Model Rocketry Discussion Thread

[goldenpeach]

I launched a few rockets model.

But it was only those small kits for young children you can get everywhere, and don't go high at all.

[B787_300]

this^

read above I explained some common ways to doing it

[Spanier]

Is this still considered as model rocket?

http://www.warr.de/raketentechnik/stern

[B787_300]

ah that might be a bit more than model... but eh, it works

my current project is a F9v1.1 that will be something like 7 feet tall

[Neil1993]

I have built quite a few. In fact, I have 2 waiting in the wings right now (they both have yet to launch).

this is one that's meant to carry a 10 lbs payload :

[B787_300]

nice... you using G10 Fiberglass for the fins? and the airframe looks like carbon fiber and the nose is wood with a metal cap?

[Neil1993]

nice... you using G10 Fiberglass for the fins? and the airframe looks like carbon fiber and the nose is wood with a metal cap?

Almost all correct! The nose is balsa which has been laminated with fiberglass and capped with a plastic tip. We're probably going to replace it with a hollow fiberglass nose.

[B787_300]

sigh so close..., yall compete in any rocket comps? that looks more like a school rocket for something like IREC

[Neil1993]

sigh so close..., yall compete in any rocket comps? that looks more like a school rocket for something like IREC

You must be psychic. It is indeed for IREC

[Budgie]

I'm Level 1!

1k (probably), perfect recovery and landed 10ft from the pad. I did NOT expect it to go that well:

Javascript is disabled. View full album

I also do papercraft rocketry, with free models from a number of sites, blown up to 1:48

[B787_300]

so Budgie, what kit is that, what motor, and do you have a plotter to print out the models?

[Budgie]

Its a Madcow Super DX3 Payloader, an H123 and no serious electronics. An arduino that was meant to measure altitude that didn't work correctly.

And nope, just a regular old printer and some 100lb card stock, and the models made on this site:

http://www.axmpaperspacescalemodels.com

[BagelRabbit]

My god. This thread is alive again? Hooray!

So, I've been flying L1 for a while... mostly H motors, because our club doesn't have a wavier for any more than that. Some of you guys might remember when I got a Video Wednesday for launching Jeb and a GoPro. Here's a more recent Jeb and GoPro launch, as the original one wasn't nearly cinematic-ey enough!

(Here's the Kerbal that the rocket was carrying, up close. It was made of clay, weighs about three ounces, and has been epoxied beyond belief. Sorry for the large image!)

I currently hold the record (I think) for Highest Kerbal-Facsimile-Carrying Rocket Launch, at 2,891 feet. Same rocket, same Kerbal figurine, I140-14W DMS from Aerotech. Man, that thing took off fast. Good fun, all around. Also, I probably should have drilled the delay, as the thing was well on its way down before the parachute deployed. Fortunately, no zippers, and no damage!

OH, AND BY THE WAY:

I think I deserve some love for this... thing.

It's a foam-core-board soccer field with LEGO minifigures on it. And it has a big styrofoam "soccer ball" on the top. And I flew it on a G78 Mojave Green motor.

It spun as it went up, far into the clear blue yonder. It was a perfectly stable boost, contrary to the generally observed laws of physics. (Base drag is my friend.) It topped out at about 40 feet, because it was basically a parachute with a motor stuck to the back of it. And then it gently descended to Earth, breaking off a couple of the minifigures on landing but otherwise undamaged. It was a glorious triumph of science over sanity.

I'm probably never going to fly it again, though.

Anyways, if you have any questions about putting cameras on rockets (or flying sports fields), I can answer them.

[B787_300]

/me looks at the soccer ball and shakes head...

only 40 ft on a G.... launch it on an I

[BagelRabbit]

/me looks at the soccer ball and shakes head...

only 40 ft on a G.... launch it on an I

See, I was going to launch it on an H195, but then I decided that it wasn't a good idea. I think the thing would shred. Besides, I'm thinking that this thing would be borderline unstable in even a slight wind, and I don't want to take any chances strapping a bigger motor on there.

This is hardly rocket science, though.

[B787_300]

on side note anyone know of a good Dual Deployment Altimeter, preferably accelerometer based that is relatively cheap?

[Exosphere]

I know this might not be completely on topic, but I'd rather not start an entirely new thread for this.

I've recently gotten back into model rocketry, and have decided to start doing some basic amateur/EX rocketry stuff. Luckily, I found a pretty good site that gives instructions for how to construct a relatively small PVC rocket motor:

http://www.nakka-rocketry.net/pvcmot4.html

I've also found some basic information about the construction of a static test stand, and have already hooked up a load cell to provide me with a thrust curve. So far, I have but one major problem:

Where should I test the motor?

I live in the Bay Area, so I'm not exactly in a remote area, and neither my friends nor I own any kind of rural property. This would seem to limit my options with regards to doing static tests, never mind actual launches (I haven't even really thought about how I could get the required permits to launch rockets, as it would seem like it would be very difficult to do so in my area). I know lots of people launch/test model rockets in parks and the like, but I'm not entirely sure I could do the same with an "experimental" rocket. Furthermore, I've heard that a lot of parks require permits to launch even model rockets. Also, I'm a bit uncomfortable conducting tests in areas where there are likely to be other people, due to the risk that would be posed if the rocket CATOs (I'm planning to install a relatively sturdy barrier around the test stand to catch any shrapnel if the casing ruptures, but I still don't want to take any chances).

Does anyone have any advice on how I could go about finding a place to conduct static tests?

Edited September 20, 2014 by Exosphere

[B787_300]

yes i do... My school has a rocket propellant team and we do test firings. if is is a smaller motor (in the H-I range) we do it behind out lab. Now we clear out a 50ft radius circle of cars and people plus the motor is surrounded by cinderblocks on 4 of 6 sides, the ground being one of the remaining 2 and open is the last (where the flame comes out) so that way even if we have a explosion the casing is directed out in one direction which we can point. For our larger motors we take them to the local landfill to test. we get permission from them first.

[Exosphere]

yes i do... My school has a rocket propellant team and we do test firings. if is is a smaller motor (in the H-I range) we do it behind out lab. Now we clear out a 50ft radius circle of cars and people plus the motor is surrounded by cinderblocks on 4 of 6 sides, the ground being one of the remaining 2 and open is the last (where the flame comes out) so that way even if we have a explosion the casing is directed out in one direction which we can point. For our larger motors we take them to the local landfill to test. we get permission from them first.

Out of curiosity, how difficult was it to get permission? There are a few landfills and similar locations I could get to, but I'm not entirely sure how they'd react to getting a random phone call from someone that wanted to fire home-made rocket motors on their property.

[B787_300]

i have no idea, i was not involved in it...

also as long as it is small, just make a temporary bunker out of cinderblocks and do it in your or a friend's backyard if you think it is big enough

[Exosphere]

i have no idea, i was not involved in it...

also as long as it is small, just make a temporary bunker out of cinderblocks and do it in your or a friend's backyard if you think it is big enough

I would if I could -- I'm currently in an apartment, and everyone I know in the area either lives in an apartment or a dorm (I just recently moved in from out of state, so I don't know that many people yet). The closest thing I have to a "backyard" is a parking garage under the apartment building, and I get the impression that my neighbors would be a bit unhappy if I tested my motors there.

Thanks for the advice about trying landfills though -- I guess I'll try that option out.

[mardlamock]

I know this might not be completely on topic, but I'd rather not start an entirely new thread for this.

I've recently gotten back into model rocketry, and have decided to start doing some basic amateur/EX rocketry stuff. Luckily, I found a pretty good site that gives instructions for how to construct a relatively small PVC rocket motor:

http://www.nakka-rocketry.net/pvcmot4.html

I've also found some basic information about the construction of a static test stand, and have already hooked up a load cell to provide me with a thrust curve. So far, I have but one major problem:

Where should I test the motor?

I live in the Bay Area, so I'm not exactly in a remote area, and neither my friends nor I own any kind of rural property. This would seem to limit my options with regards to doing static tests, never mind actual launches (I haven't even really thought about how I could get the required permits to launch rockets, as it would seem like it would be very difficult to do so in my area). I know lots of people launch/test model rockets in parks and the like, but I'm not entirely sure I could do the same with an "experimental" rocket. Furthermore, I've heard that a lot of parks require permits to launch even model rockets. Also, I'm a bit uncomfortable conducting tests in areas where there are likely to be other people, due to the risk that would be posed if the rocket CATOs (I'm planning to install a relatively sturdy barrier around the test stand to catch any shrapnel if the casing ruptures, but I still don't want to take any chances).

Does anyone have any advice on how I could go about finding a place to conduct static tests?

I live in a large city as well and I do my tests on my building´s rooftop, if you keep your designs simple and not too ridiculous then the chances of a CATO are very low. I ve had my motors fail 6 feet from me and nothing happen, so long as you know the estimated pressure is not going to burst the pvc you are alright.

[B787_300]

ya my schools motors have blown casings before... so not exactly small time stuff

[Armchair Rocket Scientist]

on side note anyone know of a good Dual Deployment Altimeter, preferably accelerometer based that is relatively cheap?

These three are good choices: all are DD-capable, fairly cheap and popular, and will fit inside most rockets. However, all of these are barometric-based.

http://www.adeptrocketry.com/ADEPT22go.htm

http://www.missileworks.com/store/#!/RRC3-Sport-Altimeter/p/25239688/category=5760485

http://www.apogeerockets.com/Electronics_Payloads/Altimeters/PerfectFlite_StratoLogger_Altimeter?cPath=52_192&zenid=ljs9o3ncrk6vrkjarpls2ibii0

This one is extremely compact, but a bit pricier.

http://www.apogeerockets.com/Electronics_Payloads/Dual-Deployment/EasyMini?zenid=ljs9o3ncrk6vrkjarpls2ibii0

This one is very expensive at over $300, BUT it has integrated GPS tracking.

http://www.apogeerockets.com/Electronics_Payloads/Altimeters/TeleMetrum?cPath=52_192&

Finally, there's the Raven. This altimeter is absolutely tiny including the battery, and is very capable, including an accelerometer and four pyro outputs. This means that among other things it can be used to ignite the motor in a rocket's upper stage and still control the deployment. It also allows the user to set up backup deployment charges. However, it is fairly expensive.

Unfortunately, I don't know of any accelerometer-based altimeters that are inexpensive. However, it's possible you could build one yourself with an Arduino or similar product. However, it would most likely not be as compact as any of the commercial options, so that's only a good idea if you have a relatively large rocket that will fit it.

http://www.featherweightaltimeters.com/The_Raven.php

[B787_300]

By the way here is my current design for my Level 2 cert from OpenRocket https://www.dropbox.com/s/9vsdi414vwggs1u/Level2CertIdea.ork?dl=0 feel free to download and tell me if i have overlooked something pretty dumb