Back After 50+ Years

[Caley]

Hello I'm Caley Ann,

I am looking for help to ensure I obtain all the components for my Level 1 Certification, and eventually Level 2 Certification.

First of all, here's a little of my history. I first got interested in anything that had to do with space or rockets back in 1957 when I heard on the radio about the Russians launching the first satellite, Sputnik 1. From that point on it was almost an obsession, to the point where I dreamed of becoming an astronut. But economics during my childhood never allowed for much more than dreaming.

During my 24 year career in the US Air Force, I did get a chance during my first hitch to try out a few Estes rockets, a Sprint, an Alpha, and a two stage rocket. They all flew just great. Unfortunately for the upper stage of the two stager, that drifted over the trees, never to be seen again. But my career got going strongly, and I had to forego any other involvement in the hobby.

Now, in my waning years, I happened across YouTube, and a lot of videos on the subject, I was totally awed by how far the hobby has come. I attended Roctober last year a the Lucerne Dry Lake Bed, and got more experience, enough to purchase my first beginners kit, a stretch Blobbo. That has been built, and am just awaiting a weekend that is free, so I can attend the gathering on a saturday. If this goes well, I wish to try going for my Level 1 Certification, and maybe eventually a Level 2. That's where I would have to stop because economics still limits me to what I can do.

I believe I am going to purchase a "Torrent", the reason being that it can be used for both certifications.

But I need help when it comes to fully outfitting and supplementing the standard kit with whatever else will be needed. I browsed the Apogee website, and it left me more confused than it enlightened. I was wondering if someone could provide me a laundry list of what I will need to make this ship complete for both levels of certification, items that will hopefully help me attain those two goals.

But I think that I first need to gather everything needed to construct the airframe. I can forego the electronics for now, as I plan on flying it without dual deployment, based on the video Apogee provided on YouTube.

Anyway, I am hoping the flight(s) of my little Blobbo will be enough to help me catch the bug again, and move me on to bigger and better fun. Thanks for any help you can provide.

Caley Ann sometimes known as a spacenut

 

[dhbarr]

Welcome back!

 

[rharshberger]

Welcome back!

 

[Tim51]

Your story reminded me of the film 'October Sky'. Welcome back and the very best of luck with your L1 & L2 certifications!

 

[samb]

Welcome to the party ! Here are some random thoughts I have about your questions.

Apogee is a fine vendor with an excellent reputation for customer service. I've seen the Torrent used for certification flights and it a good tough rocket.

Have you watched the 10-part video series ? Lots of questions answered there: https://www.apogeerockets.com/Advanced_Construction_Videos/Rocketry_Video_61

Have you joined a club affiliated with one of the national organizations that administer the certifications ? You will get alot of good advice here but having a local mentor is key IMHO. https://www.tripoli.org/Certification
https://www.nar.org/high-power-rocketry-info/

The Torrent kit is a pretty complete package but I would suggest adding the purchase of a 29mm-to-38mm motor adapter. There are many L1 motors in the smaller diameter to choose from when the time comes.
https://www.apogeerockets.com/Build...dy_Tubes_29_to_54mm/Motor_Mount_Kit_29mm_38mm

Fly the heck out of your Stretch BLOBBO with as many different motors as you can, especially the Aerotech 24mm composites.

Hope that helps some and good luck !

 

[Caley]

Everyone, Thanks for the nice welcome. Yes, I am from that "October Sky" era.

I already paid for my membership with the Tripoli organisation. I'm just waiting for my membership card before going online and joining ROC. I was filling out their paperwork online when I came to the membership number required, so I had to forego registration until I get that piece of information.

I plan on having an experienced modeler take a look at my Blobbo airframe to ensure it is adquate. I had difficulties determining the CP. CG was easy, but I had never heard of CP. I finally did the cardboard cutout method which told me my CG was behind the CP. I ended up watching another Apogee video to learn how to add nose weight, epoxy and BB's.

I eventually want to determine how high the Blobbo goes. One reason is I don't want it going too high. I have pretty bad eyesight, so I need to keep things lower than most people usually want to fly. When I go to high powered rockets, I will invest in a tracker system. The reason I will do this is I used to have another hobby, free flight rubber power model airplanes. Even with models with wingspans of over 40 inches, they got so high that without others helping me track the model, I would end up losing it. These model rockets are much smaller than some of these model airplanes when it comes to surface area.

Unfortunately I probably overbuilt the Blobbo. It weighs in at a hefty 10.2 ounces without motor. Not sure the recommended motors that I purchased, ESTES E9-4 and D12-3 will be robust enough to propel it off the pad stably. I guess I can only try.

Thanks again Everyone

Caley Ann

 

[Caley]

BTW, I did watch part of that video series. I need to watch them again in order, and do the build along with those videos. Caley Ann

 

[rockets]

Welcome to TRF and welcome back to the hobby!!
Thanks,

 

[DavidMcCann]

Unfortunately I probably overbuilt the Blobbo. It weighs in at a hefty 10.2 ounces without motor. Not sure the recommended motors that I purchased, ESTES E9-4 and D12-3 will be robust enough to propel it off the pad stably. I guess I can only try.

D12-3 should be OK (I cant be sure obviously but 10oz shouldn't be an issue for it) I'd stay away from using an E9 with that weight. I've had.... issues in that range with that motor.

 

[kcobbva]

Caley,

Welcome! So I must say I've been VERY pleased with the Torrent and it will DEFINITELY take L1 and L2 motors (although smaller L2). I've tried to rip the fins off unsuccessfully so far. I did my L1 with it as dual deploy and it works wonderfully. It'll do fine with a single chute for L1 and dual for everything else. I will say that the videos will talk you into using Fixit Epoxy for fin fillets. I would advise against that. They become brittle in those bonded areas. I had one crack and repaired. ALL my other rockets use RocketPoxy and I find it far superior and have never had any issues at all. I also used that to repair it and it's just a rock solid rocket.

Regardless of what you choose to use, welcome to the forum and GO BLUE. Was AF for a while myself. Here's an old thread I did on mine if it's of any use: https://www.rocketryforum.com/showthread.php?130188-My-First-level-one-Rocket&highlight=torrent

it'll even stand till the cows come home: https://youtu.be/RakQCEEDC5c

Kevin

 

[Caley]

Kevin, thanks for the talk on the "Torrent". It does look like a good model to start out with. Also, thanks for the tip on the FixIt eposy. I am wondering if regular 30 minute epoxy would be ok. That's what I used on the Blobbo. Using it just means that I can only do so much work each day, but building something that is going to fly is not something you want to rush through. I know, because I build model airplanes that need to be perfect in order to fly free under rubber power. At my age, I have lots of patience.

Anyone have suggestions on rocket motors for my Stretch Blobbo. I only want it to go about 800-1000 feet high so that I don't lose sight of it.

I imagine that many of us are former USAF or military. It was something that taught me a lot more than what I learned in school.

 

[smugglervt]

Download Openrocket, a free rocket simulation program, to help with your rocket designs and motor selection. https://openrocket.sourceforge.net

Or try thrustcurve: https://www.thrustcurve.org

 

[75Grandville]

Welcome back!

One option is to use Rocksim (30 day trial from Apogee) or OpenRocket (free) to simulate flights with various engines. Openrocket is available here: https://openrocket.sourceforge.net/

Someone already submitted a design file here: https://www.rocketreviews.com/file-27374/oop_vb_stretch_blobbo.rkt

I added about 3 oz nose weight to the design above. A D12-5 will put you at about 300', an E15-7 will send you to 1,200'. An E12-6 will go ~600'.

If you do some searching, you'll see threads about E9's failing - for what that's worth.

Lots of options - have a blast!

 

[kcobbva]

Kevin, thanks for the talk on the "Torrent". It does look like a good model to start out with. Also, thanks for the tip on the FixIt eposy. I am wondering if regular 30 minute epoxy would be ok. That's what I used on the Blobbo. Using it just means that I can only do so much work each day, but building something that is going to fly is not something you want to rush through. I know, because I build model airplanes that need to be perfect in order to fly free under rubber power. At my age, I have lots of patience.

Anyone have suggestions on rocket motors for my Stretch Blobbo. I only want it to go about 800-1000 feet high so that I don't lose sight of it.

I imagine that many of us are former USAF or military. It was something that taught me a lot more than what I learned in school.

Caley,

My personal opinion and others can weigh in here, i wouldn't be as comfortable flying the Torrent as hard as I have had I used bob smith epoxy. That rocketpoxy for I believe $35.00 is really a go to epoxy for me, and for the price I paid for the torrent, protected the investment. I'll use BS on smaller rockets, but not on ones that will take much larger motors.

I've not seen the blobbo except for a quick cursory look a moment ago, but if you really want to fly it high, and if you can really ask the easter bunny for a present, look at the Jolly Logic Chute Release. I fly our lighter single stage rockets up to 2K easily and use the chute release to open at 5 or 600 feet. As long as you remember to turn it on and set it....:bang: it works great and gives you the ability to enjoy high flights yet low recoveries so it doesn't go off to the next state.

 

[Caley]

How long does the two pint rocketepoxy last. Is there enough to do something as big as the "Torrent"?

I looked at the Jolly Logic Chute Release. If one of my rockets were to go up to 1500 feet, and set the Release for say 700 feet, that means the rocket is flopping around for 800 feet, gaining speed as it goes. I wonder just how much of a strain that puts on everything at the higher speed it has gained? I've read that recovery systems can just come apart if they are released at high speeds.

Talking about recovery systems. The "Torrent" can do dual recovery, drogue and main. As I understand it, the rocket ejection charge deploys the drogue. An altimeter deploys the main(s). I read somewhere that you need to purchase black gun powder for that deployment charge. I don't know anything about this system. Just how do you keep the black gun powder in one place, and how is it ignited? Is there somewhere, where I can watch a video of the setup of this system, and possibly see a ground test of how it works?

Right now I am just trying to educate myself. This isn't quite as complex as my observatory and astrophotography, but it is pretty darn complex. Caley Ann

 

[dhbarr]

Breaking open and flapping actually causes quite a bit of drag. Lots of folks using JLCR in this size range.

Typically the BP charges ( and their initiators) go in a small container such as a charge cup, plastic tube, or the tip of a latex gloves finger ( yes really!).

They're set off by a small flight computer which typically reads air pressure to determine altitude.

Definitely keep reading, definitely attend club events. A lot of this stuff clicks the first time you see someone assemble an electronics bay.

 

[Cl(VII)]

How long does the two pint rocketepoxy last. Is there enough to do something as big as the "Torrent"?

I looked at the Jolly Logic Chute Release. If one of my rockets were to go up to 1500 feet, and set the Release for say 700 feet, that means the rocket is flopping around for 800 feet, gaining speed as it goes. I wonder just how much of a strain that puts on everything at the higher speed it has gained? I've read that recovery systems can just come apart if they are released at high speeds.

Talking about recovery systems. The "Torrent" can do dual recovery, drogue and main. As I understand it, the rocket ejection charge deploys the drogue. An altimeter deploys the main(s). I read somewhere that you need to purchase black gun powder for that deployment charge. I don't know anything about this system. Just how do you keep the black gun powder in one place, and how is it ignited? Is there somewhere, where I can watch a video of the setup of this system, and possibly see a ground test of how it works?

Right now I am just trying to educate myself. This isn't quite as complex as my observatory and astrophotography, but it is pretty darn complex. Caley Ann

The JL Chute Release is an excellent option for easy DD recovery. The parts will flop around , but with few exceptions will not become stable and thus pick up too much speed. For a rocket like the Torrent (cardboard, so more open to damage by zipper) I would probably put an 18" or 24" chute on the shock cord that will be able to open while falling (drogue chute), and just bundle the Main chute (48" or 60" depending on how heavy you build and what surface you will be landing on) with the Chute Release. Altimeters are great, and I swear by my Missileworks RRC3s, but the chute release has changed the way I fly some rockets. I flew a rocket to about 14k' last year and did DD with a chute release.

The suggestion of going to a club launch, and just sitting around as people prep rockets and watching is a good one. Many folks will be glad to talk you through what they are doing also.

Also, welcome.

 

[kcobbva]

The rocketpoxy I have had latest through multiple rockets. You'll waste some until you get a feel for it, but it really is worth it.

I use PVC caps on each side of the eBay with the no charges. The motor is just a secondary for the drouge. I don't even drill out the delay. I just get the proper motor with its longest delay and its in place should the BP drogue charge not fire. Pretty sure I have shots of all that in my torrent thread. If you do go with rocketpoxy we can teach you the tricks for very nice fillets. I learned it from everyone out here.

 

[DavidMcCann]

oz for oz, rocketpoxy is cheaper than buying syringes of 5 or 30 minute epoxy. And it's much better. Two pints will go a long way, think multiple rockets.


Weather or not to use a JL release on a 1500 foot flight depends on your field and conditions. I've (accidentally) blown my main chute out at 9,000 feet, and landed close enough not to worry. Most rockets, once broken apart, or having the nose blown off, will tumble. you can control it if need be with a small chute, I typically don't.

This is a graph from my altimeter from a DD flight, which shows the speed is stable under free fall on this rocket. It also leads into your next questions on DD.

It fell under drogue around 74 Mph, and main at 34. This is for about a 6 pound rocket.

This is the GPS track for the same rocket, 4 flights overlaid. the one blue one thats all over blew the main at 9K. the other three dropped well, popped the main at 1000, and you can see where they started to slowly glide back at around 500-600 feet or so once everything got inflated. If you design the recovery system right, opening up at 75-100 mph is a breeze.

DD.... The altimeter will deploy both the apogee charge and the main. this guarantees the rocket breaks in half at apogee, and takes away any need to time the motor delay charge. Or for use with motors that do not have them. Keeping the BP, I've made charges out of centrifuge tubes, glove finger tips, or small aluminum charge cannons. Fireworks ematches are common to use to ignite the charges.

some BP vials, and an ematch-

an av-bay with cannons-

an av-bay insides-

same rocket broken in half after landing in water-

same after main inflated. note payload bay that held main chute in the middle of the chain-

DD rocket laid out after landing-

av-bay without the coupler installed (or any electronics or sled)

ground test in a vacuum chamber with bulbs-
[youtube]qHfL20o2RaU[/youtube]

ground testing-
[youtube]8JjxD48V_e4[/youtube]

[youtube]AVYjfD1uUzE[/youtube]

This gives a basic Idea of what a DD flight looks like riding on the side of a rocket-
[youtube]euJD8tX0Sew[/youtube]


There are a few different altimeters, and even some that include GPS tracking. Some are barometer only, some also have accelerometers.

 

[Caley]

Hi, The "JR Chute Release" was suggested for my "Stretch Blobbo". I am just restarting in the hobby,so I figured like most things, you go back to the familiar stuff, and work your way upward toward the more complex. One thing that kind of troubles me about the "Blobbo" is that they provided an elastic shock cord, and not much length to it. As I understand things, the shock cord should be 3-4 rocket lengths long. The chute should be about two thirds of the way up from the body, and the nose cone attached to the last third of the shock cord. Does anyone have a suggestion for what I should purchase to substitute for the stock elastic one? Maybe you can provide me a link?

Parachutes are something I really need to ask questions about. Where I will fly is on a rock hard dry lake bed. There aren't any soft landing areas. I am guessing I will need a larger parachute for the Torrent, when I do start building it. A 36 inch diameter chute seems a bit small.

 

[Caley]

David, Thanks so much for the time you took to post all of the photos and videos. The chute charge sounded like a gun going off. its going to be at least six months before I get to the Level one situation. I figure that will be how long it takes me to learn enough so that when I do fly the air frame, it has a fair chance of coming back in one piece. But meanwhile, I can be saving the money for all those fancy doo-dads that I will need. Yup, I am very scientific. Everything is a doo-dad or a doo-hickey or a whatchamacallit, and even possibly a thingie. Caley Ann

 

[DavidMcCann]

The chute should be about two thirds of the way up from the body, and the nose cone attached to the last third of the shock cord. Does anyone have a suggestion for what I should purchase to substitute for the stock elastic one? Maybe you can provide me a link?

Use tubular nylon, or...wait for it.... parachute cord in smaller rockets. plain old 550 is great. I tie the chute to the end of the cord, and put the NOSE at the 2/3 mark.

This is why, at the end, the nosecone spins like a top, or flops around and hits things in the tumbles.

This is a good time to note...this is all opinion, and what works for me. Others will hotly contest it...and they will not be wrong. There are many situations, and many solutions. use what works best for you and your situations.

Some places to look at altimeters-
https://www.missileworks.com/store/#!/Avionics-Systems/c/5704272/offset=0&sort=normal

https://www.perfectflite.com/SLCF.html

https://www.marsasystems.com


parachutes-
expensive and amazing- https://fruitychutes.com

affordable and excellent- https://www.the-rocketman.com/chutes.html

Cheap and great- https://topflightrecoveryllc.homestead.com

David, Thanks so much for the time you took to post all of the photos and videos. The chute charge sounded like a gun going off. its going to be at least six months before I get to the Level one situation. I figure that will be how long it takes me to learn enough so that when I do fly the air frame, it has a fair chance of coming back in one piece. But meanwhile, I can be saving the money for all those fancy doo-dads that I will need. Yup, I am very scientific. Everything is a doo-dad or a doo-hickey or a whatchamacallit, and even possibly a thingie. Caley Ann

I take way too many photos and videos....
https://www.flickr.com/photos/31757945@N05/albums
https://www.youtube.com/user/dbmccann9/videos

I did my L1 on a 32oz rocket with an H133BS. single deploy, no electronics. nice and simple. My L2 was at 3300' and I deployed at apogee. You don't have to complicate it with DD, but if you want to, it's simple, affordable, and we'll help you with it. An RRC2 is $45 and can be wired up pretty simply.

 

[Rex R]

let's not forget the term 'gizmo'. braided elastic can be found in the sewing notions Walmart carries it as do fabric stores, even tru-valu hardware. as for sizing chutes hmm Top flight Recovery llc has a nice chart...mostly I use open rocket to simulate various configurations until I find one that works. generally for low power rockets you'll be wanting a descent rate of 12 - 15 fps, mid and high power 15 - 20 fps (under the main chute).
Rex

 

[DavidMcCann]

The Torrent is a fine choice. But if you've got some time to kill.... look at the following companies....

https://www.macperformancerocketry.com
https://www.wildmanrocketry.com/ShowProducts.aspx?Class=463
https://www.madcowrocketry.com
https://www.locprecision.com

 

[Binder Design]

Welcome back and thank you for your 24 years of service! I got into rocketry in the 70's because my dad was in the Air Force. I grew up at Kirtland. You might consider our kits. https://binderdesign.com

 

[NateLowrie]

When you go launch the stretch blobbo, spend some time talking with people and figuring out how they do things and what they recommend. The beauty of the hobby is that there are so many ways to do things and the amount of creativity on here is incredible.

In general, you will need the following in addition to a kit you buy:

1. motor retention - Look at aeropack retainers
2. Possibly rail buttons - Attachment to rails. Plan on flying using 1010 rail.
3. Recovery system - Parachutes and shock cord, possibly attachment eyebolts. Some kits come with the chute. In general ditch the stretch elastic for tubular nylon or kevlar.
4. Epoxy
   1. Dave's already recommended rocketpoxy and it's a good choice.
   2. I use US Composites 635 system. I recommend the 4:1 fast hardener. See https://www.uscomposites.com/epoxy.html for the epoxy. Also, pick up the fillers (https://www.uscomposites.com/fillers.html) Aerosil-Cabosil (fumed silica) and the 3M glass bubbles (microballoons). The quart kit of epoxy and the quart tubs of fillers have lasted now through 5 rockets include my monster level 3 and make really nice fillets.
   3. Stay away from the 5-15min tubes. They are expensive and strength wise there are far better options.
5. Electronics - Not technically necessary. The chute release would be a great product for what you want to do because you can use motor eject for your 1 and 2 cert with the chute release doing dual deploy.
6. Cellulose Wadding (aka "Dog Barf") or nomex blankets to protect the chute and shock cord. A bale of cellulose is roughly $10 at Home Depot and will last you a lifetime. Use it for your small rockets in place of wadding. Larger diameter rockets typically use nomex blankets instead.

Hope this helps.

 

[Bat-mite]

Caley, welcome aboard. These are not your "waning" years. These are the years when you can start to do what you want! :wink:

I only skimmed the other replies, but I have some suggestions.

First, you'll need a motor mount in your rocket that allows you to fly level 1 and level 2 motors, with the right amount of thrust for your rocket's weight.

Second, you'll have a choice of Aerotech, Cesaroni (CTI) or Loki motors. Find out if your club has an on-site vendor, and what they sell. You'll save shipping and HAZMAT fees if you buy on site, but you have to buy what they sell.

Third, absolutely, positively get this book: https://www.amazon.com/dp/1412058104/?tag=skimlinks_replacement-20

Finally, October Sky was based on a book called Rocket Boys, which is a phenomenal read. It is available in the biography section of your local library. I read it and loved it, and went on to read all of the sequels, too. Much better, IMO, than the movie.

 

[NateLowrie]

Finally, October Sky was based on a book called Rocket Boys, which is a phenomenal read. It is available in the biography section of your local library. I read it and loved it, and went on to read all of the sequels, too. Much better, IMO, than the movie.

There was more than one sequel? I absolutely loved it too. Really rich and riveting. On another note, the Audible version of Rocket Boys is awesome if you like audiobooks.

 

[Caley]

Thanks again. There's a lot to digest here.

Yes, for the Level 1 Cert, I plan on keeping the nose cone and payload bay together with buttons. I plan on putting the main in the main airframe body, and using the motor ejection charge to do the deployment work. After I attain my certification, I can then move on to dual deployment practise to make sure I know what I am doing before going for the level 2 cert. The big problem is the cost of each launch. Motors, or even the reloads are pretty expensive, probably limiting me to one or two launches in a weekend for the big rockets. I can always have additional fun with the tiny rockets.

As for rocket engines, I think, after watching a few videos, want to get the permanent casings that you can reload. I hope to get the two casing kit that allows for multiple configurations. I'm going to have to learn what is in a motor, and how it goes together anyway. Why not start early?

I will browse the links as time allows. I will have to make lots of notes both from this thread and all the links provided to get a laundry list of what I might need, where it is found, and the cost. The big deal is the cost. I am retired, but that doesn't mean I am rolling in cash. That's why I mentioned that this will probably take me half a year to get done. Caley Ann

 

[DavidMcCann]

Basically, you have multiple fuel grains, that get loaded into a disposable liner, that get installed into a metal casing. a bulkhead is placed at the top, and a nozzle at the bottom. In snap ring cases (Loki) the nozzle is graphite and reusable. in aerotech and CTI systems, the nozzle is disposable. An ignitor is placed into the core, and slid to the TOP of the motor to get the show started.


This is a reload and 38/120 case for a Loki G69 Spitfire motor-

an Aerotech J510 White Lightning in a 38/1320 case

this shows the parts for two 38mm 2 grain research motors, but the same parts as any commercial snap ring hardware.

This is a Loki G70 Loki Cocktail. It uses two different fuel grains to produce a purple effect flame. (blue and red)

I would recommend getting either an Aerotech 29/240 case and reload adapter system which would allow flying both 29/180 and 29/240 reloads, or a Loki 240 case. Reloads for both do not require hazmat shipping.

This video shows how a good portion of hobby rocket motors burn-

[youtube]SZgxEdajwdE[/youtube]