jan 23, 2009
    Messages:
    4,285
    Likes Received:
    55
    Gender:
    Male
    Location:
    Littleton Colorado
    Thanks. Maybe you could build something too!:) Possible ideas: Cant the motors on basically the same platform and pull up branches to make a tractor motored Christmas Tree rocket? Haul up some telescoping ring fins to make a layer cake design for the wife's birthday. Haul up a flag or banner (canted motors.) Tape some Barbie dolls on to the mount - JET PACK BARBIES! Make an atom smasher or an interior profile of Little Boy where the "gun" method worked the first time with out testing! An erupting volcano with a big cone fin - canted motors - pyroclastic flow! Life at conception - where the sperm crashes up into the egg, sure to get bonus points from both your Priest and Biology Teacher! Pop the Zit - OK, now I am getting into trouble, but it could work if you think about it!
     
  18. Jun 5, 2017 #18

    Daddyisabar

    Daddyisabar

    Daddyisabar

    Well-Known Member

    Joined:
    Jan 23, 2009
    Messages:
    4,285
    Likes Received:
    55
    Gender:
    Male
    Location:
    Littleton Colorado
    More build picts:

    LP FIn 4.jpg

    LP Fin 6.jpg

    LP FIn3.jpg

    LP Fin 5.jpg

    LP FIn2.jpg
     

    Attached Files:

  19. Jun 5, 2017 #19

    rstaff3

    rstaff3

    rstaff3

    Oddroc-eteer

    Joined:
    Jan 18, 2009
    Messages:
    11,716
    Likes Received:
    7
    Looking good!
     
  20. Jun 6, 2017 #20

    Daddyisabar

    Daddyisabar

    Daddyisabar

    Well-Known Member

    Joined:
    Jan 23, 2009
    Messages:
    4,285
    Likes Received:
    55
    Gender:
    Male
    Location:
    Littleton Colorado
    !

    Thanks! Hope to fly at the June Tripoli launch.
     
  21. Jun 16, 2017 #21

    Daddyisabar

    Daddyisabar

    Daddyisabar

    Well-Known Member

    Joined:
    Jan 23, 2009
    Messages:
    4,285
    Likes Received:
    55
    Gender:
    Male
    Location:
    Littleton Colorado
    Looks like a burn ban in Park County. :( No joy.
     
  22. Jun 16, 2017 #22

    rstaff3

    rstaff3

    rstaff3

    Oddroc-eteer

    Joined:
    Jan 18, 2009
    Messages:
    11,716
    Likes Received:
    7
    Aw shucks, that stinks.
     
  23. Jun 16, 2017 #23

    Daddyisabar

    Daddyisabar

    Daddyisabar

    Well-Known Member

    Joined:
    Jan 23, 2009
    Messages:
    4,285
    Likes Received:
    55
    Gender:
    Male
    Location:
    Littleton Colorado
    Maybe it can fly at the local club tomorrow, but that is also dependent on a number of factors. If all else fails it might take a trip to Estesland and Chili-Blaster.
     
  24. Jul 18, 2017 #24

    Daddyisabar

    Daddyisabar

    Daddyisabar

    Well-Known Member

    Joined:
    Jan 23, 2009
    Messages:
    4,285
    Likes Received:
    55
    Gender:
    Male
    Location:
    Littleton Colorado
    Estesland it was. After review by Top Men I once again found myself enjoying the quiet solace of the away pad while hooking up the four Mighty D motors with the spider like clip whip.

    Photos on pad:
    DLP 2.jpg DLP 3.jpg DLP 18.jpg

    Photos of flight:
    DLP 4.jpg DLP 5.jpg DLP 6.jpg DLP 7.jpg DLP 1.jpg

    All motors lit, flew up nice and straight like any good tractor motored rocket will. Then POP POP POP POP, little bits flew off. One chute of four deployed. One chute ripped off. One chute burned the shroud lines off. One chute just never caught enough air to deploy.


    Thanks to Deanna Mann for the flight photos!
     
  25. Jul 18, 2017 #25

    Daddyisabar

    Daddyisabar

    Daddyisabar

    Well-Known Member

    Joined:
    Jan 23, 2009
    Messages:
    4,285
    Likes Received:
    55
    Gender:
    Male
    Location:
    Littleton Colorado
    Post flight pictures and repairs. Two of the motors blew out the back. One hit directly on the fin knocking out a chuck of balsa. Flame action peeled back the label paper. Dents in the nose cones show the power of impact and ejection. Never underestimate the POWER of the MIGHTY D motor! Got a kink in the launch lug on landing with only 1.25 chutes. Jammed the 3/8" launch rod through and pounded out the damage. It will hang up a bit now on the 3/8" rod, so will have to go with a 1/4" rod for the next launch. So much for metal parts! Glued in a piece of scrap balsa on the fin. Super glued the paper back on. Cleaned up the soot. Gave it a quick Sharpie pen touch up paint job and ready to go again when I can get some more Q2G2s.

    DLP 10.jpg

    DLP 11.jpg

    DLP 12.jpg

    DLP 13.jpg

    DLP 14.jpg

    DLP 15.jpg

    DLP 16.jpg

    DLP 17.jpg
     
  26. Jul 18, 2017 #26

    rstaff3

    rstaff3

    rstaff3

    Oddroc-eteer

    Joined:
    Jan 18, 2009
    Messages:
    11,716
    Likes Received:
    7
    Woohoo! A stable flight and an opportunity to rebuild. Sounds 100% successful to me!
     
  27. Jul 18, 2017 #27

    Daddyisabar

    Daddyisabar

    Daddyisabar

    Well-Known Member

    Joined:
    Jan 23, 2009
    Messages:
    4,285
    Likes Received:
    55
    Gender:
    Male
    Location:
    Littleton Colorado
    Thanks! I love the oddroc flight standards! Coming off the rod it was the most stable rocket launched that day. Repairs were quick and easy.
     
  28. Jul 19, 2017 #28

    neil_w

    neil_w

    neil_w

    When in doubt, add more rocket TRF Supporter

    Joined:
    Jul 14, 2015
    Messages:
    6,493
    Likes Received:
    918
    Location:
    Northern NJ
    I have to say this thing is wacko even by oddroc standards. I love it. :)

    Get any video? I'd love to see the initial stage of the four-motor pod thing charging up the rod and hitting the stop at the end.
     
  29. Jul 19, 2017 #29

    TangoJuliet

    TangoJuliet

    TangoJuliet

    Well-Known Member

    Joined:
    Jun 26, 2016
    Messages:
    1,232
    Likes Received:
    3
    The damage isn't even as bad as I would have expected considering you only had one good chute and a nose down trajectory. And I'm with Neil, I want to see video!
     
  30. Jul 19, 2017 #30

    Daddyisabar

    Daddyisabar

    Daddyisabar

    Well-Known Member

    Joined:
    Jan 23, 2009
    Messages:
    4,285
    Likes Received:
    55
    Gender:
    Male
    Location:
    Littleton Colorado
    Thanks. Could not get the Fancy Phone to work at the last second before the launch, so no video and I actually got to watch it. In reality it is so fast it looks like a smooth launch of the power pod rockets. The noise and smoke of the motors lift the back end of the pad right off the rod, straight, fast and stable. Deanna did catch the moment of impact in her first launch photo above.

    Three canted motors on a tripod pad would work well. Less burn and not a substantial decrease in performance.

    The whole sliding motor thing is kind of silly and wacko. Maybe a next step would be to make an electrical connection and set off a light or sound effect.
     

Share This Page