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  1. #1
    Join Date
    18th June 2014
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    127

    2.6" Competitor 2 Stage - Configuration

    I just finished up my 2.6 Competitor 2 stage built. I'd like a bit of a sanity check to make sure I don't make any stupid mistakes, this is my first 2-stage HPR.

    Here is the Openrocket file : Red Tenacity - 2 stage.ork

    I plan to fly it with DMS H550 (0.6s burn time) in booster and a Loki H160-LB (w/pyrodex pellet) in the sustainer. Setup is as follows.

    Booster
    Eggtimer Quantum #1 (Drogue Channel) - separation charge at 0.7s,
    Eggtimer Quantum #1 (Main Channel) - chute deploy at apogee
    motor backup @ 7s

    Sustainer
    - Sustainer ignitor will be handled by Quantum #2 in middle ebay via conduit through MMT centering rings into bottom of motor as per normal launch, wire will be twisted and taped to allow break during drogue deploy
    Eggtimer Quantum #2 (Drogue Channel), airstart @ 1s after launch, altitude minimum (none), velocity minimum 100ft/s
    Eggtimer Quantum #2 (Main Channel), drogue deploy @ apogee
    Eggtimer TRS (Drogue Channel), drogue deploy @ apogee + 1s
    Eggtimer TRS (Main Channel), deploy @ 500ft

    My sim shows sustainer ignition @ 1s will be at height 156 ft, velocity 216 ft/s.

    For pad setup, I'll bring it up to the pad with both ignitors out
    - load the booster on the rail, arm the Quantum #1 via wifi and insert motor ignitor
    - load the sustainer on the booster (ignitor out)
    - arm eggtimer TRS
    - insert ignitor in sustainer
    - back off, ensure area is clear and arm Quantum #2

    Screenshots of the SIM & OR screen showing weights/motor selection.

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    Thanks for any help/advice you can offer.

    cheers - mark


  2. #2
    Join Date
    22nd August 2015
    Location
    Rhode Island
    Posts
    1,284
    Lots of us are trying to use Eggtimer Quantum’s for staging. Please tell us how it works out.

    I don’t have the the manual in front of me right now, but I’m wondering if you can set the minimum altitude to 100 ft. I think the minimum value in the software is 300 ft. (I hope I’m wrong about that.)

    NAR #100940, RIMRA & CMASS
    L1 - 4/17/16, Tyrannosaur (by Binder Design), Loki H144
    L2 - 8/19/17, Terrordactyl (by Binder Design), CTI J250

  3. #3
    Join Date
    18th June 2014
    Posts
    127
    Quote Originally Posted by BDB View Post
    Lots of us are trying to use Eggtimer Quantum’s for staging. Please tell us how it works out.
    I don’t have the the manual in front of me right now, but I’m wondering if you can set the minimum altitude to 100 ft. I think the minimum value in the software is 300 ft. (I hope I’m wrong about that.)
    You are correct, I misread the manual. 300ft min, and min speed is 100ft/s change by 100ft/s. I'll edit my first post to reflect these changes.

  4. #4
    Join Date
    22nd August 2015
    Location
    Rhode Island
    Posts
    1,284
    But that creates the problem. According to your simulation plot, you won't be over 300 ft when you want to light the sustainer. I'm having some of the same issues with my simulations and I know one other TRF member here is too. We have both had the sustainer not light because we didn't exceed the minimum altitude for the safety lockout. I want to make this work for MPR and low HPR, but it seems like it's a matter of go big or go home (or build a MD 2-stage rocket that will stage above 300 ft on a G or H motor).
    NAR #100940, RIMRA & CMASS
    L1 - 4/17/16, Tyrannosaur (by Binder Design), Loki H144
    L2 - 8/19/17, Terrordactyl (by Binder Design), CTI J250

  5. #5
    Join Date
    18th June 2014
    Posts
    127
    Quote Originally Posted by BDB View Post
    But that creates the problem. According to your simulation plot, you won't be over 300 ft when you want to light the sustainer. I'm having some of the same issues with my simulations and I know one other TRF member here is too. We have both had the sustainer not light because we didn't exceed the minimum altitude for the safety lockout. I want to make this work for MPR and low HPR, but it seems like it's a matter of go big or go home (or build a MD 2-stage rocket that will stage above 300 ft on a G or H motor).
    Yes, I'll set the altitude minimum to 'OFF' to avoid that problem. It'll still have the velocity check of 100ft/s as a safety. I'd have to bump to booster up to an i500T (380ft) or larger to be able to use the altitude minimum check.

  6. #6
    Join Date
    22nd August 2015
    Location
    Rhode Island
    Posts
    1,284
    Good point. This is one of the cases where it makes sense to only use velocity as the safety lockout.
    NAR #100940, RIMRA & CMASS
    L1 - 4/17/16, Tyrannosaur (by Binder Design), Loki H144
    L2 - 8/19/17, Terrordactyl (by Binder Design), CTI J250

  7. #7
    Join Date
    29th December 2013
    Location
    Bayport MN
    Posts
    167
    Be sure to check your launch detect altitude.

    Sent from my LG-V521 using Rocketry Forum mobile app
    L1 - Madcow 4" Phoenix I180 Skidmark 1651 feet
    L2 - Darkstar 2.6" J145 Skidmark longburn 4787 feet
    L3 - Terminator 5" M1297 White Lightning 8602 feet

    TRA 15743
    NAR 30949
    http://www.rocketreviews.com/karl-tyrrells-page.html

  8. #8
    Join Date
    18th June 2014
    Posts
    127
    Okay, I put the whole shebang together last night and here is the final setup for flight on Saturday :

    Booster
    - H550ST, delay 7 seconds
    - Quantum Drogue - nose over (1g) for parachute
    - Quantum Main - timer - 0.7s (5g) for separation charge

    Sustainer
    - Loki H160 w/pyrodex pellet, 12 second delay
    - TRS Main - 500 ft (1g)
    - TRS Drogue - Nose-over + 1s (1g)
    - Quantum Drogue - Nose-over (1g), 2 sec pulse
    - Quantum Main - air start, timer 0.9s, min velocity 100ft/s, 2 sec pulse

    The main only has one charge as the Quantum can't do an altitude release when in airstart mode. I may drop a Quark in there in the future to have a redundant main. The drogue has 3 charges, so that should get out for sure.

    If that flight goes well, I'll fly it again on Sunday with an I500/H90Red.

    If it doesn't go well I'll delete this post and pretend it never happened

    cheers - mark

  9. #9
    Join Date
    18th January 2009
    Posts
    1,890
    Good luck on your project. I haven't studied it in any detail, but I have a couple of comments (if I'm off base, just delete and pretent it never happened).

    I think your general timing seems a bit quick. With a motor burn of 0.6 seconds and a separation charge at 0.7, it doesn't seem like it would take much for the two events to overlap. Why not allow a little coast and then also be able to use an altitude check? I'd separate at 1 second and light at 2.

    I'm not familiar with the quantum, but why would you use a 2 second pulse? If this is the altimeter latch time, I always try to use the shortest possible time in case the igniter shorts.

    I'd put in the booster igniter last.

    I would also recommend an all-up test of the electronics before loading the sustainer. With the igniter out and the rocket vertical, turn on all the electronics and make sure the igniter doesn't fire. Turn everything off, load the rocket and go. You want to do everything you can to ensure the sustainer won't fire on the pad, even if you back off before arming the Quantum.

    Jim

  10. #10
    Join Date
    18th June 2014
    Posts
    127
    Hi Jim,

    Thanks for your comments. I welcome your advice!

    Quote Originally Posted by JimJarvis50 View Post
    I think your general timing seems a bit quick. With a motor burn of 0.6 seconds and a separation charge at 0.7, it doesn't seem like it would take much for the two events to overlap. Why not allow a little coast and then also be able to use an altitude check? I'd separate at 1 second and light at 2.
    I reread the Quantum documentation and Cris suggests burn time + 20%, so 0.7 is a little quick. I'll bump it to 1 second. My sim shows velocity at 216ft/s at 1s, 196ft/s at 1.5 and 180ft/s at 2s. I thought it would be best to get the sustainer lit as soon as possible, that's why I set it at 0.9s. I'm also not sure how fast the sustainer will start and get up to pressure, so I figured sooner is better than later?

    If I change the sim to 1s separation and 2s ignition, it drops the altitude by about 100ft. I'm not going for altitude, so this doesn't bother me. I just want to make sure the rocket is pointing up when the sustainer lights!

    Okay, I ran the sim again. Even if I light at 3s, it is still going 142ft/s, which should still be fine. I'm going to change it to 1s separation, 2s ignition.

    Quote Originally Posted by JimJarvis50 View Post
    I'm not familiar with the quantum, but why would you use a 2 second pulse? If this is the altimeter latch time, I always try to use the shortest possible time in case the igniter shorts.
    2 seconds is the default on the Quantum. From the Quantum airstart manual, Cris gives the settings for his flight, he used a pulse time of 4 seconds. Also according to the Quantum manual, it should survive a short from the igniter. I have redundancy on the Drogue and the Main is handled by another computer, so even if the Quantum craps out after sustainer ignition I should be okay.

    Quote Originally Posted by JimJarvis50 View Post
    I'd put in the booster igniter last.
    I would also recommend an all-up test of the electronics before loading the sustainer. With the igniter out and the rocket vertical, turn on all the electronics and make sure the igniter doesn't fire. Turn everything off, load the rocket and go. You want to do everything you can to ensure the sustainer won't fire on the pad, even if you back off before arming the Quantum.
    Sounds like a good plan, I'll alter my checklist to match.

    cheers - mark

  11. #11
    Join Date
    18th January 2009
    Posts
    1,890
    I'm not sure if you're pyrodex pellet is something you're adding or built into the motor, like CTI. If it's built in, ignition would be fast. If you're adding it, then who knows. Pyrodex pellets burn pretty fast. I don't use them any more, but when I did, I would fill the center hole with epoxy to slow down the burn a little. Now, I use dipped ematches using the PML magnelite. It works quite well.

    I see the 1-9 seconds for the firing time. Not sure why that is (maybe Cris can explain the philosophy of that), but I guess it doesn't hurt anything. Just for reference, I typically use 0.1 seconds for ematches.

    Jim

  12. #12
    Join Date
    18th June 2014
    Posts
    127
    Success!

    First flight was an Aerotech H550ST -> Loki H160 Blue

    Booster separation charge was set for 1s, sustainer ignition was set for 2s.

    Looking at the video and the data, I'm wondering if it's possible that the separation charge (0.5g) lit the motor? I don't see any slowdown of the sustainer at all, just a steady increase in speed, which matches what I see on the video. I should have increased the samples per second on the Quantum, I had it at the default 20/s. If it wasn't the separation charge, then the igniter/pyrodex just lit the motor really quickly.

    In any case, the first flight was a success, apogee 3392ft which is as close as I will ever get to a simulated altitude (3387ft). Both booster and sustainer were easily recovered with no damage. I did lose sight of the sustainer due to the cloud cover but saw it on descent and the TRS tracker had signal as well. Sustainer landed about 1000 ft away from the pad, the booster was reasonably close as well. Booster apogee was 500ft.

    (I wish youtube had a vertical video format)



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  13. #13
    Join Date
    18th January 2009
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    Quote Originally Posted by markg View Post
    Success!

    First flight was an Aerotech H550ST -> Loki H160 Blue

    Booster separation charge was set for 1s, sustainer ignition was set for 2s.

    Looking at the video and the data, I'm wondering if it's possible that the separation charge (0.5g) lit the motor?
    Looks like it lit around 1.5 seconds? Maybe the separation charge lit the pellet? Can't say I would have expected that, but maybe it's not that surprising. I always cover the nozzle of the sustainer motor in some way. With larger motors, it's a cap over the nozzle. With CTI motors, I just use the red nozzle cap. Good flight though.

    Jim

  14. #14
    Join Date
    21st January 2009
    Location
    Manitowoc, WI
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    Quote Originally Posted by markg View Post
    Success!

    First flight was an Aerotech H550ST -> Loki H160 Blue

    Booster separation charge was set for 1s, sustainer ignition was set for 2s.

    Looking at the video and the data, I'm wondering if it's possible that the separation charge (0.5g) lit the motor? I don't see any slowdown of the sustainer at all, just a steady increase in speed, which matches what I see on the video. I should have increased the samples per second on the Quantum, I had it at the default 20/s. If it wasn't the separation charge, then the igniter/pyrodex just lit the motor really quickly.

    In any case, the first flight was a success, apogee 3392ft which is as close as I will ever get to a simulated altitude (3387ft). Both booster and sustainer were easily recovered with no damage. I did lose sight of the sustainer due to the cloud cover but saw it on descent and the TRS tracker had signal as well. Sustainer landed about 1000 ft away from the pad, the booster was reasonably close as well. Booster apogee was 500ft.

    (I wish youtube had a vertical video format)



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    Great flight, Mark! Well done, and I was especially impressed with your use of a thorough checklist out at the pads! Congrats on the great flight!
    Eric Cayemberg
    TRA 7783 L3
    TAP

  15. #15
    Join Date
    3rd February 2012
    Location
    So Cal (ROC, TRASD, SCRA)
    Posts
    2,662
    Nice flight! To me, it looks like the separation happened about 1/2 second before the sustainer lit... look at 0:03 to 0:04, it looks like the booster separated before the sustainer starts to take off on its own.

  16. #16
    Join Date
    18th June 2014
    Posts
    127
    The second flight didn't go as well.

    It was an Aerotech I500ST -> Loki H90Red.

    Separation charge @ 1.8s, sustainer ignition @ 2.8s.

    From the video and pictures, it looks like it did not separate at 2.8s but held together until the sustainer motor started. It was also weather cocking, so when the sustainer lit it was more horizontal than vertical.

    From the pictures it looks like the sustainer finally got lit 8-10 seconds into the flight. It lit just before the booster hit apogee, the pictures my wife took show the booster kicking out it's chute through motor ejection, followed by the backup apogee charge from the quantum - and the sustainer lit and flying away.

    I'd already lost sight of the sustainer at that point, and she switched to follow the booster, so I'm not really sure what happened with the sustainer. The booster had an apogee of 2200ft, and fired it's noseover charge at 11.8 seconds.

    The sustainer (which probably lit around 2000ft) had an apogee of 2540 and fired it's noseover charge at 13.9 seconds. The sustainer did get it's main out and I saw it land, in about the same spot as the first flight, about 1000 ft from the pad.

    The sustainer landed in about the same spot as it's first flight. The drogue chute had a couple of shrouds pulled out, so I'm wondering if it came out when the rocket was moving horizontally or even downwards at a high rate of speed. I didn't download the TRS data yet, but the Quantum data shows apogee at 12.9 seconds, then noseover & drogue fired at 13.9. From 13.25->13.9 the speed goes from -27.64 -> -200.26.

    I think I'm going to repeat both flights before I try something new. Before I fly again :

    - test lighting the Loki H160/H90 on the ground with the igniter & pyrodex pellet to see how quickly it lights and see if I have to make a change with the igniter
    - test the 0.5g separation charge
    - cover the bottom of sustainer motor with masking tape to prevent possible lighting of the sustainer by the separation charge (there's no cap or nozzle cover on Loki 38s)
    - increase the samples / second on the Quantums to get more data

    Here's the photo of the sustainer going and the booster firing it's backup ejection charge :

    Click image for larger version. 

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  17. #17
    Join Date
    18th June 2014
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    127
    Quote Originally Posted by ECayemberg View Post
    Great flight, Mark! Well done, and I was especially impressed with your use of a thorough checklist out at the pads! Congrats on the great flight!
    Thanks Eric, you had a bunch of great flights between yourself and the rest of your clan!

    cheers - mark

  18. #18
    Join Date
    13th June 2014
    Location
    Cocoa Beach, FL
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    3,711
    The problem with most red motors is they are prone to chuffing. Iíve encountered it on all my Loki reds and have observed same with AT reds. Really not the best choice for 2nd stage motors.
    Tim
    L3 NAR 98225

  19. #19
    Join Date
    18th June 2014
    Posts
    127
    Quote Originally Posted by cerving View Post
    Nice flight! To me, it looks like the separation happened about 1/2 second before the sustainer lit... look at 0:03 to 0:04, it looks like the booster separated before the sustainer starts to take off on its own.
    Okay, I went back and checked the original video. There are about 13 or 14 frames between when the separation occurs and the sustainer first shows some smoke. At 30fps, that's 0.5 seconds. It should have coasted for one second.

    I pulled the original video into a video editor. Here's what I see :

    (2 seconds, 9 frames)
    2:09 rocket starts moving
    (3 seconds, 17 frames)
    3:17 rocket separates (I can hear the separation charge fire shortly after I see it)
    (3 seconds, 30 frames)
    3:30 sustainer lights

    So it seems like either the Sustainer Quantum lit the sustainer motor a little early or the sustainer moter was lit by the separation charge and just took a bit of time to get going.

    It seems like the two Quantums were out of sync with their samples, maybe it has something to do with that. For instance :

    Booster :
    T Alt Veloc FAlt FVeloc LDA
    0.45 91 40 67.28 118.58 0
    0.5 98 140 73.43 122.86 0
    0.55 107 180 80.14 134.29 107

    Sustainer:
    T Alt Veloc FAlt FVeloc LDA
    0.45 111 260 65.3 228.52 111
    0.5 122 220 76.64 226.82 0
    0.55 127 100 86.71 201.45 0

    cheers - mark

  20. #20
    Join Date
    3rd February 2012
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    So Cal (ROC, TRASD, SCRA)
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    Yeah, taking 5 seconds to light is not good for a sustainer. I like smokey motors for the sustainer because they light easily and you can see them really well, blues and whites are good too. It looks like your sustainer may have gotten stuck in the transition coupler somehow... I've had that happen, hopefully it didn't cook anything too bad when the motor lit.

    As far as the timing difference between the two Quantums, there will be some natural pressure variation and since they're in two different locations on the rocket (one right behind a set of fins...) it's entirely possible that they might not be totally "in sync". That's why I recommend at least a one second difference between separation and lighting the sustainer. You can crank that up an extra half second for a little more insurance.


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