Patriot Redux build thread

Discussion in 'High Power Rocketry (HPR)' started by JoeTekcor, Sep 10, 2019.

Help Support The Rocketry Forum by donating:

  1. Sep 10, 2019 #1

    JoeTekcor

    JoeTekcor

    JoeTekcor

    Forum Supporter TRF Supporter

    Joined:
    Sep 24, 2018
    Messages:
    83
    Likes Received:
    25
    Gender:
    Male
    IMG_7102.jpg
    So due to a mishap at LDRS where I looked at the wrong sheet to see how much to adjust the delay charge my 4” Madcow Patriot ejected too late. The result, a 6” zipper and a lost nose cone.
    Planning on rebuilding it and modifying it a little. Have a shopping cart ready on the Madcow site for a new nose cone (Long ogive this time), coupler and a 31” body tube.
    I’ve cut the zippered section off. I plan on adding the 31” section there and adding the new nose cone. It’ll definitely be longer than the original and the longer length means I don’t have to put quite as much weight in the nose cone. Built it in openrocket and it looks good.
    I’ll update the payload bay for altimeter deployment. I need a longer shock cord too.
    I’ll post pics once I get started.

    This was my level one rocket. Seems fitting to rebuild and possibly use it for my level 2.
     
  2. Sep 10, 2019 #2

    AfterBurners

    AfterBurners

    AfterBurners

    Forum Supporter TRF Supporter

    Joined:
    May 8, 2012
    Messages:
    6,909
    Likes Received:
    129
    Gender:
    Male
    Location:
    Dallas Texas
    I remember when I built my MADCOW Patriot I think I used 43oz of nose weight or something ridiculous. I used Rocksim for the sim. Anyway good luck on the rebuild.
     
    JoeTekcor likes this.
  3. Sep 10, 2019 #3

    Nytrunner

    Nytrunner

    Nytrunner

    Master of Rivets

    Joined:
    Oct 15, 2016
    Messages:
    5,475
    Likes Received:
    1,289
    Gender:
    Male
    Location:
    Huntsville AL
    Refit the payload bay for dual deploy! It's a good learning/growth opportunity as you move to L2.

    Used it for my L1 too (sig vv)! Before I knew anything about high-power, but it's a tough one that's eaten H-J so far. I'm building a 2nd payload bay for Dual deployment to stick on it also, so I can fly the J150 Mellow plugged long-burn in the Pro38 6Gr XL case
     
    JoeTekcor likes this.
  4. Sep 10, 2019 #4

    JoeTekcor

    JoeTekcor

    JoeTekcor

    Forum Supporter TRF Supporter

    Joined:
    Sep 24, 2018
    Messages:
    83
    Likes Received:
    25
    Gender:
    Male
    Same. I think that’s why my nose cone popped off. Broke the sheer pins and the elastic cord I had in place as a backup. It’s probably buried a couple feet deep in a Kansas pasture.
     
  5. Sep 10, 2019 #5

    JoeTekcor

    JoeTekcor

    JoeTekcor

    Forum Supporter TRF Supporter

    Joined:
    Sep 24, 2018
    Messages:
    83
    Likes Received:
    25
    Gender:
    Male
    That’s the plan. Plenty of room on the sled in the payload bay for the electronics.
     
    Nytrunner likes this.
  6. Sep 10, 2019 #6

    Nytrunner

    Nytrunner

    Nytrunner

    Master of Rivets

    Joined:
    Oct 15, 2016
    Messages:
    5,475
    Likes Received:
    1,289
    Gender:
    Male
    Location:
    Huntsville AL
    Good show. It does require a few oz of weight in the forward end, so might as well make the weight do something.
     
  7. Sep 17, 2019 #7

    JoeTekcor

    JoeTekcor

    JoeTekcor

    Forum Supporter TRF Supporter

    Joined:
    Sep 24, 2018
    Messages:
    83
    Likes Received:
    25
    Gender:
    Male
    Reading posts and watching YouTube rocket build videos while waiting on parts to arrive.
    My wish list has grown significantly.
     
  8. Sep 18, 2019 #8

    JoeTekcor

    JoeTekcor

    JoeTekcor

    Forum Supporter TRF Supporter

    Joined:
    Sep 24, 2018
    Messages:
    83
    Likes Received:
    25
    Gender:
    Male
    IMG_7139.jpg
    Parts arrived.
    Now when I spec’d this out in openrocket it showed stable, 1-1.5cal, depending on the motor. (after adding some weight back to the nosecone)
    Anything I should look for to verify that. I mean, I am lengthening the rocket quite a bit.
    Is the main body tube section ok being that long. I’m going to be setting this up for dual deploy. I could put the new section on top making the payload section more central but since I want to push CG up I figure having the payload bay higher would be better.
    Now that I’m looking at it I’m second guessing myself.
     
  9. Sep 18, 2019 #9

    JoeTekcor

    JoeTekcor

    JoeTekcor

    Forum Supporter TRF Supporter

    Joined:
    Sep 24, 2018
    Messages:
    83
    Likes Received:
    25
    Gender:
    Male
    Modified things.
    IMG_7141.jpg
    Electronics bay is in the middle now where marked in the photo.
    That leaves a 16” payload below for the drogue chute and 24” payload above for the main chute.
    Makes me feel better about the charges needed for deployment.
    I’ll put an adjustable weight system in the nosecone to alter stability depending on the motor used.
    Looks like I’ve got some work to do this weekend.
     
  10. Sep 18, 2019 #10

    Nytrunner

    Nytrunner

    Nytrunner

    Master of Rivets

    Joined:
    Oct 15, 2016
    Messages:
    5,475
    Likes Received:
    1,289
    Gender:
    Male
    Location:
    Huntsville AL
    I definitely didn't calculate how much longer you intended to make this!
     
  11. Sep 18, 2019 #11

    JoeTekcor

    JoeTekcor

    JoeTekcor

    Forum Supporter TRF Supporter

    Joined:
    Sep 24, 2018
    Messages:
    83
    Likes Received:
    25
    Gender:
    Male
    I figure what the hell
     
  12. Sep 19, 2019 #12

    ECayemberg

    ECayemberg

    ECayemberg

    Well-Known Member

    Joined:
    Jan 21, 2009
    Messages:
    2,573
    Likes Received:
    232
    Hi Joe,

    I used a 4" Patriot for my L1 and L2 as well! Something similar happened to me....I flew the stock (PML) Patriot for my L1 (January '00). Flew it again the same day and it got hung up in a tree. No damage from the flight, but getting it down from the tree damaged the top of the booster airframe...Wisconsin winter and unreinforced phenolic meant a brittle airframe. So I too lengthened it and used it later for my L2 flight...and 22 flights since then, before retiring it.

    One word of caution for your plans...where simulators and real world don't necessarily agree. The fins on the Madcow Pat have a very small span; they're fairly close to scale. Adding that ~31" tube onto your Patriot may theoretically improve stability in the simulation world. However, with the short span of the fins and the increased volume of airframe above the fins, it only takes a few degrees of angle of attack for the fins to be "blanked out" by the hole punched in the air by the airframe. I just wanted to give a heads up...the rocket may fly just fine; but I've seen similar rockets "search" for stability on ascent when the fin span is limited and rocket is "long". I've also seen them do loops. The solution is more span on the fins...but that's tough to do without building another booster.

    Good luck either way!!!:)
     
  13. Sep 19, 2019 #13

    JoeTekcor

    JoeTekcor

    JoeTekcor

    Forum Supporter TRF Supporter

    Joined:
    Sep 24, 2018
    Messages:
    83
    Likes Received:
    25
    Gender:
    Male
    The short fins do worry me. Unfortunately only one way to know for sure and by then it’s too late.
    I might go the cautious route and cut that 31” tube down in size.
    Regardless I’m building a modular nose cone weight system similar to the LOC setup. Lots of stability difference between and I and J motor.
     
  14. Sep 21, 2019 #14

    JoeTekcor

    JoeTekcor

    JoeTekcor

    Forum Supporter TRF Supporter

    Joined:
    Sep 24, 2018
    Messages:
    83
    Likes Received:
    25
    Gender:
    Male
    IMG_7149.jpg IMG_7150.jpg
    Lower body tube repaired.

    IMG_7148.jpg
    In the meantime I’m looking into the nose cone weight system. That’s an 8oz tube that can slide over a 1/4 rod put in the nose cone. Basically steel BB’s mixed with epoxy. I’m thinking about making 1” versions of this so I can add as much weight as needed depending on the motor.
     
    Nytrunner likes this.
  15. Sep 23, 2019 #15

    JoeTekcor

    JoeTekcor

    JoeTekcor

    Forum Supporter TRF Supporter

    Joined:
    Sep 24, 2018
    Messages:
    83
    Likes Received:
    25
    Gender:
    Male
    Finished reattaching the rail button and filling in all of the holes and seams on the lower half of the rocket.
    I cut 8” off of the upper body tube I bought. With the longer nose cone I will have added 24” to the total length of the rocket compared to the original design.
    Next I need to fill the upper spirals and sand and paint everything. Haven’t decided how I’m going to repaint yet.
    Next on the list:
    1) ordering new shock cords (one bad hawk recovery)
    2) making a new main parachute and drogue chute.
    3) buying electronics and hardware for dual deployment.
    Hoping to have it ready for the December launch to attempt my level 2.
     
  16. Dec 9, 2019 #16

    JoeTekcor

    JoeTekcor

    JoeTekcor

    Forum Supporter TRF Supporter

    Joined:
    Sep 24, 2018
    Messages:
    83
    Likes Received:
    25
    Gender:
    Male
    Completely forgot about this build thread. One week from launch. Decided to hold off on dual deployment other than using a chute release. Going to attempt my level 2 on it next week. Want to get that under my belt first and then I’ll get the altimeter deployment working.
    Here is the final paint job. Still have some internals to finish this week. Should be able to get it ready. IMG_7523.jpg
     
    neil_w likes this.
  17. Dec 10, 2019 #17

    Andrew_ASC

    Andrew_ASC

    Andrew_ASC

    UTC SEDS 2017 3rd/ SEDS 2018 1st

    Joined:
    Sep 22, 2017
    Messages:
    3,833
    Likes Received:
    492
    Gender:
    Male
    This advice was why I briefly lost my sanity and threw a Wildman Sandhawk in the trash after I decreased the fin span with a dremel to improve flutter characteristics for a K motor. Then pulled it out of trash and sold it as is on TRF. Heard at worst stories from Crazy Jim and E about how rockets have flopped like fish in away cell. Granted at least you aren’t making the fins narrower on a long rocket. Lol.
     
  18. Dec 18, 2019 #18

    Mrgbus

    Mrgbus

    Mrgbus

    Member

    Joined:
    Nov 13, 2019
    Messages:
    14
    Likes Received:
    2
    Gender:
    Male

Share This Page