1st time with 2 stages

[Velocity Aerospace]

I'm working on another big project that will be posted farther down the line, but I wanted to get familiar with the concept of staging, so I built this little guy just as a quick build to see how it will work. There aren't many similarities between the two projects beyond the fact that they're both 2 stage, but I've gotten backlash for not following the "normal" progression of rocketry, and pushing my knowledge (in a safe manner), so just to ensure I know what I'm doing, I'm starting small.


It has a 24mm mount for the booster, and an 18mm mount for the sustained. The total length is 29". Sometime soon, I'm planning on flying it at my local park and see what it can do. After I paint it of course

 

[David_Stack]

Suggestion... Your fins will have more strength if you align the grain in the balsa to run parallel to the leading edge (as it appears you did with the booster fins). The fins on your upper/sustainer stage have the grain running in a less-than-optimal direction.

 

[Velocity Aerospace]

Suggestion... Your fins will have more strength if you align the grain in the balsa to run parallel to the leading edge (as it appears you did with the booster fins). The fins on your upper/sustainer stage have the grain running in a less-than-optimal direction.

Yeah... you're right. I've been working with mostly fiberglass recently, so it hadn't crossed my mind. I'm thinking of papering my fins to try to rectify the problem. The reason it happened is I tried to cut all the fins from the same stock, so some of the grains mismatch

 

[smstachwick]

How is your stability on that? The fin area looks a little on the small side, especially with the sustainer.

Otherwise I think it’s fine. Maybe consider flying the sustainer on its own first.

 

[Velocity Aerospace]

How is your stability on that? The fin area looks a little on the small side, especially with the sustainer.

Otherwise I think it’s fine. Maybe consider flying the sustainer on its own first.

I was planning on flying it by itself first. I know the fins are a bit small, but this isn't one of my big planned out projects. I just threw it together to get an idea, and to move to a small scale to just have fun again. It may not be the most stable by itself, but with the booster, when the sustainer lights, it should be going well fast enough to create sufficient drag. I'm going to be very cautious with it, and take precautions.

 

[Raythain]

How is your stability on that? The fin area looks a little on the small side, especially with the sustainer.

Otherwise I think it’s fine. Maybe consider flying the sustainer on its own first.

Fin area looks a little small, but it still looks significantly more stable than an Estes Hi-Flier. Might need a little nose weight, but mind sim doesn’t show anything exceptionally egregious.

Should be easy to throw in OR quickly to check.

 

[Velocity Aerospace]

Fin area looks a little small, but it still looks significantly more stable than an Estes Hi-Flier. Might need a little nose weight, but mind sim doesn’t show anything exceptionally egregious.

Should be easy to throw in OR quickly to check.

I've already added putty to the nose cone to bring the cg forward. I'm also adding little finletts and papering them for strength

 

[Bruiser]

"but I've gotten backlash for not following the "normal" progression of rocketry"

You know, the thing is that safety needs to come first. You don't just throw stuff together and give it a go. That's just not safe. It only takes one incident to have an effect on every rocketeer in your area.

People have mentioned fin area. You added a little more. Why not use Open Rocket and see if the rocket is safe to launch? It's free and it's not hard to learn.

The fin grain on the sustainer is going the wrong way. You aren't the first and you won't be the last. So you paper the fin to strengthen it. Jury is out whether that will help enough. Many threads about it, not as many as glue threads, but still plenty.

I realize that rockets don't need to be pretty but the fins aren't the same size, you didn't even bother to take sandpaper to the leading edge to at least smooth them.

The whole thing is very amateurish. We were all there once but may I suggest a mentor? Oh, and Open Rocket? Rocketry is not something you want to learn the hard way because doing so could mean someone gets hurt.

Not trying to be mean. I just want everyone to enjoy the sport and no one to get hurt. That's it; I've said my piece and will go away now.

-Bob

 

[Velocity Aerospace]

"but I've gotten backlash for not following the "normal" progression of rocketry"

You know, the thing is that safety needs to come first. You don't just throw stuff together and give it a go. That's just not safe. It only takes one incident to have an effect on every rocketeer in your area.

People have mentioned fin area. You added a little more. Why not use Open Rocket and see if the rocket is safe to launch? It's free and it's not hard to learn.

The fin grain on the sustainer is going the wrong way. You aren't the first and you won't be the last. So you paper the fin to strengthen it. Jury is out whether that will help enough. Many threads about it, not as many as glue threads, but still plenty.

I realize that rockets don't need to be pretty but the fins aren't the same size, you didn't even bother to take sandpaper to the leading edge to at least smooth them.

The whole thing is very amateurish. We were all there once but may I suggest a mentor? Oh, and Open Rocket? Rocketry is not something you want to learn the hard way because doing so could mean someone gets hurt.

Not trying to be mean. I just want everyone to enjoy the sport and no one to get hurt. That's it; I've said my piece and will go away now.

-Bob

I am safe with my rockets. Ive been doing this long enough to know where the line is. The fins were unfinished, and so did look rough. I have since cleaned them up and just haven't put updated photos on here yet. Yes, the grain was the wrong way, but this is a low power rocket that won't experience that much dynamic loading. There are models built way worse that fly beautifully. I will correct for next time, but I don't think it's an issue for a rocket this small.

Now, what I meant with my comment was there seems to be this "correct" way to progress in rocketry. Yes, I started in low power, moved up to mid power, and got my level 1 HPR cert just this past January. So yes, there is a road map, but I'm not going to do things the way everyone else does.

I have open rocket, and rocksim, and I use them frequently. This is a proof of concept. I've built many rockets by just throwing stuff together, and it works great. I don't deny that those programs are great, but I don't think they need to be used every time.

I do things safe. Different, but safe.

 

[Velocity Aerospace]

Paont job is done, and it's ready for its first flight. Hopefully sometime this week, I can take it out and see what it can do

 

[BABAR]

I like the design!

Fin grain direction isn’t perfect, but main thing IMO is it isn’t parallel to body tube, so I think you should be good.

Finlets on the sustainer will help some, adding them to BOOSTER would add more. Oops, you just painted it. Ah well.

Papering doesn’t fix grain direction. I speak from experience. I still think you will be okay.

Let’s talk motor choices. For first flight, I think a C11-0 would be great for the booster. This will keep staging easily in site.

For sustainer, start small. A8-5 if you can find it, otherwise A8-3 or even better A10-3T with adapter. You do want to fly it again, this is more likely to stay in the field. Also, if flight is not nominal, the less motor you have the better.

Hope you get two straight trails and a short walk!

 

[Velocity Aerospace]

I like the design!

Fin grain direction isn’t perfect, but main thing IMO is it isn’t parallel to body tube, so I think you should be good.

Finlets on the sustainer will help some, adding them to BOOSTER would add more. Oops, you just painted it. Ah well.

Papering doesn’t fix grain direction. I speak from experience. I still think you will be okay.

Let’s talk motor choices. For first flight, I think a C11-0 would be great for the booster. This will keep staging easily in site.

For sustainer, start small. A8-5 if you can find it, otherwise A8-3 or even better A10-3T with adapter. You do want to fly it again, this is more likely to stay in the field. Also, if flight is not nominal, the less motor you have the better.

Hope you get two straight trails and a short walk!

I have some A8-3s, but the smallest 24mm motors I have are D12-0. I'll probably pick some smaller ones up before I launch. I did put a slightly smaller parachute on it to get it down faster. I had considered doing a streamer, but my drop tests from my roof seemed to do just fine

 

[smstachwick]

I have some A8-3s, but the smallest 24mm motors I have are D12-0. I'll probably pick some smaller ones up before I launch. I did put a slightly smaller parachute on it to get it down faster. I had considered doing a streamer, but my drop tests from my roof seemed to do just fine

I agree wholeheartedly with the endorsement of the C11s. They’re fantastic little motors, good for keeping hot rods under control. Take the time to have them shipped out to you, or if you have a launch day vendor, see if they can get some for you. There is no deadline.

Unproven stability in a two-stager can be deadly. If the stack is unstable but the sustainer is stable, it might thrash around, stage in an unsafe direction, and then make a stable flight in that unsafe direction. I’ve made that mistake before and it was absolutely the single scariest thing I’ve ever seen on a rocket range. I don’t recommend putting yourself at that kind of risk. If you do, I recommend down-powering your rocket to mitigate that risk. Less installed total impulse and less weight in the aft section will help you here.

It’s kind of a no-brainer, really. You can set yourself up for improved safety and success for only the ~ $12 you’d spend on a two-pack of motors and an hour of fooling around with OR. Why wouldn’t you?

 

[OverTheTop]

I went non-traditional with my first two-stage flight. O3400-M2020. Peaked at M2.14 on the way to 37500'. 15+ second staging delay, with tilt inhibits.

Yes, was done with safety considered at every step along the way.

 

[Velocity Aerospace]

I went non-traditional with my first two-stage flight. O3400-M2020. Peaked at M2.14 on the way to 37500'. 15+ second staging delay, with tilt inhibits.

Yes, was done with safety considered at every step along the way.

My other project will be fairly similar. Not anywhere near the same power, but it will be a level 1 rocket. I'm looking at getting a telemini for the sustainer and an easymax for the booster (I think it has tilt limits. I'm getting one that does, and I'll check) everything looks great in open rocket. Now I just have to save up

 

[Velocity Aerospace]

I agree wholeheartedly with the endorsement of the C11s. They’re fantastic little motors, good for keeping hot rods under control. Take the time to have them shipped out to you, or if you have a launch day vendor, see if they can get some for you.

I have some hobby stores around that I should be able to get some at, and I'm going to try to get my hands on them

 

[beeblebrox]

Remember though... Two stage with black powder is easy, not so with large rockets with composite motors... You cannot (Easily) direct stage them. (Yes... AeroTech had some 24 and 29mm booster stage motors back in the day but there were too many issues...) I recently flew an Estes BT-50 kit two stage with an AeroTech D10-0 staged to an Estes C6-7 - It was lost... (AT doesn't make D10-0, it was an EX motor modified from an AeroTech Reject, so don't ask AT for them, they don't exist.)
My best Two stage attempt was staged using a pressure switch inside the booster bulkhead to fire second stage igniter.
K400 - 1800NS, K250-20 In a Laser Loc at Black Rock II. Tracked altitude of Upper Burnout, 17,500 ft. (Theoretical Burnout altitude from Gary Rosenfield's software was 17,250) Peak track was lost but based on theoretical burnout, peak was in excess of 42,500ft. (The theoretical peak altitude.) I inadvertently flew over the base line, oooops. No one told me where the trackers were.... Recovery failed due due the later discovery that delay material burned at a much slower rate at higher altitude.

 

[Velocity Aerospace]

Remember though... Two stage with black powder is easy, not so with large rockets with composite motors... You cannot (Easily) direct stage them. (Yes... AeroTech had some 24 and 29mm booster stage motors back in the day but there were too many issues...)

Yeah. I'm not planning on directly staging with the motor. That's why I'm looking at the easymega with the 6 Pyro channels, so I can set it up to fire the motor from the computer and have redundancy with it. There will be more about it when I start the build thread for it

 

[BABAR]

My other project will be fairly similar. Not anywhere near the same power, but it will be a level 1 rocket. I'm looking at getting a telemini for the sustainer and an easymax for the booster (I think it has tilt limits. I'm getting one that does, and I'll check) everything looks great in open rocket. Now I just have to save up

Sounds cool. So you will get your L1 on the sustainer with a single stage flight, then add the booster?

 

[Velocity Aerospace]

Sounds cool. So you will get your L1 on the sustainer with a single stage flight, then add the booster?

I already have my L1, this is just a project I've wanted to do for a bit

Thread 'Genesis II scratch build' https://www.rocketryforum.com/threads/genesis-ii-scratch-build.180353/

 

[user 38430]

It would've been fine without the fin extensions, but looks very Cool either way. One thing I've always enjoyed is when something someone claims "Can't possibly fly" and goes up straight like an arrow. It's usually met with silence or "you got Lucky", even after the 5th succesful Launch.

 

[bobbyg23]

Send it! Looks great.

 

[Velocity Aerospace]

Send it! Looks great.

I have a busy week coming up, but if I can get time, I definitely will