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  1. #31
    Join Date
    21st January 2009
    Location
    HotRod Northern Command ....of Chaos.
    Posts
    159
    Wet pants, and the barefoot bandit... that's me.

    It wasn't the wind as much as the main chute and the upper section coming out about 500ft too early (drag or shake-loose separation).

    Name tags are not a bad idea. I seem to remember that in the not so distant past.

    See ya, and the wife next time.

    .

    David S. Mackiernan


    .........Chief Curmudgeon and agent of CHAOS

    http://hotrodrockets.weebly.com/

  2. #32
    Join Date
    18th January 2009
    Location
    Haverhill, MA
    Posts
    1,333
    Here's a couple of my videos from the launch.
    This one features the voice of CMASS Kenn Blade.

    http://www.youtube.com/watch?v=HRlqBj-IBt8


    http://www.youtube.com/watch?v=g6nF36Xhbw4

    And some screen caps.

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    Tony Vincent
    NAR 45082 L1
    Member CMASS & MMMSC

  3. #33
    Join Date
    28th July 2009
    Location
    Canton, MA
    Posts
    930
    The weather was great. Unfortunately, I didn't have a great landing of my Black Brant II. My three other flights were perfect. The I-ROC was once again a favorite of the children walking by. Now that the test flight has been done, it is now time to get working on getting it back to dual deployment once again.

    Jim, the Shadowlord is a great kit. You weren't kidding when you said it would be a mover. I look forward to flying it again in October.
    Peter Waithe
    NAR 86455
    Level 1: 1/21/07
    Level 2: 9/13/08
    Level 3: 6/25/11


  4. #34
    Join Date
    21st January 2009
    Location
    Massachusetts
    Posts
    1,015
    Thanks to Jim Flis of FlisKits for a fun day for everyone and for sponsoring the flight of the 9ft upscale Tres. Thanks to Carl Tulanko for building this beautifully crafted rocket and giving Jim and I permission to fly it. Thanks also to Doug Gardei for helping with motor retention and the loan of a case, Robert DeHate of AMW for the loan of another case and selling the motors, and to the many other helpful folks at CMASS.

    Pictures: Tres on display at FlisKits, on the way to RSO, prepping at the pad with lots of help.

    It took some creativity to temporarily convert a two-stage rocket with single-deploy first-stage recovery to a single-stage rocket with dual-deploy recovery.

    The upper section of the rocket (designed to be the second stage) fired the 3ft drogue at apogee out of its motor tube. Wires to switch on the altimeter can be seen taped to the outside of the rocket in the second picture.

    A second altimeter was inside a white 29mm pod I built for this flight, which can be seen in pictures 2 and 3. This connected to an ejection charge
    inside the lower section of the rocket (designed to be the first stage). A 7ft main brought the rocket down gently.

    A tiny BoosterVision DVR was taped to near the top of the rocket. Both the white altimeter pod and DVR were removed cleanly after the flight.
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    Last edited by delta22; 26th September 2010 at 10:26 PM.
    Boris Katan
    NAR / TRA L3
    Lots of fun cluster rocket pictures and video at: www.bpasa.com

  5. #35
    Join Date
    21st January 2009
    Location
    Massachusetts
    Posts
    1,015
    Used two igniters in each of the 3x AMW/CTI 38mm 3grain I-212 Smokey Sam motors, one Rocketflite ML and one ematch that came with each motor.

    The huge Tres kicked off the pad quickly and cleanly rising on a column of dense black smoke. The visual effect of the three smoke trails was very cool.

    Liftoff weight was close to 18 lbs and went up on a J cluster with about 1100 Ns of impulse and 600 N of thrust. The 2 Perfectflite HA45K altimeters reported 1440 and 1452 feet.

    Flight video here includes both onboard and from the ground:

    Standard Def (9MB) http://www.bpasa.com/Movies2010/Tres4a.wmv

    High Def (26MB) http://www.bpasa.com/Movies2010/Tres4a.mpg

    Jim Flis can be heard expressing his delight with the flight in the video.

    It took me a week to get this posted because my computer kept crashing while trying to edit content from two new video cameras. After flashing the PC's BIOS, updating video, sound, chipset and network drivers, and removing a sound card and second monitor, I was able to run the combination of editing programs that got the results I was looking for.
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    Last edited by delta22; 26th September 2010 at 03:52 AM.
    Boris Katan
    NAR / TRA L3
    Lots of fun cluster rocket pictures and video at: www.bpasa.com

  6. #36
    Join Date
    21st January 2009
    Location
    Massachusetts
    Posts
    1,015
    Both drogue and main deployed fully and on-time. The main was set to deploy at 700 ft which worked out well. The Tres came down gently in an open field of soft grass well away from spectators.

    The nose cone did not play a role in this recovery, so I tethered it and left it loose fitting so it would separate during recovery and not be driven into the ground by the weight of the rocket body. There was some tangling between the long drogue and main harnesses, but the chutes were unaffected by this.

    While all aspects of doing this flight were a lot of fun, I particularly enjoyed the clean recovery as I was flying a finely-crafted rocket that belonged to someone else.

    Jim and I were feeling pretty good after the flight.
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    Last edited by delta22; 26th September 2010 at 04:10 AM.
    Boris Katan
    NAR / TRA L3
    Lots of fun cluster rocket pictures and video at: www.bpasa.com

  7. #37
    Join Date
    18th January 2009
    Location
    Haverhill, MA
    Posts
    1,333
    Great video Boris.
    Your launches are always the high light of any CMASS launch.

    If Jim's voice was a little higher he would have sounded like a giddy school girl.
    Tony Vincent
    NAR 45082 L1
    Member CMASS & MMMSC

  8. #38
    Join Date
    18th January 2009
    Location
    Merrimack, NH
    Posts
    15,342
    Yeah, I was feeling pretty good about that flight

    Great shots Boris and I love the video!

  9. #39
    Join Date
    28th January 2009
    Location
    Cincinnati, Ohio
    Posts
    18
    Jim,

    Congratulations on your anniversary of Flistkits and you know I wish you and Kathy all the best you deserve. It looks like you had a great crowd and that's what makes it an even better event. You have come a long way bro!

    Boris, thank you for taking good care of one of my kids, the Tres, and great job on the launch. I loved the video, which was very well done and I now want to get my hands on some full res pics...we will have to talk to Jim about that. Also, great job on the conversion...had I known you were going to put an Altimeter in the lower section, that much I could have sent, as I have a bolt in bay for it built and hanging on my workbench. You managed to work around that though and did a great job prepping and flying her and I was glad to see it got in the air again. She came off the pad like normal, nice and brisk but not too fast, just as I remembered. I don't think Jim stopped giggling until it was back at the tent!!! Thanks again for all your efforts!

    Also, thanks to all of those that pitched in and helped make Jim and Kathy's day a memorable one.

    Best wishes,

    Carl
    Last edited by CTulanko; 27th September 2010 at 06:40 AM.
    Carl Tulanko
    NAR L3CC Member
    AMA 218214
    N8DWN

  10. #40
    Join Date
    18th January 2009
    Location
    Merrimack, NH
    Posts
    15,342
    Quote Originally Posted by CTulanko View Post
    Jim,

    Congratulations on your anniversary of Flistkits and you know I wish you and Kathy all the best you deserve. It looks like you had a great crowd and that's what makes it an even better event. You have come a long way bro!

    Boris, thank you for taking good care of one of my kids, the Tres, and great job on the launch. I loved the video, which was very well done and I now want to get my hands on some full res pics...we will have to talk to Jim about that. Also, great job on the conversion...had I known you were going to put an Altimeter in the lower section, that much I could have sent, as I have a bolt in bay for it built and hanging on my workbench. You managed to work around that though and did a great job prepping and flying her and I was glad to see it got in the air again. She came off the pad like normal, nice and brisk but not too fast, just as I remembered. I don't think Jim stopped giggling until it was back at the tent!!! Thanks again for all your efforts!

    Also, thanks to all of those that pitched in and helped make Jim and Kathy's day a memorable one.

    Best wishes,

    Carl
    I was thinkin' 'bout ya, bro. All month long It was great to see her in the air again and the folks at CMASS really enjoyed it. Her older sister, the 38mm Deuce, is on display at a local hobby shop so neither is sitting in a dark corner collecting dust

  11. #41
    Join Date
    20th August 2010
    Posts
    292
    Quote Originally Posted by delta22 View Post
    It took me a week to get this posted because my computer kept crashing while trying to edit content from two new video cameras. After flashing the PC's BIOS, updating video, sound, chipset and network drivers, and removing a sound card and second monitor, I was able to run the combination of editing programs that got the results I was looking for.
    Then you definitely don't want to hear that these videos will not play on my mac with the both the Perian and Flip4Mac codec packages installed which cover all but the most bizarre video formats. ;-) Fortunately I *can* play them with VLC, which is a good thing, because both the videos and the flight kick serious ass! And that laugh... Yeah, I know that laugh. ;-)

  12. #42
    Join Date
    20th August 2010
    Posts
    292
    I'm not really sure where to ask this, so I figured I'd just ask here....

    One of the things I noticed about this flight, in both the ground and on-board cameras, was the very distinct exhaust plumes. I can't ever recall seeing such pronounced plumes in a cluster launch before. The reason became very clear when I saw the photo of you guys prepping the model on the pad.

    I am aware of the practice in clusters of canting motors towards the center to keep the model going straight if one or more motors fail to ignite. What I am not sure of is how to calculate that angle. I am guessing that it is not calculated, per se, but rather one experiments with various angles in a simulator until a straight flight is achieved with a single motor. Is there a tutorial somewhere that shows how to do this?

    Nonetheless, my gut tells me that these motors might be canted to an even greater degree, perhaps specifically to achieve the great visual effect. any comments on this as well?

  13. #43
    Join Date
    21st January 2009
    Location
    Massachusetts
    Posts
    1,015
    This is an upscale of an existing kit, the FlisKits Tres, which has these canted motors specifically to create this very cool triple motor plume.

    Jim Flis showed a beautiful 24mm Tres (currently available kit is 18mm) at the last CMASS launch and I requested to order one as soon as they become available.

    If designing a cluster rocket from scratch, canting the motors towards the center of mass is a very sound design concept. If one or more motors is not ignited at launch, then the others will still be pushing the center of mass of the rocket in an upwards trajectory.

    I saw an upscale Deuce (another cool FilsKits kit) fire only one of its two motors at LDRS28 and still achieve a safe and very cool flight because of its canted motors and big fins.

    Jim flew the 24mm Tres prototype and one of the three motor tubes stripped off the rocket and it still had a great flight!

    The Tres also benefits from having length and a lot of distributed fin surface, so it wants to be a very stable rocket.

    For this flight I used dual igniters in each motor, one CTI and one Rocketflite, mostly to assure getting the full impulse of the three motors. If only two canted I-212 motors had fired, the 18 lb rocket would have accelerated at about 5Gs and struggled with slow speed and low deployment.
    Boris Katan
    NAR / TRA L3
    Lots of fun cluster rocket pictures and video at: www.bpasa.com

  14. #44
    Join Date
    19th January 2009
    Location
    Tucson, Az
    Posts
    2,350
    According to Apogee the optimum angle for canted motors is one that passes thru a point midway between the center of pressure and the center of gravity. This can be tricky to do on a high power design where the motors and components can vary. The choice of engines is another variable, lower thrust motors give a smoother performance if all light but a marginal performance if some do not light. Higher thrust motors give better thrust to weight ratios with partial ignition but subject the rocket to much higher forces if ignition is not perfectly timed. Some way to be able to adjust the engine cant angle on the fly would be ideal but I am not sure how it could be designed.
    more rockets then cents

  15. #45
    Join Date
    20th August 2010
    Posts
    292
    Thanks Terry, that was exactly the bit of information I was looking for. If this came from Apogee, that almost certainly means that there is a tech bulletin on the topic which will have some more great tips, including how to design in RockSim.

    I can imagine several different ways to obtain the ability to change the cant angle. The most straightforward would be a removable cluster motor mount, where the cant angle in each individual mount would be fixed.

    Infinitely variable cant angles are a bit more tricky, but I already have an idea as to how I might do it. I make all of my own motors and casings, so it would be easy enough to fashion a forward bulkhead with a through-pin fitting. This would be both the pivot point as well as the thrust "ring". No clear ideas as yet how to best lock down the nozzle end to the desired angle, but I am sure I will come up with something.


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