Need Help Exceeding Mach 1

Charles_McG said:

Anything wrong with going smaller? An Apogee Aspire with an Aerotech H115 DMS? That stays within L1.

Well, other than the 50G accereration and the difficulty of recovery?

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Try to find or clone a Vaughan Brothers Extreme 24 and use a CTI F240. Use a chrome Mylar streamer for recovery. Because of the impulse you do need to have a High Power certified flier to load and launch but it will meet the parameters. Cheapest way to achieve the objective, too

Fontastic said:

We figured we would need to go with a smaller diameter, and after research we knew we needed carbon fiber or fiberglass or reinforcements by either of the two. We have never played with carbon fiber nor fiberglass, but have experience with epoxies.

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nope. I've taken a completely stock Loc Vulconate well past mach - it's just paper....fins are plywood, au natural with some butt ugly Hunter Green paint.
The only special thing was that I was holding it when challenged to break mach with it....took a while to find it.

cbrarick said:

nope. I've taken a completely stock Loc Vulconate well past mach - it's just paper....fins are plywood, au natural with some butt ugly Hunter Green paint.
The only special thing was that I was holding it when challenged to break mach with it....took a while to find it.

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How fast did you take that? I've got a stock Vulcanite I'd love to slide a J510W into....

Charles_McG,

The Apogee Aspire will hit Mach 1 with the right motor, but I have heard it is a fire and forget rocket. If you fire it, forget about finding it. One guy in my club had one and we never saw it again after it left the pad.

Here's my 2 cents from the inexperienced optimism of the Shade Tree Rocket Lab

I was playing in OpenRocket with 24mm min diameter ideas and you may be able to achieve your goal on an F72 or G55 single use motor. I used a balsa transition from the BT-50 to a BT-20, tweaked the fin design, adjusted ballast and played with the length (about 15 in.) and both sim at just over 1700 fps max velocity. Are there challenges to building this so that it doesn't re-kit its self and is still light enough to achieve your goal? Yes, but the initial max velocity numbers leave a pretty good margin for reinforcing the airframe. This design used a balsa nose cone and transition, standard body tubes and plywood fins. As a bonus, on a G55, it sims to 5400 feet. If you can squeeze your altimeter into a BT-50, a payload section doesn't hurt performance too much. One major down side to this though, this could easily end up as a YOLO rocket.

I would post my basic concept but TRF is being a pain right now.

I built my own 'launch it and loose it' Aspire inspired rocket last year. I put an 8"X96" ( I think) Mylar birthday banner in it as a streamer and shoved a G80 in. I was surprised at how visible it was.

Of course, my boy's L1-jr cert flight came up during the descent and I stopped tracking mine to watch his. His flight went great. I never even attempted recovery of mine.

Launch It and Loose It II will be 24mm min diameter for this G55 single use motor I picked up.

And regarding the F240 - over 80N average thrust, so it still counts as L1 HPR.

dave carver said:

...Because of the impulse you do need to have a High Power certified flier to load and launch...

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Charles_McG said:

And regarding the F240 - over 80N average thrust, so it still counts as L1 HPR.

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...must....resist...comment...

dave carver said:

...must....resist...comment...

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Sorry Dave, I first read that as 'don't need'. Just sloppy reading on my part. Didn't mean to be redundant.

Charles_McG said:

Sorry Dave, I first read that as 'don't need'. Just sloppy reading on my part. Didn't mean to be redundant.

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It's ok, isn't redundancy a part of rocketry...at least for the big guys?

I've worked with SystemsGO staff and a few schools in the Houston area. A couple of restrictions that I remember from last year. SystemsGo is tied closely to NASA and one of NASA's requirements is that ALL ROCKETS must launch with commercial HYBRID motors. NASA feels that AP motors are not safe for students.

I believe the hybrid motor reload options are fairly restrictive. If I remember correctly, most teams were going with a K700 54mm reload on a minimum diameter 54mm bird. Many of these were either prebuilt or scratch built Carbon Fiber birds.

This is not an easy challenge for students who have VERY LITTLE HPR experience.

I am the prefect for Tripoli Houston. We launch at Hearne Texas on the 2nd Saturday of each month. www.tripolihouston.com We have offered to assist ANY SystemsGO team but so far only a few have contacted us and none of the teams have come to a launch. And that's a shame. Their crash to success rate on launch day each year is pretty ugly... Lots of lawn darts and lost rockets...

A comment directly to the young rocketeers on this team: If you just want to go through the process, build and launch the rocket to your best ability, roll the dice on the launch and finally get your grade, then you're on the right track. However, if you're EXCITED about rocketry, interested in tapping into a HUGE WEALTH of engineering experience, watch some really large rockets launch (J to M class) and truly experience high power rocketry, making the trip to Hearne or to the folks in Louisiana would be a valuable investment. Learn from the old guys who've already made all of the mistakes so you can avoid them.

Sincerely,

Andy Berger
Prefect, Tripoli Houston
L3, TRA# 14032

I've worked with SystemsGO staff and a few schools in the Houston area. A couple of restrictions that I remember from last year. SystemsGo is tied closely to NASA and one of NASA's requirements is that ALL ROCKETS must launch with commercial HYBRID motors. NASA feels that AP motors are not safe for students.

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Hybrids are safer than APCP? That just doesn't make sense to me. Also, in the Student Launch program, NASA requires use of commercial APCP motors, with an L2 mentor to handle motors and ejection charges for middle and high school teams. So at least some arms of NASA want to use APCP. The students still design and build the rocket airframes and experiments that go inside, as well as selecting the motor.

I really like the challenge issued by a HS rocketry club teacher--break Mach on a Class 1 rocket. That is a good test of skill, but probably doable on cardboard body tubes without going to exotic airframes.

So if Andy's right (and I suspect he is), then I think it would be valuable to watch this video:

[video=youtube;P5JxXka50Gw]https://www.youtube.com/watch?v=P5JxXka50Gw[/video]

It's a fun video to watch (with hybrids), but the abridged version is that they're professional amateurs, they were VERY well financed, they got help from someone who truly knows his stuff, and they STILL completely failed in retrieving a rocket in workable condition. In that whole show the only parachute I saw fully deployed and slowing a rocket on the way down was with an Estes Riptide (which is a Ready To Fly rocket - they didn't build it).

Simply put, the 'up' is the easy part. Flying a few rockets will help with your odds of success.

I'm interested in Mach 1.
Not too worried about the design, motor selection, or strength of the rocket.

Given the height a relatively small rocket will reach, I am interested in recovery strategies.

Advice welcomed.

SO.

I use an Eggfinder GPS and and deployment altimeter in 24 mm CF designs with a Mylar streamer. In your case I would drop the altimeter to save weight and use motor eject. You will lose altitude because of too short of a delay but you said you wanted speed. An Altus Micro peak could record the flight.

Fontastic, seems I'm in a similar scenario as you. Senior in high school, with a bit of rocketry experience. I'm currently looking to apply for a level 2 high power certification, and want to do a bit more, break the sound barrier. Your project seems to be similar, I'm thinking it would be cool to trade notes on this topic. I'm still trying to get this project started though.

MP42 said:

Fontastic, seems I'm in a similar scenario as you. Senior in high school, with a bit of rocketry experience. I'm currently looking to apply for a level 2 high power certification, and want to do a bit more, break the sound barrier. Your project seems to be similar, I'm thinking it would be cool to trade notes on this topic. I'm still trying to get this project started though.

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L2 and supersonic are not too tough, when you are devoted to your cause and build with care. My Nuke Pro Max did both on a J290, and technically was my first approved high power build. It used nothing but Bob Smith 5m epoxy.

Most importantly, take your time and enjoy the process!

It looks like during the Obreth program they are expected to purchase the materials of the rocket, not fabricate them.
The challenge to the students is to "figure it out" as a class credit.

my advice is that if Crazy Jim H is willing to mentor you, grab it. He's one of the best rocket guys around, and truly is a "been there done that" type of guy. Not sure you could give him a task in rocketry he hasn't done repeatedly and successfully.

you can take unglassed LOC paper tubing well past mach without needing to be fiberglassed. The recent advent of thin walled fiberglass gives you another option that doesn't add a lot of weight but adds significant durability. Talk nice to Jimbo and he could get Wildman to do some custom slots for your design using thin wall fiberglass.

good luck, keep us posted!

Thanks! When you built your Nuke Max Pro, were there any special modifications you made? That's the kit I was looking at working with. Some of the stuff I found while researching recommended applying fiberglass, and other modifications. These included lengthening the motor mount, and adding a third centering ring. Is there anything specific you would recommend?

watermelonman said:

L2 and supersonic are not too tough, when you are devoted to your cause and build with care. My Nuke Pro Max did both on a J290, and technically was my first approved high power build. It used nothing but Bob Smith 5m epoxy.

Most importantly, take your time and enjoy the process!

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Thanks! When you built your Nuke Max Pro, were there any special modifications you made? That's the kit I was looking at working with. Some of the stuff I found while researching recommended applying fiberglass, and other modifications. These included lengthening the motor mount, and adding a third centering ring. Is there anything specific you would recommend?

Hehehe my nuke pro max was built with aeropoxy. Stood up to the J600. Took a long time to get it back.....not sure how fast it went.
Ask Grouch how fast his went....took a while to walk the several miles to get it back.He broke mach by a significant margin.

MP42 said:

Thanks! When you built your Nuke Max Pro, were there any special modifications you made? That's the kit I was looking at working with. Some of the stuff I found while researching recommended applying fiberglass, and other modifications. These included lengthening the motor mount, and adding a third centering ring. Is there anything specific you would recommend?

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Nothing essential. I drilled a hole in the payload bulkhead for wiring, put an altimeter into the payload bay, and made the nose cone attached but removable with a screw through the shoulder. This was so it can release a bound parachute at apogee, then fire a cable cutter at lower altitude, to get dual deployment and closer landings. It will fly fine without any of that, though you might have to walk farther to get it back! You will probably want a tracker for these altitudes and speeds, too.

After a tough landing or two I fiberglassed it, though the initial big flight was definitely supersonic and definitely no fiberglass. I hear people have problems with longer motors, but 38mm5G was not an issue at all, for both fitment and material strength.