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  1. #31
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    Forgot the pic...

    Reasonably new to rocketry and hailing from the land down under.. I speak metric... I know not of these feet and inches you speak of...

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  2. #32
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    Fin fillets came out ok'ish with 5min epoxy.

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    Need to figure out a better way to stop drips/runs/smears at the LE/TE boundaries.

    I'm looking forward to trying out the fixit epoxy clay with the next one - I'm hoping the longer working time and the ability to use isopropyl alcohol on a finger to smooth and shape will help, followed by CWF ad sanding...

    Reasonably new to rocketry and hailing from the land down under.. I speak metric... I know not of these feet and inches you speak of...

    QRS: #193
    AMRS: #148

    AMRS L1 (2018-03-18 - Mk4 Rocket Propelled Companion Pod)

  3. #33
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    Aaaaaaaannddd: white...
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    One day I'll have a spray booth that isn't just a wardrobe transport moving box in the back yard - accidental NC collision while painting with the inside of the box...
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    That's gonna need sanding and respraying - good thing it now gets to sit for a week to cure.
    Reasonably new to rocketry and hailing from the land down under.. I speak metric... I know not of these feet and inches you speak of...

    QRS: #193
    AMRS: #148

    AMRS L1 (2018-03-18 - Mk4 Rocket Propelled Companion Pod)

  4. #34
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    Almost forgot to glue the tea-bag shock cord mount in.. I built the tea-bag last night and left it to dry - I will have to remember to put that in before I go to bed tonight so it will be dry in time to fly when I get back...
    Reasonably new to rocketry and hailing from the land down under.. I speak metric... I know not of these feet and inches you speak of...

    QRS: #193
    AMRS: #148

    AMRS L1 (2018-03-18 - Mk4 Rocket Propelled Companion Pod)

  5. #35
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    Paste consistency epoxies make fin fillets so much easier and usually (I can still mess anything up sometimes) neater looking. I need to try the rocket formulated super thick epoxies like the epoxy clay or rocketpoxy. I had a ton of Rodbond left over from fishing rod building which is similar super thick consistency epoxy. It has served me well for many mid and low power applications.

  6. #36
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    Quote Originally Posted by snrkl View Post
    Fin fillets came out ok'ish with 5min epoxy.
    [...]
    I'm looking forward to trying out the fixit epoxy clay with the next one - I'm hoping the longer working time and the ability to use isopropyl alcohol on a finger to smooth and shape will help, followed by CWF ad sanding...
    Try longer curing epoxy the next time!

    It will not only level off on its own, but also give you time to go back an fix inevitable imperfections.
    Rocketpoxy also responds to alcohol the same was you described epoxy clay, but is FAR easier to work with. You can also add pigments to color the fillets to match either the body or the fins.
    I did one set of fillets with epoxy clay, and still had to go back and sand it in the end. Luckily, it sends relatively easily.


    So, how did it fly?

    a

  7. #37
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    HELP! 29mm NC mods - I've hit a problem solving wall!!

    update - much has happened.. Rocket is painted and awaiting it's waterslide name decal..

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    I am currently trying to figure out how to hack a nose cone to fit my freshly assembled and tested EFmini... I had the presence of mind to order 2 spares when I got the second aspire kit, so the hacking has begun..


    I have hacked the bottom off the NC:
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    I can get it all to fit if I insert the EFMini all the way to the nose and tilt it's arse up - a 2mm piece of poster board as a cheap sled, and the lipo under the sled..

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    My only issue is, how the hell to I close off the NC and put some kind of reliable retention on it?

    I have some spare 29mm tube (I have shortened the MACH version by 165mm) so my thought was to extend NC with some BT and use 3mm plastic rivets to secure the NC to the BT extension, then

    <???insert bulkhead and retention method???>

    is where I get stuck..

    I have plenty of 29mm couplers (in two thicknesses) and a half dozen 29mm COUPLER bulkhead disks (regular 29mm bulkhead disks would have been more useful, but I ordered these on a whim a month and a half ago...)

    Anyone tried modding a 29mm plastic NC for electronics before? Anyone have any ideas?
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    Reasonably new to rocketry and hailing from the land down under.. I speak metric... I know not of these feet and inches you speak of...

    QRS: #193
    AMRS: #148

    AMRS L1 (2018-03-18 - Mk4 Rocket Propelled Companion Pod)

  8. #38
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    A supersonic Apogee Aspire...

    Quote Originally Posted by afadeev View Post

    So, how did it fly?

    a
    Launch on the 14th was scrubbed due to TERRIBLE weather - new date is this weekend... I am really trying to get the EFMini into it so I can test it this weekend in preparation for the G80 MACH version on the Nov launch.. Nov will be my last launch for the year as my partner's work christmas party conflicts with the December launch...
    Last edited by snrkl; 26th October 2017 at 12:24 PM.
    Reasonably new to rocketry and hailing from the land down under.. I speak metric... I know not of these feet and inches you speak of...

    QRS: #193
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    AMRS L1 (2018-03-18 - Mk4 Rocket Propelled Companion Pod)

  9. #39
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    A supersonic Apogee Aspire...

    As typically happens - after spending 2 hours in frustrating contemplation without resolution, I posted and put it down for the night.

    30mins after I finished my last evening work calls, it hit me:

    I remembered that the magnesium supplement effervescent tablets I take - the container is a perfect fit for the ID of a 29mm tube - I even used one as a painting stand for this rocket.

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    Some cutting / sawing / drilling later:

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    Iíve epoxied the NC into the BT and Iím using 3 plastic push rivets to attach the shoulder

    Two small holes in the bottom of the vitamin tube will have a shock cord looped through it - Iíll seal the bottom of the tube with some tape to prevent the shock cord from feeding back into the now extended NC ebay...

    Itís ready for priming and painting tomorrow.

    And Iíll probably make a longer cheap cardboard sled for it to lay the EFMini and LiPO on, and maybe some foam if it needs some padding...
    Last edited by snrkl; 26th October 2017 at 02:57 PM.
    Reasonably new to rocketry and hailing from the land down under.. I speak metric... I know not of these feet and inches you speak of...

    QRS: #193
    AMRS: #148

    AMRS L1 (2018-03-18 - Mk4 Rocket Propelled Companion Pod)

  10. #40
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    I suggest a test flight with a lower impulse motor to see if the tracker performs adequately before punching it to out of sight land. The seconds you wait to reacquire the signal after the button is pushed become agonizing. Kurt

  11. #41
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    Quote Originally Posted by ksaves2 View Post
    I suggest a test flight with a lower impulse motor to see if the tracker performs adequately before punching it to out of sight land. The seconds you wait to reacquire the signal after the button is pushed become agonizing. Kurt
    You've hit the nail on the hammer!!

    I actually have two builds hiding in this thread:
    - Aspera-I which is the painted one, fit for an E20-7W and an F39-9T... (sims to 599m and 760m respectively)
    - Aspera-II which is the 3fin shortened version being built for the G80-13T (current design sims to 1370m (~4500') at Mach 1.22)

    The plan for this weekend is to shake down test the EFMini in Aspera-I with the E20 and if all goes well, the F39.. (between the EFMini, Altimeter3 and the F39 RMS case, there is lots to lo$e if it goes pear shaped... I am confident that if nothing else, my chances of getting the nose cone and EFMini back are strong! )

    Aspera-II will design finalised with construction to start next week...
    Reasonably new to rocketry and hailing from the land down under.. I speak metric... I know not of these feet and inches you speak of...

    QRS: #193
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    AMRS L1 (2018-03-18 - Mk4 Rocket Propelled Companion Pod)

  12. #42
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    A supersonic Apogee Aspire...

    Iíve managed to get the EFMini, small 200/220 mAH LiPO and the altimeter 3 into my new extended NC EBay. Total NC weight 64g...

    Finished and ready to fly tomorrow:

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    Iíve opted to go with a 6Ē chute over the Mylar streamer - the Mylar was bringing it down at 32m/s (~100km/h) in the sims - the gps, the NC and the f39 RMS together makes it drop like a stone.

    I figured bringing it down at 16m/s is more likely to result in a second flight and the walking distance with tomorrowís forecasted winds is only 150m... I simmed a 12Ē and it was pushing the 500m walk range which is too far for the GPS maiden / shakedown flight..

    Iíve packed a 110x920mm Fluorescent yellow rip stop streamer (72km/h descent) in case I change my mind. My thinking is with a streamer it will come down nose first with the body horizontal, but Iím not sure I want to try that...

    Plan for tomorrow is to fly maiden on an e20-7W, then the F39T-9 RMS..

    This will be my first E and F class motor flights, my first RMS and my first GPS flights...
    Reasonably new to rocketry and hailing from the land down under.. I speak metric... I know not of these feet and inches you speak of...

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  13. #43
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    TeleGPS and the support hardware is a good chunk of coin, but for money spent you aren't finding a lighter weight, less volume intensive unit, +/-2m precision, RDF radio beacon backup, APRS features, selectable baud rate to increase range over an eggfinder, and offers data recording with verbal call outs. The data telemetry is live feed with mach, velocity, max altitude, headings, current altitude, positions, and records tracking path. You can generate a 3D plot of the flight post flight. 12.3 g tracker. Good for 12 hours off of the 3.7 400mAh lipo. Used it for a university funded L-1 HPR multistage with 29mm and 38mm rockets scratch build 10-20k+ ft alt with drifts for 2miles+ planned. We weren't certain our rockets would even survive being prototypes, so we wanted TeleGPS for its black box capabilities in real time too. About $400-500 start up for all the ground equipment minus a laptop. Hardest part is passing the FCC exam, I scored a 26 and passed by 1 question. You can take an FCC exam for technicians license every 2 months usually at $15.

    If you plan on tracking a lot of high power later it may be worth the investment for a piece of mind. KN4EOU out...

  14. #44
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    Well - ASPIRA-I flew today. Kind of.

    Two failed ignitions on the e20-7Ws before we abandoned he second one had a bunch of black powder in the grain to help kick start it and it still fizzled. Local vendor assured me if we canít get them lit heíll replace them.

    So I built my f39-9 and re-padded it.

    It went like a scalded cat.

    GPS signal was good. We lost site of it but that wasnít surprising.

    Wandered around the coords for a bit and just couldnít find my rocket. Then it dawned on me and I started looking for a nose cone instead of a rocket. Sure enough, I found the NC with the gps, LiPO and A3, but no rocket.

    A quick examination and I discovered the vitamin tube I used to extend the NC: I put the shock cord either side of the mold pour spot, which is the weakest part of the tube - lesson learned - fill the base with epoxy next time.

    So flight 1&2 were scratched, flight 3 resulted in the loss of the airframe and a 24/40 RMS case.


    Sent from my iPhone using Rocketry Forum
    Reasonably new to rocketry and hailing from the land down under.. I speak metric... I know not of these feet and inches you speak of...

    QRS: #193
    AMRS: #148

    AMRS L1 (2018-03-18 - Mk4 Rocket Propelled Companion Pod)

  15. #45
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    Altimeter data Click image for larger version. 

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    Reasonably new to rocketry and hailing from the land down under.. I speak metric... I know not of these feet and inches you speak of...

    QRS: #193
    AMRS: #148

    AMRS L1 (2018-03-18 - Mk4 Rocket Propelled Companion Pod)

  16. #46
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    So with Aspera-I MIA, I guess we start the final design and build for Aspera-II - going higher and faster but with a disposable motor this time.

    Build will take the old NC extension design and strengthen the attachment point.

    My thoughts so far are to lengthen the vitamin tube by 10mm and fill the bottom 8mm of the canister with epoxy.

    Iíll drill holes through canister and epoxy this time for shock cord attachment. Iím wondering if this will be sufficient.

    Other ideas are to use the bottom of the stock NC epoxied into the bottom of the extension - Iíll have to see if thereís enough material to epoxy with any level of trust it will hold.

    Iím also going to (*shock!*) actually do some *maths* to figure out what sort of forces it needs to withstand, and maybe figure out some ground testing pain to put the NC through...

    Pics and drawings to come.


    Sent from my iPhone using Tapatalk Pro
    Reasonably new to rocketry and hailing from the land down under.. I speak metric... I know not of these feet and inches you speak of...

    QRS: #193
    AMRS: #148

    AMRS L1 (2018-03-18 - Mk4 Rocket Propelled Companion Pod)

  17. #47
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    Thats a shame. For the next build there is a note in some Apogee documents that suggest you only need 3 fins not 4 for stability. That will help reduce drag a fair bit.

    I've been working on a scratch built 29mm design similar to the aspire in open rocket, and found I was getting better performance by adding nose weight and reducing fin size. Drag seems to be a lot more critical than minor changes in mass when trying for supersonic.

  18. #48
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    Quote Originally Posted by snrkl View Post
    Well - ASPIRA-I flew today. Kind of.
    [...]So I built my f39-9 and re-padded it.

    It went like a scalded cat.

    GPS signal was good. We lost site of it but that wasn’t surprising.

    Wandered around the coords for a bit and just couldn’t find my rocket. Then it dawned on me and I started looking for a nose cone instead of a rocket. Sure enough, I found the NC with the gps, LiPO and A3, but no rocket.

    A quick examination and I discovered the vitamin tube I used to extend the NC: I put the shock cord either side of the mold pour spot, which is the weakest part of the tube - lesson learned - fill the base with epoxy next time.
    Just to make sure we understand the failure point: your nose-cone shoulder extension, in the form of vitamin tube, failed by way of ...
    ... either that tube disintegrated at the point of shock cord attachment ...
    ... or was it that the shock cord did not epoxy to the tube properly and peeled off?

    Either way, I would avoid using the same materials (fragile or epoxy unfriendly vitamin tube) in the second rocket!


    Quote Originally Posted by snrkl View Post
    Altimeter data Click image for larger version. 

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    How did that compare to your sims?
    If the sims are off/too optimistic, by how much?
    If your goal was to go supersonic, as the thread subject indicates, will you achieve your goal, net of the real world adjustments?

    Personally, I don't care about speed targets, but if that's your goal, you may want to make sure you are on track to achieve it!
    If you are not making it, your only recourse may be to cut the weight.

    Quote Originally Posted by snrkl View Post
    So with Aspera-I MIA, I guess we start the final design and build for Aspera-II - going higher and faster but with a disposable motor this time. Build will take the old NC extension design and strengthen the attachment point.

    My thoughts so far are to lengthen the vitamin tube by 10mm and fill the bottom 8mm of the canister with epoxy.
    I’ll drill holes through canister and epoxy this time for shock cord attachment. I’m wondering if this will be sufficient.
    Are you sure the vitamin tube will not crack and disintegrate at the point beyond which it is filled with epoxy?
    It failed you once before, why rely on it again?

    I would shop for the target diameter fiberglass, phenolic, or cardboard tube, in that order of preference/strength.

    Good luck!
    a
    Last edited by afadeev; 30th October 2017 at 11:41 PM.
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    Radrocketeers.org NAR L2

  19. #49
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    Quote Originally Posted by gwh View Post
    Thats a shame. For the next build there is a note in some Apogee documents that suggest you only need 3 fins not 4 for stability. That will help reduce drag a fair bit.

    I've been working on a scratch built 29mm design similar to the aspire in open rocket, and found I was getting better performance by adding nose weight and reducing fin size. Drag seems to be a lot more critical than minor changes in mass when trying for supersonic.
    Yes, exactly - the G80 version has had three major changes inline with this document:
    1) three fins, not four
    2) Shorter by 115mm (165mm off the aft body tube, but the nose cone is 50mm longer)
    3) Nose cone electronics and NC extension takes the NC to 65g (+17g for the EFMini, +17g for the lipo, +17g for the Altimeter3 (which needs to be replaced now) +~9-10g for the NC extension)
    Reasonably new to rocketry and hailing from the land down under.. I speak metric... I know not of these feet and inches you speak of...

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  20. #50
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    Quote Originally Posted by afadeev View Post
    Just to make sure we understand the failure point: your nose-cone shoulder extension, in the form of vitamin tube, failed by way of ...
    ... either that tube disintegrated at the point of shock cord attachment ...
    ... or was it that the shock cord did not epoxy to the tube properly and peeled off?

    Either way, I would avoid using the same materials (fragile or epoxy unfriendly vitamin tube) in the second rocket!
    As you can see from this pic, it just shattered the aft end of the tube where the mould point is:
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    Had I spent a little more time thinking about it, or (*shock!!*) TESTING it, it would have been clearer to me...

    Quote Originally Posted by afadeev View Post

    How did that compare to your sims?
    If the sims are off/too optimistic, by how much?
    If your goal was to go supersonic, as the thread subject indicates, will you achieve your goal, net of the real world adjustments?

    Personally, I don't care about speed targets, but if that's your goal, you may want to make sure you are on track to achieve it!
    If you are not making it, your only recourse may be to cut the weight.
    This is a very good question, and I have only had a chance to look at the A3 data in detail today:
    SIM:
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    A3Data:
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    Sim took it to 762m, Actual was 702m

    MaxG was simmed to 31Gs, you can see where the A3 peaked at 24G (it's rated Max) so for all intents and purposes, it looks like the flight up was nominal and within a small margin of error on the altitude..


    Quote Originally Posted by afadeev View Post
    Are you sure the vitamin tube will not crack and disintegrate at the point beyond which it is filled with epoxy?
    It failed you once before, why rely on it again?

    I would shop for the target diameter fiberglass, phenolic, or cardboard tube, in that order of preference/strength.

    Good luck!
    a
    This is where the A3 data is quite useful - we can see from this that the NC took an 8G force at ejection (and 12Gs when it landed solo on the ground).. This at least gives me something to test on the ground..

    Current thinking is to look at whether a card stock bulkhead disk sandwiched in epoxy at the tail end of the tube will make it suitably strong enough... I figure I subject it to 16Gs (twice the measured force from the F39 ejection charge) and see what happens.. If it holds up (and *if* my testing method is sound..) I figure I can tick that box off and move onto the next design/construction element..

    Given my current luck with corn fields, I am wondering how small I can make a sonic screecher of some kind...
    Last edited by snrkl; 31st October 2017 at 01:32 PM.
    Reasonably new to rocketry and hailing from the land down under.. I speak metric... I know not of these feet and inches you speak of...

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  21. #51
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    Interesting - the more I look at that A3 data, the more I think the NC didn't separate till the VERY end...

    A 65g nose cone took 45 seconds to land from an altitude of 700m... descending at ~20m/s...

    That't the same speed as this rocket coming down on a streamer...

    By a few online calculators, a 65g nose cone should fall from 700m in 11 sec... Flight profile shows it took 45 secs to land:

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    Reasonably new to rocketry and hailing from the land down under.. I speak metric... I know not of these feet and inches you speak of...

    QRS: #193
    AMRS: #148

    AMRS L1 (2018-03-18 - Mk4 Rocket Propelled Companion Pod)

  22. #52
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    Looking at the A3 data, it appears that there is a large G load shortly before it hits the ground.

    Perhaps, and this is just a thought, at apogee the ejection charge G load was enough to crack the mount but not separate the nose cone yet. Then the parachute didn't open until it was near the ground, where the jolt of it opening finished separating the nose cone and fell free.

    If that's more or less what happened, then the rest of the rocket would be nearby though.
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  23. #53
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    Quote Originally Posted by Cabernut View Post
    Looking at the A3 data, it appears that there is a large G load shortly before it hits the ground.

    Perhaps, and this is just a thought, at apogee the ejection charge G load was enough to crack the mount but not separate the nose cone yet. Then the parachute didn't open until it was near the ground, where the jolt of it opening finished separating the nose cone and fell free.

    If that's more or less what happened, then the rest of the rocket would be nearby though.
    I think the data supports the hypothesis - if we look at the last 5secs of the data in more detail:

    Click image for larger version. 

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    I think the 12G load at 46.8sec could be the chute finally opening (it was only a small 6" estes plastic") at an altitude of 11m... If you look at the Gforce data after, there is a 5G spike that could be impact of the NC, followed by a reading where the GForce drops below 1 (NC going weightless as it reached it's "bounce apogee") then it lands and settles to 1G resting on the ground....

    The only part I don't get is, if the NC only separated 11m of the ground, : WHERE THE HELL WAS MY ROCKET?!?!

    ;^)
    Reasonably new to rocketry and hailing from the land down under.. I speak metric... I know not of these feet and inches you speak of...

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    AMRS L1 (2018-03-18 - Mk4 Rocket Propelled Companion Pod)

  24. #54
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    Quote Originally Posted by snrkl View Post
    I think the data supports the hypothesis - if we look at the last 5secs of the data in more detail:

    Click image for larger version. 

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    I think the 12G load at 46.8sec could be the chute finally opening (it was only a small 6" estes plastic") at an altitude of 11m... If you look at the Gforce data after, there is a 5G spike that could be impact of the NC, followed by a reading where the GForce drops below 1 (NC going weightless as it reached it's "bounce apogee") then it lands and settles to 1G resting on the ground....

    The only part I don't get is, if the NC only separated 11m of the ground, : WHERE THE HELL WAS MY ROCKET?!?!

    ;^)
    I would think that would be too close together for any conclusion to be drawn. I would guess the fraction of a second lag was just from the vent holes trying to keep up with the difference in pressure. The nose cone part makes no sense to me though- why the nose cone would fall so slowly if it wasn't tethered to anything.

    By the way, kph is NOT an SI unit! m/s all the way! (is it weird that I know the speed of sound in m/s- it's almost exactly 340m/s- but nowhere near as well in mph or kph? That's what comes of too much Kerbal Space Program...)
    NAR #104043, Jr L1 - 3/18/18
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  25. #55
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    Quote Originally Posted by snrkl View Post
    Interesting - the more I look at that A3 data, the more I think the NC didn't separate till the VERY end...

    A 65g nose cone took 45 seconds to land from an altitude of 700m... descending at ~20m/s...

    That't the same speed as this rocket coming down on a streamer...

    By a few online calculators, a 65g nose cone should fall from 700m in 11 sec... Flight profile shows it took 45 secs to land:

    Click image for larger version. 

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    How did you determine that the 65g nose cone should have an average terminal velocity of ~60 m/s? What is the CdA? Are you sure the nose will fall ballistic, or maybe it will be unstable and tumble?

  26. #56
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    Quote Originally Posted by Buckeye View Post
    How did you determine that the 65g nose cone should have an average terminal velocity of ~60 m/s? What is the CdA? Are you sure the nose will fall ballistic, or maybe it will be unstable and tumble?
    It is a good question: A little intuition and some assumption.. I can't see this particular nose cone tumbling, certainly not for 45secs... It is of course possible, but for my money, for the NC to tumble at the same speed as an the airframe was simmed to on a streamer, I would be surprised...

    Incidentally, the video of said "Scalded Cat" disappearing from the pad is here:


    https://youtu.be/fScNJUx8ckg?t=1386
    Reasonably new to rocketry and hailing from the land down under.. I speak metric... I know not of these feet and inches you speak of...

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  27. #57
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    Aspera II - G80 and (hopefully) Supersonic

    So I have had 5 minutes to scratch myself finally, and have had time to carry the proposed changes to the airframe for Supersonic into OR:

    ORK: OR_ApogeeAspire_G80_coloured.ork

    And pics for those that can't see it...
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    Changelog:
    1) Use a stronger coupler than the stock one supplied - after watching how much flex the last one had between the MMT and the coupler, I feel a little more strength is worth the marginal increase in weight.
    2) Shortened the aft BT to be exactly the right length for the G80 - this way, the engine block will butt up against the aft coupler.
    3) reverting to the mylar streamer - I would rather get it back with a busted fin than risk it doing a Houdini act again...
    4) Planning to keep the vitamin tube NC base - this time with epoxy+cardboard bulkhead reinforcement. This construction will be WELL tested - just need to figure out the best way to test it for 8-16Gs of sudden stopping power...

    The Updated design sims as follows:
    Click image for larger version. 

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    Reasonably new to rocketry and hailing from the land down under.. I speak metric... I know not of these feet and inches you speak of...

    QRS: #193
    AMRS: #148

    AMRS L1 (2018-03-18 - Mk4 Rocket Propelled Companion Pod)

  28. #58
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    So some progress tonight.

    Fins are papered and drying (one got a little wrinkly but Iíll sort it when I CA them (sand and ReCA)

    Click image for larger version. 

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    Iíve also laid 5min epoxy and cardstock bulkheads on either side of the NC extension (vitamin) tube.

    Click image for larger version. 

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    Contact surfaces on the tube and card stock were well scored to improve mechanical adhesion capabilities.

    I have plans to test it for holding 65g of nosecone and electronics under an 8-16G sudden stop - I figure Iíll load it up and try a throw/yank manoeuvre and see what the A3 registers for g force...

    Canít think of anything more suitable - if anyone has any ideas Iím all ears...
    Reasonably new to rocketry and hailing from the land down under.. I speak metric... I know not of these feet and inches you speak of...

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    AMRS L1 (2018-03-18 - Mk4 Rocket Propelled Companion Pod)

  29. #59
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    A supersonic Apogee Aspire...

    NC reinforcements done.

    Only added 3.6g of weight.

    NC bulkhead base increased in thickness from 1mm to 7mm.

    Click image for larger version. 

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    Tested it fully loaded using a drop/yank test standing on a chair.

    Used the A3 to record g force (SCIENCE!!)

    Click image for larger version. 

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    Eight tests done (only attached charts from the last 4)

    Tested at Gforce loads from 8-13Gs.

    Nose coneís new attachment point didnít even break a sweat.

    Itís not going anywhere on the next flight. Well... nowhere that the rocket airframe wonít follow anyhow...
    Last edited by snrkl; 8th November 2017 at 06:57 AM.
    Reasonably new to rocketry and hailing from the land down under.. I speak metric... I know not of these feet and inches you speak of...

    QRS: #193
    AMRS: #148

    AMRS L1 (2018-03-18 - Mk4 Rocket Propelled Companion Pod)

  30. #60
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    It is a good question: A little intuition and some assumption.. I can't see this particular nose cone tumbling, certainly not for 45secs... It is of course possible, but for my money, for the NC to tumble at the same speed as an the airframe was simmed to on a streamer, I would be surprised...
    A nose cone will almost certainly tumble, particularly a tail-heavy one (as yours probably is, given the Eggfinder). Maybe not a fast end-over-end tumble, but it won't be ballistic. Your simmed streamer speed (32 m/s) seems way too high. I suspect you aren't accounting for the tumbling drag of the separated airframe itself (OR does not do this by default, and on all but the smallest rockets, airframe drag will overwhelm streamer drag)? On my cardboard framed high power rockets, "drogueless" descent speed is more like 15-20 m/s (OR sims much higher than that).

    I aim at the stars. But sometimes I hit London.

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