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  1. #1
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    "Mk4 Rocket Propelled Companion Pod" - SCR Quake L1 Build Thread...

    OK - so I figure if I am building my SCR quake to take a 29mm motor, I may as well look at L1 certifying with it.

    I've considered all the advice I have read that encourages L1 certifications on a 4" airframe to keep things low and recoverable, but I figure I have it, I am building it, so why not...

    It's a pretty simple kit - 3FNCwith thick cardboard tubing, 3mm TTW plywood fins and a plastic NC.

    Click image for larger version. 

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    On an H135 it is simming to around 3000', so the plan is to fly it with a JLCR, Eggfinder Mini and JLA3...


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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

  2. #2
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    Quote Originally Posted by snrkl View Post
    OK - so I figure if I am building my SCR quake to take a 29mm motor, I may as well look at L1 certifying with it.

    I've considered all the advice I have read that encourages L1 certifications on a 4" airframe to keep things low and recoverable, but I figure I have it, I am building it, so why not...

    It's a pretty simple kit - 3FNCwith thick cardboard tubing, 3mm TTW plywood fins and a plastic NC.

    Click image for larger version. 

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    On an H135 it is simming to around 3000', so the plan is to fly it with a JLCR, Eggfinder Mini and JLA3...


    Click image for larger version. 

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    If you can track an Aspire you can track anything... I'm planning on a nice low and slow baby H for my L1... Low and slow for most rockets that is! My planned L1 sims to 4k and weighs only 13ish oz (400g for you). LOC 38mm tube with a 29mm MMT. Flew it on a G80 awhile ago, that didn't stick around for long!

    Sent from my LGL44VL using Rocketry Forum mobile app

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  3. #3
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    So kit deviations:

    I知 planning on putting internal fillets in (figure it痴 a skill I知 gonna need) so that changes to construction steps a little.

    I値l also be butchering the NC to figure out some kind of av sled.

    Taking guidance from @cerving I知 worried about EFminis and all thread. I need to look at how they interact a little as I get to the NC part.


    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

  4. #4
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    If you fail the cert don't worry just try again. You'd save a bit of coin if this works out okay. Don't skimp on the shock cord. Wish I bought a onebadhawk harness first time. Kevlar cords don't melt as easy. Normally the HPR kits are built tougher out of 1/16" to 3/32" fiberglass or CF on fins with thin wall airframe tubing for H-I flights.

  5. #5
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    Dry fit MMT for length. The fins are for the 24mm version, so there痴 a few mm to be shaved off the tab to make it fit depth wise.

    Click image for larger version. 

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    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

  6. #6
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    You might want to size a pressure relief hole so the nosecone won't pop off. Try to not skimp on a quality epoxy such as Rocketpoxy G5000, Aeroepoxy, Proline, or Cotronics. The Cotronics 4525 and 4700 are typically for pushing Mach 2-3+ with 500-600F thermal ratings, rather expensive, and are actual aerospace epoxies so buying those for this project is a waste. Letting you know about the Cotronics incase you want to build something super fast someday.

    Nomex or Cellulose wadding material is highly recommended to save the chute because the delay charges range from 0.6 g to 1.0 g and you don't want the chute burning.

  7. #7
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    "Mk4 Rocket Propelled Companion Pod" - SCR Quake L1 Build Thread...

    MMT front end epoxied and drying.
    Click image for larger version. 

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    I知 using 5min epoxy for this build - HW store only had 5min or 1-3hr epoxy - and I知 not that patient.

    I値l need to get some 15min from my local rocket vendor when I next think of it.

    For what this rocket is doing though, I知 confident 5min will be ok. I値l be using something more flowy like 15min for internal filets.


    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

  8. #8
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    Quote Originally Posted by Andrew_ASC View Post
    You might want to size a pressure relief hole so the nosecone won't pop off. Try to not skimp on a quality epoxy such as Rocketpoxy G5000, Aeroepoxy, Proline, or Cotronics. The Cotronics 4525 and 4700 are typically for pushing Mach 2-3+ with 500-600F thermal ratings, rather expensive, and are actual aerospace epoxies so buying those for this project is a waste. Letting you know about the Cotronics incase you want to build something super fast someday.

    Nomex or Cellulose wadding material is highly recommended to save the chute because the delay charges range from 0.6 g to 1.0 g and you don't want the chute burning.
    Glue details in last post (coincidence).

    Nomex and cellulose dog barf planned. The nomex I bought is too big (12) so I値l see if my local vendor can sub for something more suited to this airframe.




    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

  9. #9
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    I知 planning on discussing glue for the retainer with my local vendor (it痴 one of their kits) to see if they think it will be ok with regular epoxy for the retainer or something more heat resistant is needed.

    I have a feeling they usually recommend jbweld for the retainer but I値l have to check.


    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

  10. #10
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    Five minute might work for one flight on an H if it's real liberally applied. RSO dependent. We subbed some on my L-1 and the shock cord failed holding a half kilogram nosecone on not the epoxy. However the five minute epoxy did not like the heat loading at all and wasn't fully stuck to surface after the ejection charge had fired. I'd used rocketpoxy on the rest and the airframe survived a mile fall. JBweld might do okay for a few flights.

  11. #11
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    5-minute epoxy will work fine for this paper/wood rocket on H motors. Expensive epoxies are overkill. A good wood glue will work too. Fillets will be better with a 20-minute and JB weld is probably a good idea for the retainer. I've used regular epoxy on the Estes plastic retainers with good luck.
    Dick Stafford
    The member formerly known as the Pointy-Haired Moderator.
    The Original Rocket Dungeon
    Volunteer compiler of product news for ROCKETS Magazine

  12. #12
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    Quote Originally Posted by rstaff3 View Post
    5-minute epoxy will work fine for this paper/wood rocket on H motors. Expensive epoxies are overkill. A good wood glue will work too. Fillets will be better with a 20-minute and JB weld is probably a good idea for the retainer. I've used regular epoxy on the Estes plastic retainers with good luck.
    That was my thinking...

    I appreciate all the advice (so keep it coming folks!)

    The thing I知 liking about the whole learning process is getting the hands on knowledge of what will hold versus what won稚.

    I don稚 mind mistakes that result in failed flights - that for me is the learning in action!


    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

  13. #13
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    Quote Originally Posted by rstaff3 View Post
    5-minute epoxy will work fine for this paper/wood rocket on H motors. Expensive epoxies are overkill. A good wood glue will work too. Fillets will be better with a 20-minute and JB weld is probably a good idea for the retainer. I've used regular epoxy on the Estes plastic retainers with good luck.
    Yeah, wood glue is really strong on wood/paper. My L1 rocket will eventually go mach and a mile on an H255 so I did some stress testing- I got about 500kPa shear strength at the root with no internal fillets other than liberal glue and "double butter." For your rocket that's 80 newtons ish lateral drag or 8ish kg on the center of the fin. In other words, plenty.

    The one caveat since this is a cert flight: A suboptimal landing is not going to be good for this method. However if you land hard you probably failed the cert already, so it just means you can't fly again on the same day. There's something to be said for popping a fin off rather than snapping it if you're a patient person.



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  14. #14
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    Speaking of learnings, I once went to dinner as a colleagues +1 as his wife was out of town.

    The couple who痴 house we were in, the husband was a civil engineer who built highways.

    He had a massive aerial photo book of the highways he壇 built, and each picture came with a story that started 渡ow this is the highway where I learned that... and we would hear the failure story that went with the picture of what broke and what he壇 learned.

    After about 30mins of this, my colleague said to him:
    的知 glad to hear that you致e learned to build roads the same way we致e learned to build computer networks...




    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

  15. #15
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    "Mk4 Rocket Propelled Companion Pod" - SCR Quake L1 Build Thread...

    Dry fit of the MMT and fins.

    Fins needed a little sanding on the tabs as they were a little fat for the laser cut slots.

    Click image for larger version. 

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    The fins are 2mm too tall (fins are cut for a 24mm MMT - I知 using a 29mm)

    Marked all three fins and measured to be sure. Exactly 2mm needs to be taken from the tab on each fin.

    Also used a neat tape trick a fellow club member showed me for making sure you can get the rear CR out to do fillets.

    Click image for larger version. 

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    So now I sand the fin root edges. I知 breaking out the belt sander and inverting it for this.
    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

  16. #16
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    Yep, if done right wood glue bond is stronger than the substrate.
    Dick Stafford
    The member formerly known as the Pointy-Haired Moderator.
    The Original Rocket Dungeon
    Volunteer compiler of product news for ROCKETS Magazine

  17. #17
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    Quote Originally Posted by snrkl View Post
    Dry fit of the MMT and fins.

    Fins needed a little sanding on the tabs as they were a little fat for the laser cut slots.

    Click image for larger version. 

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    The fins are 2mm too tall (fins are cut for a 24mm MMT - I知 using a 29mm)

    Marked all three fins and measured to be sure. Exactly 2mm needs to be taken from the tab on each fin.

    Also used a neat tape trick a fellow club member showed me for making sure you can get the rear CR out to do fillets.

    Click image for larger version. 

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    So now I sand the fin root edges. I知 breaking out the belt sander and inverting it for this.
    Stop posting while I edit! Accidentally hit post halfway through typing... Darn phone...

    Aside- I like the portal theme!

    Sent from my LGL44VL using Rocketry Forum mobile app
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  18. #18
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    Quote Originally Posted by LithosphereRocketry View Post
    Stop posting while I edit! Accidentally hit post halfway through typing... Darn phone...

    Aside- I like the portal theme!

    Sent from my LGL44VL using Rocketry Forum mobile app
    LOL: 都nrkl aerospace - we build live while pundits post...

    I like it... it痴 like model rocketry reality channel...

    Actually. I hate reality shows and everything they stand for...

    Ignore what I just said and let us never speak of this again...



    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
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  19. #19
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    sand the fins smooth, then adjust the fin slots as needed.
    Rex
    L2-competitor 3, AT J350W, 8/27/2016, Bong, 2557'
    my youtube channel http://www.youtube.com/channel/UC0gB...?feature=watch

  20. #20
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    Quote Originally Posted by Rex R View Post
    sand the fins smooth, then adjust the fin slots as needed.
    Rex
    Thanks Rex - for this build, I sanded down the tabs a little with 320grit - it didn't take much to get them to fit.. I am a little wary of adjusting the slots - I must have had the kit bag standing on it's end at some stage and one of the slots already has a wrinkle between the aft of the slot and the base of the airframe - I don't want to do anything more that might weaken it..

    I can certainly see how your advice would be the right way to do it as I head into more HPR stuff..
    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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  21. #21
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    CWF and sanded a few dings / chips in two of the fins.

    Click image for larger version. 

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    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

  22. #22
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    Final dry fit.

    Click image for larger version. 

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    Build halted at this point. I remembered launch lugs before it was too late (phew!) and I致e decided to put 1010 rail buttons on it.

    I need to order some buttons so I figure I値l order some more runny epoxy for the internal fillets also.

    I致e got queries into my local vendor on which epoxy they sell for internal fillets and to find out if the rail buttons they sell come with nuts, or if I have to get them separately.


    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...

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  23. #23
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    there seems to be two (main) schools of thought on how wide to make them (kit makers) Estes thinks that 'we' should do our sanding after installation and thus their slots are sized to match the fin thickness before sanding. the other school of thought knows that plywood fins are a royal pain to sand after they are installed and so under sizes the slots. slots are fairly easy to make wider, a rotary tool w/ a sanding disk makes short work of removing a hairs breadth of material (and a power sander makes sanding fins easy).
    I tend to use 20 minute epoxy for most jobs and j b weld for aluminum motor retainers.
    Rex
    L2-competitor 3, AT J350W, 8/27/2016, Bong, 2557'
    my youtube channel http://www.youtube.com/channel/UC0gB...?feature=watch

  24. #24
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    Here is what I am aiming for with this build (except, not the "moving horizontally under thrust" part.. that's just artistic license at play... )


    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

  25. #25
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    Other then "getting up there" on an H motor, I don't see any reason you can't do a L1 cert with this rocket. The JLCR really makes it much easier and a shorter walk. Have you considered an I motor?

    I agree with 5 min. epoxy being plenty for this build. I have a 29mm MMT PML Callisto I built 14 years ago with 5 min. epoxy and it's still holding up just fine to H motors and hard landings. The 5 min epoxy has held up fine with the fiberglass fins and quantum tubing. I'm sure it will do even better with cardboard and plywood where it can soak in a little.

    Good luck with the cert.
    Handeman

    TRA #09903 L3 3/29/2015

    "If you don't use your head, you have to use your feet!" my Dad

    Tripoli Central Virginia #25 - BattlePark.org

  26. #26
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    My GF did her L1 cert on a Darkstar Mini with a pro 29 3 grain (so 38mm rocket, 29m motor) broke mach and a mile and it was just fine. exciting flight too! my advice for your L1: Fly the rocket you want to fly, and have fun with it.
    Tom
    NAR #83620 L2 soon to be L3 :rolleyes:

  27. #27
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    Quote Originally Posted by Yoehahn View Post
    My GF did her L1 cert on a Darkstar Mini with a pro 29 3 grain (so 38mm rocket, 29m motor) broke mach and a mile and it was just fine. exciting flight too! my advice for your L1: Fly the rocket you want to fly, and have fun with it.
    What motor? I can't think of any motor that would get that size rocket up a mile & mach... 6 grain, sure. But I haven't been able to find a 3g motor that goes much over 4k/m0.8 in that size rocket. I haven't been simming the DSmini but my rocket is 13oz dry, 38mm by 3ft ish, so similar to what I'm picturing for the DS.

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  28. #28
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    Quote Originally Posted by LithosphereRocketry View Post
    What motor? I can't think of any motor that would get that size rocket up a mile & mach... 6 grain, sure. But I haven't been able to find a 3g motor that goes much over 4k/m0.8 in that size rocket. I haven't been simming the DSmini but my rocket is 13oz dry, 38mm by 3ft ish, so similar to what I'm picturing for the DS.
    We used a CTI H410 Vmax, single deploy, with beveled leading and trailing edges. this was about 4-5 years ago, not sure if the kit has changed at all but If I remember we hit close to a mile but just under.
    Tom
    NAR #83620 L2 soon to be L3 :rolleyes:

  29. #29
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    I've flown one of the similar size kits with a 24mm CTI 6G G65, just with an added section of tube as a camera/payload bay. Great flight and easily recoverable without too long a walk on a pretty calm day, with a JLCR and built with epoxy I wouldn't see this having any problem with many H motors.

    If you really want to knock a few feet of the max altitude a payload bay might be worth a look, shouldn't cost much to get a bit of body tube and a coupler to suit and gives a spot for a little weight, altimeters or camera and is easy to remove if you want to fly smaller motors.

  30. #30
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    Quote Originally Posted by Andrew_ASC View Post
    If you fail the cert don't worry just try again. You'd save a bit of coin if this works out okay. Don't skimp on the shock cord. Wish I bought a onebadhawk harness first time. Kevlar cords don't melt as easy. Normally the HPR kits are built tougher out of 1/16" to 3/32" fiberglass or CF on fins with thin wall airframe tubing for H-I flights.
    This must be a closely guarded secret. Not even LOC, Binder Design, or Madcow know this. My level two was a paper bird.

    A nose cone bay should be relatively easy. The same size centering rings that fit the rocket should fit in the nose cone above the shoulder, at least that has been my experience. You will have to chop the base off to get acess of course. Depending on how you want it installed and what not, you won't necessarily need a tube inside. I just happen to be working on a 2.6" kit myself and will be putting a bay in the nose cone.

    JB Weld will work fine on the retainer for more than just a few flights. I've used it on several, still holding on.
    Wood glue would be better on paper birds but 5-minute will work fine as well. You don't need Rocketpoxy on this bird. In three instances I have had the stuff let go, and it was just holding PEM nuts two of those times, 1/4" threaded rod the other. Maybe I got a bad batch but it broke me from using the stuff.. My Wildman Sport was built with 5-minute and came in ballistic. Nose cone scuffed up but unharmed otherwise. I have since started using US Composites thick stuff with different fillers depending on the task however.

    Nothing is foolproof to a sufficiently talented fool.
    TRA #16513
    Level 1: Danger Close ---AT H123W to 1240'--- 29 OCT 2016
    Level 2: Binder Design Tyrannosaur ---AT J315R to 2148'--- 30 SEP 2017

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