My first scratch build and first multistage rocket - Janus I

A couple weeks ago, I got a bug to try a two-stage rocket, but I didn't have a kit. I'd also been playing with OpenRocket, toying with the idea of finally trying to design and build my own rocket.

I decided to go for both at once. When I first started building rocket kits, I thought I'd never be able to design and build my own. But I've learned a lot in the last few months, and felt I could do it.

I came up with Janus I (I already have a Janus IB and Janus II half designed). A 20-inch tall, 1.64 inch diameter rocket.

I was in a hurry to finish by Thursday, so I decided I'd call this a "prototype" so I wouldn't mind coming up with a quickie paint scheme - and wouldn't feel too bad with a launch failure.

Here's an OpenRocket still of the original design:



Here's the built rocket:



Not crazy about the paint scheme, but I somehow managed to make it really shiny - not sure what I did different here from on different builds.

I used the free parachute I got from JonRocket.com with my last purchase.

Last night (Thursday, October 30), we launched it. I was nervous. But it performed beautifully. Estes C6-0; C6-5 motors:

[video=youtube_share;Qu8BZL-zLsI]https://youtu.be/Qu8BZL-zLsI[/video]

I feel a real sense of accomplishment having done this, since I've only been doing rocketry for little over three months, and I wanted to share it with you.

Nice work! Always nice to see a project like that come together and fly sucessfully. Congratulations!

Thanks for sharing it.

rbelknap said:

Nice work! Always nice to see a project like that come together and fly sucessfully. Congratulations!

Thanks for sharing it.

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Thank you! I was pretty proud to accomplish this!

Nice build!
3 months in ,ahhh?
I have to say, "I'm real impressed"
Look forward to seeing what you come up with in your future designs.

Thank you! I was pretty proud to accomplish this! And you should. It's a great feeling. Scratch building is the bomb.

Very nice! Is this gap staged (space between the motors)?

Awesome!:clap: Congrats on the Successful Launch.

SCrocketfan said:

Very nice! Is this gap staged (space between the motors)?

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Nope. I wanted to do... whatever it's called when the motors touch - contact staged? - first. I'd seen those work, so I wanted to do something I knew how to do before trying a gap staged rocket.

Although, after designing this, halfway through the build, I did start designing a gap-staged model.

In The Handbook of Model Rocketry, pressure relief holes in the booster are mentioned for gap-staged rockets. Is that pretty standard? Would you recommend them?

Scotty Dog said:

Nice build!
3 months in ,ahhh?
I have to say, "I'm real impressed"
Look forward to seeing what you come up with in your future designs.

Thank you! I was pretty proud to accomplish this! And you should. It's a great feeling. Scratch building is the bomb.

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Thank you! I've become rather obsessed, and read a lot on the subject, tried a lot of techniques out. I feel like I've learned a lot in very little time.

This weekend, I'm raising funds for a local theater, and my incentive for donors was that I'd design and build them a rocket. I figure that's a good way to get more scratch build practice in, and it'll make me think come up with new designs. And I've raised $300. Not a ton, but far more than I've raised for this event before, and more than most (if not all) the other actors.

lcorinth said:

Nope. I wanted to do... whatever it's called when the motors touch - contact staged? - first. I'd seen those work, so I wanted to do something I knew how to do before trying a gap staged rocket.

Although, after designing this, halfway through the build, I did start designing a gap-staged model.

In The Handbook of Model Rocketry, pressure relief holes in the booster are mentioned for gap-staged rockets. Is that pretty standard? Would you recommend them?

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Did you tape the motors? That's how I've flown my Estes Mongoose before, and they seem to always stage reliably.

I would recommend holes for gap staging. My 2-stage mega mozzie (see attached) has a few inches between stages and two small holes on the booster coupler, and it staged fine (I've only flown it once 2 stage, so I can't confirm it will always work but I think so).

SCrocketfan said:

Did you tape the motors? That's how I've flown my Estes Mongoose before, and they seem to always stage reliably.

I would recommend holes for gap staging. My 2-stage mega mozzie (see attached) has a few inches between stages and two small holes on the booster coupler, and it staged fine (I've only flown it once 2 stage, so I can't confirm it will always work but I think so).

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I did tape the motors. With the design, I should have had more space for tape than I ended up with, but in construction, I put the centering rings slightly off the mark. This meant I had to trim about 1/4 inch - or maybe 1/8 - from the coupler, and I had a little less room for the tape, but the adjustments worked, and I had exactly enough room for the width of the Scotch tape I had on hand.

First rocket - two, really - I saw as a two-stager was my one rocket friend Chad's Estes Taser Twin (he flew two of these, and though they flew beautifully, they were both lost. He loses a lot of rockets...), and that rocket had taped motors. It was the first time either of us had seen that, and it seemed so strange to us that we weren't sure we were doing it right at first.

But once I started reading more (both The Handbook of Model Rocketry and the new release Make: Rockets: Down-to-Earth Rocket Science), I realized this is totally normal stuff.

I'm really pleased that my first one worked as well as it did. My minor construction flaws didn't seem to hamper performance, and I learned from them. My one regret for this video is that my girlfriend got distracted by the booster falling and didn't track the sustainer further up its trajectory with the camera - but she's been pretty supportive, and this is probably one of my better videos. She even donated to my theater fundraiser, asking me to make her two rockets - one named for each of her two nephews. So, I think she's on board for this thing of mine.

Nice job, you have every reason to brag a little. I'm not clear on why your friend lost his Tasers. Lost sight in the air ? Unrecovered 'cause you overflew the field ?

IMO vents in the booster of gap staged models is cheap insurance and can't hurt.

Sounds to me like your "videographer" is a keeper !

That is a nice design and build. Well done!

samb said:

Nice job, you have every reason to brag a little. I'm not clear on why your friend lost his Tasers. Lost sight in the air ? Unrecovered 'cause you overflew the field ?

IMO vents in the booster of gap staged models is cheap insurance and can't hurt.

Sounds to me like your "videographer" is a keeper !

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We have a pretty big field, but he has a tendency to lose them, nonetheless. The first one had such a beautiful flight, and kept going and going... and kind of disappeared. He said he was pretty sure it was in orbit. But we didn't see it fall at all.

The second one fell beyond a barbed wire fence into some really tall scrub grass. We had thought it was farmland, but I found out it was actually part of the county fairgrounds - I nearly went to look for it when I launched at the fairgrounds a few weeks later, but the grass was super tall and buggy, and I figured it would have been ruined by heavy rains anyway. Dude just has no luck - he's lost about 20 rockets in the last three months - that's like $400 bucks or more of rockets!

I think I'll keep the videographer.

Ok gotcha. He just has to learn to fly the field; sometimes that means easing off the gas (lower impulse motor), reefing shroudlines, or changing out parachutes for streamers. That Taser in particular or any minimum diameter stager is gonna get up there in a hurry. Wait, what am I saying, gimme a C6-0/C6-7 for that puppy !