Who else here is into model rocketry?

[artao]

Heya!

I'm one of those people known as a BAR -Born Again Rocketeer .. As in, I enjoyed model rockets as a kid, and have re-discovered them as an adult. Except these days I tend to design my own rockets rather than build kits.

Model rocketry has come a long long way. There's a lot of model rocket motors these days that use APCP (Ammonium Perchlorate Composite Propellant) instead of the old blackpowder-motors. Totally space-age too, as APCP is what space agencies actually use in solid rocket engines.

Also, there's numerous software options for rocket design available, some are even OSS! (see http://openrocket.sourceforge.net/ )

It's a pretty inexpensive hobby too, as long as you stay nearer the lower end of the available power range.

Anyone can purchase up to G powered engines, where each letter can contain up to twice the power of the previous letter; with A being up to 2.5 N-s (even down to 1/4 A or smaller) and G then being 80 - 160 N-s !!

And then it goes further, up to P IRRC, but for those you need to be certified, and there's 3 levels of certification. Anyhow, rockets above G become rapidly more expensive and begin requiring more advanced construction such as fiberglass and suchnot. They also require FAA clearance with a submitted and approved flight plan.

Typical model rockets of G and lower are generally cardboard tubing, with thin plywood and balsa for fins and internal components. MUCH less expensive.

Anyhow, just curious who else out there is into it.

That is all.

[angusmcbeth]

Never tried rocketry, but I have to say, it does look fun (plenty of stuff on youtube). I also thought it would be a bit expensive when you added stuff like GPS for recovery, altimeters etc..

Have you taken any onboard footage Artao? Show us some photos of your designs!!

Suggestion: Make a real rocket painted KSP style!

(I would be interested in photos of any small cheap designs you might have, suitable for kids)

Edited May 19, 2013 by angusmcbeth

[Corw]

North Korea is taking notes.

[artao]

No onboard footage .. yet. .. Atho I HAVE designed a rocket to launch a webcam. Just haven't built it yet. And now that I have a new webcam, I can remove the case from the old one to save space and weight, and thus re-design my cam-rocket for that. .. In Progress.

Also lacking photos. I've lost the majority of my rockets so far LOL .. it does take some skill in determining proper launch angle and azimuth given prevailing winds to get a successful recovery. .. And, I can't say I've done "a lot" of it over the past few years that I got back into it.

Altimeters can actually be pretty reasonably priced. Simple ones for less than $50. GPS for recovery is rare, and yes expensive. Loud beepers are common and cheap tho. You can also get more advance flight computers for staging motors (required for APCP) and drogue/main chute deployment.

You don't HAVE to spend much money, but you can also pretty much spend as much as you want or can.

Real rocket painted KSP style? Hmm. Might do, might do.

Current projects include same-scale (~1:110) semi-detailed models of Vostok I and Mercury I, and a rather large rocket designed to launch very slow and not go up very high, as well as some new launchers for rocket gliders as well as some new rocket gliders. .. Maybe even a helicopter recovery rocket. .. Also a cluster-engine rocket, but for that I need to build a proper cluster-ignition system.

There's plenty to do in model rocketry without spending a ton of money.

[Carthaginian]

I did this as a kid too, and am also rediscovering it along with my father as he shows some of the youth at church how much fun it can be.

We actually completely scratch-built many successful rockets using materials as simple as: strong cardboard, garbage bags, coke bottles, plastic caps from spray-paint cans, and PVC pipe. Our biggest one was almost 4 feet tall, had a 32 gallon trash bag as a parachute and a 3 liter cola bottle as a nose cap... it used D12 engines and survived a dozen launches or more before being retired.

I love building them- so far I haven't built any mew ones, but I'd love to get back into it, money permitting.

Edited May 19, 2013 by Carthaginian

[loppnessmonsta]

I did this as a kid, though not long after I got into it, my family moved from our farm to a city house, so it became impractical.

[loiske]

I am planning to start this, seems to be a lot of fun and you can basically do everything by yourself, including the engines!

edit: thanks for that openrocket -link, seems to be quite useful program

Edited May 19, 2013 by loiske

[artao]

@loiske -- re: making your own engines. That is potentially VERY dangerous, and moves from model rocketry to amateur rocketry. AFAIK you don't need any special licensing to make your own engines, BUT you sure as hell better know what you're doing, and have a safe place to do it.

However! You can go halfway and get reloadable engine systems. These consist of a set of casings and bulheads you buy that are re-useable, and then you buy motor reloads which consist of tubular lengths of APCP that you insert into said casings, along with high-temp plastic nozzles that come with each engine kit. As such, you aren't creating your own engines from scratch, BUT you get the joy and thrill (and risks) of assembling the motors.

I have yet to buy myself a motor-casing set, but it IS in my plans.

..EDIT..

one could, of course, also make one's own nozzles out of metal given proper equipment, or even 3D printers. making nozzles really really would be rocket science, as the nozzle shape greatly affects thrust and efficiency. Of course, it also would be riskier as you risk possibly not allowing the internal pressure to escape fast enough (or too fast) causing engine blowouts (i.e. explosion, tho APCP is designed to NOT be explosive) or not enough thrust for a stable flight.

However, I do believe this would again delve into the realm of amateur rocketry, not model rocketry.

..EDIT EDIT..

you can also take another step further in actual model rocketry by using hybrid motors, which use cannisters of NO2 to increase the thrust of APCP engines. Those are rather pricey, but certainly add more to the whole thrill on the rocket engine side of model rocketry.

Edited May 19, 2013 by artao

[Itsdavyjones]

Still need to repair some of my rockets, and I only just started getting an income, so now it can be affordable for me.

[Panichio]

I'd like to give it a go at some point. That program looks like fun.

[Rockhem]

It's a good hobby, I would reccomend one of the estes rockets E2X for beginners. Only probably a hour of assembly to give you a taste of building. They can also fly in small areas.

biggest commercial motor I have seen has 2.5 tons of thrust! The standard engines have about 2 pounds to 3 pounds of thrust. ( don't quote me, may vary)

[jdmgto]

I love model rocketry and I've been getting my kids into it. I'm not wild about the new "kits" that give you a rocket already built.

[legoheli]

I am so jealous of you model rocketeers. It's illegal here in Denmark without direct authorization from the Air Force (like Copenhagen Suborbitals has and has to cooperate with the Navy/Air Force to launch anything), and almost any rocket fuel is illegal to own. Or well, the fuel is fine, the oxidizer isn't.

[Vostok]

I'm launching my newest model soon. I might post updates here if people would like.

I'm launching homemade rockets with homemade rocket fuel engines. Since I can't be bothered doing the necessary calculations, they usually explode or burn or do nothing at all. Currently I'm refurbishing the last one, which only burned half its fuel, and then stopped, due to a bad lot of fuel I cooked.

Here are the first two launches:

EDIT: Launch #4 Scheduled for tomorrow.

Edited May 19, 2013 by Vostok

[Rockhem]

What do you mean fuel and oxidzer? Model rocket engines don't have seperate fuel and oxidzer in them.

[legoheli]

Any solid rocket fuel substance (that's any fun) is illegal. You can only own KNO3 here if you have a chemical license.

And homebuilt liquid rockets are impossible because you can't own LOX.

[tom1499]

I'm 14 so cant really be a born again rocketeer. Where I live we cant get rocket motors (Kids here don’t have any thoughts of rockets or explosives outside of those cheap firecracker things you get) and DHL would kill you if it had this sort of stuff in thier packages. But water rocketry is still kinda fun, and there always homemade solid fuels.

[Sir Nahme]

Wehn I was a kid we used to use the store bought solid fuel engines but once I moved into the city yeah it became impractical, really wish I had the time these days to skip town and fire a few missiles at the clouds

[Brotoro]

I've been a model rocketeer since I was 14. In fact, no kerbals for me right now because I have to go run our monthly club launch.

[Lechimp89]

I would quite like to get into it, but I don't think my garden is big enough, and there isn't really anywhere else I can do it

[NeoMorph]

Some of those water powered rockets are mind blowing.

But these ones are better but really need a better ASAS lol

Edited May 19, 2013 by NeoMorph

[artao]

Having seen home-brew propellent brought up a couple times, I gotta say again that that can be VERY dangerous. You really really must know what you're doing, and have a safe place to do it. All it takes is one mess up, and there go your eyes, or your hands, or your life. Mixing up rocket propellent properly is no trivial matter. Mass-produced rocket motors have had hundreds of thousands if not millions of dollars invested in their development, with a focus on reliability and safety. It is in fact CHEAPER to buy commercial motors than to try to make your own.

Also, when someone inevitably has an unintended explosion or other incident, the media makes no distinction between amateur rocketry and model rocketry. There's been more than enough regulations limiting safe and dependable model rocketry due to incidents involving amateur rocketry.

I'll get off my soapbox about that for now, but it IS a big issue in the model rocket community frankly. Something that is strongly emphasized. Buy motors, don't make them.

Edited May 19, 2013 by artao

[Canopus]

I wish i could someday build one of these:

[artao]

Nice vid there NeoMorph!

That would be high-power rocketry indeed. That rocket probably cost a couple grand to build and launch once, and prolly around $500 per launch thereafter. It would also require FAA clearance, but for events like that (clubs often have group events) a flight window clearance can cover the entire day's worth of launch activity for everyone involved.

I don't have the link handy, but one of the most impressive high-power rockets I've seen (not in person, never seen one in person) was a scale model of the Soviet N1 moon launch vehicle. Staged correctly and all. It was HUGE and quite impressive.

Lemme see if I can find it on the YouTuber quick here ...

...

ahh yes, here it is .. there's a longer version somewhere that shows bulding and flight-prep scenes as well, but I'm not seeing that just now.

[artao]

Here's a VERY interesting video (albeit not the one I was looking for, which is even more impressive and I'll post it when I find it).

This video shows what happens when a rocket's fins can't handle the stress of exceeding Mach 1. This is, again, a high-power rocket.

I know there's a way to post YouTuber links thst start at a specific time, but I'm not sure how. SO! Jump forward in this vid to 1:27 to see what happens.

That is not photoshopped etc etc. The fins really really DO bend and twist like that.

Crazy! eh?

..

..

..

EDIT

HA HA!~! Found the one I really wanted to post. In this one the fins don't "explode" off the of rocket. It comes back down with fins intact. However, the fins would not be safe for another flight because tiny tiny cracks had formed throughout it's structure. .. I can't find it, but there's yet ANOTHER vid where the rocket builder-owner shows how easily the fins could shatter after that flight.

Edited May 19, 2013 by artao