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Model Rocketry

Started by BTCS1 C/CC, June 29, 2009, 03:50:53 PM

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BTCS1 C/CC

Share your ideas about the cadet model rocketry program. List the names of the Rockets you used and whether the launched were a success or failure.
C/TSgt W

AlphaSigOU

I've built and flown the Estes Mercury Redstone several times. The original was made by Centuri (Estes had a smaller model which was retired after Estes bought Centuri). The fins were originally balsa and made deliberately oversize (by about 25%) for easier flying. The current model uses plastic molded fins, oversize as well. Early Redstone kits used water-slide decals; the current one uses self-adhesive wraps.

The Mercury capsule is correct for Freedom 7 and earlier unmanned or 'chimp-o-naut' flights with the porthole window. If you want to build Grissom's Liberty Bell 7 you'll have to do some major surgery to add the picture window. (And change the 'round' number on the Redstone to read 'MR-3'. Shepard's was MR-7.) The capsule mould is showing its age and needs work to get the sections to fit.

You can fly the Redstone with scale fins but they are small and will cause the model to fly marginally stable unless one adds noseweight to bring the flight model to balance properly on its center of gravity (CG). Even then, it could weathercock in all but calm conditions. Fine details such as antennas and hatches are not included or are printed on the decals.

Scale is very nearly 1/35 (70" body diameter of the full size Redstone / model body tube diameter of 2.04" = 1/34.314 scale).
Lt Col Charles E. (Chuck) Corway, CAP
Gill Robb Wilson Award (#2901 - 2011)
Amelia Earhart Award (#1257 - 1982) - C/Major (retired)
Billy Mitchell Award (#2375 - 1981)
Administrative/Personnel/Professional Development Officer
Nellis Composite Squadron (PCR-NV-069)
KJ6GHO - NAR 45040

arajca

Estes Alpha III (with the balsa fins). Used recommended first flight engine. Moves FAST. Very stable.

Estes SR-71. One of the cadets flew this one and it really flew - about 100' up, it nosed over and flew straight for a good 500 - 600'. Mostly undamaged after landing.

Estes Starship 1 - same story as SR-71. Weird.

AlphaSigOU

You can never go wrong with the Estes Alpha (or its almost ready to fly cousin, the Alpha III). Simple design, excellent performance with a wide range of motors.

Some of the more exotic designs like the SR-71 have been tinkered with to fly stable, but they'll weathercock in the slightest breeze.

Not surprisingly, sounding rockets make the most stable of scale model rockets. Estes makes a higher powered 1/5 scale D-Region Tomahawk that will fly up to an E motor out of the bag. Much of the detail work has already been done for you - molded plastic fins and faceted fin can, as well as a nose cone with screw details. (I should know - I redrew the plans for this famous sounding rocket back in the early 90s during my CAP hiatus working as the plans editor for the NAR's magazine.  ;D)
Lt Col Charles E. (Chuck) Corway, CAP
Gill Robb Wilson Award (#2901 - 2011)
Amelia Earhart Award (#1257 - 1982) - C/Major (retired)
Billy Mitchell Award (#2375 - 1981)
Administrative/Personnel/Professional Development Officer
Nellis Composite Squadron (PCR-NV-069)
KJ6GHO - NAR 45040

jimmydeanno

Quote from: arajca on July 01, 2009, 02:35:01 AM
Estes SR-71. One of the cadets flew this one and it really flew - about 100' up, it nosed over and flew straight for a good 500 - 600'. Mostly undamaged after landing.

This was one of the rockets for our rocketry competitition last month.  Of the 10 that were built, I can't think of a single one that flew correctly.  We were using the A-8 engines, maybe it needs a little more "push" to fly as intended.

If you have ten thousand regulations you destroy all respect for the law. - Winston Churchill

AlphaSigOU

Quote from: jimmydeanno on July 01, 2009, 11:48:00 AM
Quote from: arajca on July 01, 2009, 02:35:01 AM
Estes SR-71. One of the cadets flew this one and it really flew - about 100' up, it nosed over and flew straight for a good 500 - 600'. Mostly undamaged after landing.

This was one of the rockets for our rocketry competitition last month.  Of the 10 that were built, I can't think of a single one that flew correctly.  We were using the A-8 engines, maybe it needs a little more "push" to fly as intended.

A8-3 is a 'popgun' flight for this kit; you're better off flying it with a B6-4 or C6-5
Lt Col Charles E. (Chuck) Corway, CAP
Gill Robb Wilson Award (#2901 - 2011)
Amelia Earhart Award (#1257 - 1982) - C/Major (retired)
Billy Mitchell Award (#2375 - 1981)
Administrative/Personnel/Professional Development Officer
Nellis Composite Squadron (PCR-NV-069)
KJ6GHO - NAR 45040

BTCS1*

Personaly i think an alpha with a B6-4 is ALWAYS reliable! Now C/SSgt. W knows my rocketry sucesses and failures. Such as Misfire XII
C/2d Lt. B. Garelick, CAP

jeancalvinus

I have a highly motivated Cadet who wants to teach the rocketry classes to our cadets before the summer is through. It seems this can only happen if everything is directly supervised by a senior member. Do I read the regs correctly on this? Or am I wrong: he cannot teach at all, it must all be done by a senior member?

Second question is, can the program be completed on 2 consecutive weekends? Or is this rushing things WAAAAY too much? There seems to be a lot of time that needs to go into building these rockets, so it seems 4 weekends would do it. problem is, I want to get as many cadets throuhg this as we can, and a 4 week commitment might be a trecth for most of them.

Any thoughts on this would be appreciated.

jean

arajca

As a CAP activity, it must be supervised by a senior member. That does not mean that a cadet cannot teach the material.

If you're only doing construction at the activity, two weeks is pushing it. If you let the cadet take the rockets home to work on, two weeks should be fine.

DC

Any activity must be supervised by a CAP SM, but there is no reason a cadet cannot teach rocketry or any other relevant subject they are knowledgeable about and/or qualified to teach. In fact if cadets are not doing the majority of the teaching then there is an issue, learning public speaking and how to give both formal and informal instruction are a large part of the leadership training cadets should receive in the Cadet Program.

I have a schedule for a one weekend bivouac that would see 15 cadets through the entire model rocketry program. It's a tight, hectic schedule, but it would get the job done. I'd be happy to email it to you if you would like.

jeancalvinus

Thanks for the info. We are starting this week with the intro and the redstone lecture.

In reviewing this last night I noticed that the second rocket for the titan phase is:

"The cadet can opt to build a scale model of an actual rocket that was a
significant part of aerospace history."

Any low cost ideas on this one?

davidsinn

Quote from: jeancalvinus on August 04, 2009, 01:53:58 PM
Thanks for the info. We are starting this week with the intro and the redstone lecture.

In reviewing this last night I noticed that the second rocket for the titan phase is:

"The cadet can opt to build a scale model of an actual rocket that was a
significant part of aerospace history."

Any low cost ideas on this one?

Depends on your idea of low cost. Dr. Zooch makes wonderful scale models of famous and not so famous rockets for 22-25 dollars. That's about the cheapest that I can find and accounts for all of the fee I need to charge my cadets because my grant doesn't cover everything. I own but have not built the Saturn V and it is a really nice kit. If you have one copy of a kit it wouldn't be impossible to replicate it for little money if you know what you are doing.
Former CAP Captain
David Sinn

jeancalvinus

Thanks for the feedback. I was able to find a cheap version of the Patriot missile for under $10. That covers that stage!

IN THE MEANTIME: any recommendations for where to find heavy duty durable rubber bands? I have looked at Home Depot, Target, Walmart, hardware stores, packaging stores and haven't been able to find any. This is of course for the Goddard rocket (which we will be building this Thursday at the squadron meeting)  we have built some test models and cannot find any thick sturdy rubber bands. We are getting 40 ft of flight (elevation) out of those, but I think we can get more distance out of the heavier rubber bands.

ANY IDEAS?

DC

Quote from: jeancalvinus on August 09, 2009, 05:38:41 PM
Thanks for the feedback. I was able to find a cheap version of the Patriot missile for under $10. That covers that stage!

IN THE MEANTIME: any recommendations for where to find heavy duty durable rubber bands? I have looked at Home Depot, Target, Walmart, hardware stores, packaging stores and haven't been able to find any. This is of course for the Goddard rocket (which we will be building this Thursday at the squadron meeting)  we have built some test models and cannot find any thick sturdy rubber bands. We are getting 40 ft of flight (elevation) out of those, but I think we can get more distance out of the heavier rubber bands.

ANY IDEAS?
The Rocketry Textbook recommends using #64 rubber bands, which you can get just about anywhere, and they work pretty well.

If you haven't been able to find those, or simply do want something bigger, have you tried an office supply store like Staples, Office Max or Office Depot?

Airrace

First of all any activity must be supervised by a Civil Air Patrol (CAP)Senior Member (SM), but there is no reason a cadet cannot teach rocketry. I recomend that a cadet teachs the rocketry class or or any other relevant subject that they are knowledgeable about and/or qualified to teach. This helps build leadership and public speaking and will incourage other cadets to teach other classes as well.

We have in the past scheduled a weekend training class that would see 10 -15 cadets through the entire model rocketry program. They spend a weekend at our local Coast Guard station. The training and building of the rockets take place on Saturday. They build three different rockets and on Sunday they get the chance to see their rockets blast off.  We invite their family and freinds to attend the Sunday blast off event.

Good Luck!

NC Hokie

Quote from: jeancalvinus on August 09, 2009, 05:38:41 PM
Thanks for the feedback. I was able to find a cheap version of the Patriot missile for under $10. That covers that stage!

Where?  Inquiring minds want to know. ;D
NC Hokie, Lt Col, CAP

Graduated Squadron Commander
All Around Good Guy

Spike

May I ask....how long the entire program took (from cover to cover) to complete, and hand out the model rocketry patches??

We are starting the program in a few months and dedicating 1.5-2 hours per month.  Should I spend less time or more time on it??

DC

Quote from: Spike on August 09, 2009, 09:01:09 PM
May I ask....how long the entire program took (from cover to cover) to complete, and hand out the model rocketry patches??

We are starting the program in a few months and dedicating 1.5-2 hours per month.  Should I spend less time or more time on it??
If I were you I'd spend a little more time on it, at that rate it'll probably take you a good 3 - 4 months to finish.

I don't think I could keep my cadets interested for that long...

Rob Sherlin

I don't know how far along you are with rocketry. But, I think you should contact some of the big companies, and tell them you are in CAP and are looking for deals for the cadets. I've been communicating with Apogee, and Estes, vendors on supplies for building rockets from scratch, reusable rocket engines and such. It is cutting down the cost for my plans a lot! I have several big rockets (at least 60", and multi staged), and when the cadets (or anyone) launch those rockets, it get's them further interested. It takes some research and time, but you can put together a good rocketry program that adds to what CAP has, at less cost. I suggest to write them a letter, introduce yourself, and tell them what you are trying to do...They love organizations like CAP, and are willing to help.
To fly freely above the earth is the ultimate dream for me in life.....For I do not wish to wait till I pass to earn my wings.

Rob Sherlin SM, NER-NY-116

Airrace

If your looking to purchase rockets I like the Estes Alpha II or III. This is a easy design and build process and gives the cadets alot of enjoyment when they get to see it fly.

jeancalvinus

WOW! The local hobby shop is pretty much matching the AC Supply price on rockets for our program! That is fantastic! And it isn't like they are a flash in the plan operation either, they are the only dedicated shop in the area and their owner is active in the local RC club.

I am really looking forward to breaking that news to the other senior members. This will both keep the cost low AND help our squadron establish a good relationship with a local supplier. Hopefully, after the cadets get their badges we can have regular launches.

By the way, I have built the goddard rockets (as I mentioned earlier) and have been experimenting with different configurations for the fins. I was able to get one to fly 80'6" (horizontal distance), and after speaking to the hobby shop owner, have some ideas on modifications that I hope will get me over 100.' I think I have launched that thing AT LEAST 100 times. Oh yeah, and I also found a good source for industrial strength rubber bands: that same hobby shop. They use them in wind up airplane models.

Sorry for all the gushing, but I find this rocketry stuff exciting!

Thrashed


Try Fliskits rockets.  They are what Estes used to be in the '60-70's.  Call him, he's very helpful.

http://www.fliskits.com/index.htm

Save the triangle thingy

Thrashed

Here's my 1/2 scale Harpoon missile.  I'm launching it again this weekend on the same motor.  K555

http://picasaweb.google.com/PoconoWargaming/MiscFile#5279474898648295906

Save the triangle thingy

jimmydeanno

^What kind of altitude are you getting out of the K555 with that rocket?  Specs say you get 3.0 seconds of burn time with ~1,600 Ns...

If you have ten thousand regulations you destroy all respect for the law. - Winston Churchill

Thrashed

2046' K555
3294' K950
2943' K670

About 21 lbs at launch.

Save the triangle thingy

jeancalvinus

We just finished the Redstone phase, and the cadets really enjoyed themselves. The fizzy flyers went as high as 12 feet (no joke) and as low as not leaving the launch pad (leaky film canisters). It seems the clear film canisters with the internal cap ring (which is shown in the CAP guide) give the highest flights.

The Goddard rocket was a blast, we had contests on height of flight and on distance. The furthest was around 50 feet, and the highest was about the same (height of course was a pure guess).

Our 2d phase practical will be August 29. I really look forward to it! We will be launching Gnomes, Vikings, and Patriots (all Estes).

Thrashed

Saturday's flight on the K555 went to 2236'.

Save the triangle thingy

jeancalvinus

BTW, has anyone tried building and launching the paper rockets (they are actually card stock) as an alternative to buying rockets? There are several plans online (there is even one specifically for CAP prepared by a Senior Member):

http://rocketry.wordpress.com/ultimate-paper-rocket-guide/

the link for the CAP rocket:

http://nmwg.cap.gov/santafe/Activities/CAPRocket.htm

The obvious advantage here is money: much can be saved. The DISadvantage is TIME: it would take a great deal of it to do this successfully, which would greatly stretch out the training days needed to get the program completed. It would take some dedicated cadets to see this through. There is a design available for every requirement, but it seems the time involved for construction would be high. Any thoughts?

I am trying the "midnight express" from fliskits to see how long it takes to build. Gonna scale it for "A" engines. I will keep ya'll posted.

Spike

Would anyone be able to direct me to the test from NHQ.  I do not see them listed in E-Services.  Must I fill out a Form 8??

davidsinn

Quote from: Spike on August 18, 2009, 07:10:03 PM
Would anyone be able to direct me to the test from NHQ.  I do not see them listed in E-Services.  Must I fill out a Form 8??

You're supposed to send an email to NHQ but the email listed is no good.
Former CAP Captain
David Sinn

Spike


davidsinn

Quote from: Spike on August 18, 2009, 08:28:57 PM
^ Great.........

That being said I just got in the mail today a set of tests by emailing the cadet test email and she forwarded it to the correct department.
Former CAP Captain
David Sinn

helper

Quote from: jeancalvinus on August 18, 2009, 04:59:20 PM
BTW, has anyone tried building and launching the paper rockets ...

Yes, I've helped cadets to built rockets from FedEx envelopes & boxes. The body tubes and nose cones are from the envelopes. FedEx envelopes have a 'coating' that makes them quite durable. The small box is used for the fins. Use ES marking tape for streamers or BestBuy small plastic bags for the parachutes, yellow makes them more visible.

The cadets have been able to make all 3 of the rockets on a Saturday. The build time is faster if the fins are precut. I also make extra body tubes. The scale rocket body tube can be done using card stock with an ink jet printer to add a realistic design.

Here is a 3 'E' engine paper rocket that I put together while watching TV.



Mitchell (pre-number) & Earhart (2144)

jeancalvinus

#33
Helper, thanks for the picture! And I like the low-cost recycle approach of using fedex envelopes!

Question: do you have a problem with "scorching" the inside of the body tube? I have heard that is a issue with paper rockets.

I am trying one to build one as we speak. The nose cones are tricky it seems, but we'll see how the one I am working on now turns out.

jeancalvinus

well we had our phase 2 practical and flew Viking and Patriot rockets. max altitude on the Patriot was 508 ft (single station tracking) on a C6-5, the vikings were too tough to track (overcast conditions and small, white, unpainted rockets).

I would post pictures, but as I do not have 100 posts as of yet, I am unable.

next phase we are trying to get a large enough field to do two stage rockets (I am going to try a three stage Comanche), and will pray of a sunny day so we can track them (gonna try two station tracking, it is far more accurate). The cadets are having a blast (pun intended)!

DC

Quote from: jeancalvinus on September 01, 2009, 02:15:52 AM
well we had our phase 2 practical and flew Viking and Patriot rockets. max altitude on the Patriot was 508 ft (single station tracking) on a C6-5, the vikings were too tough to track (overcast conditions and small, white, unpainted rockets).

I would post pictures, but as I do not have 100 posts as of yet, I am unable.

next phase we are trying to get a large enough field to do two stage rockets (I am going to try a three stage Comanche), and will pray of a sunny day so we can track them (gonna try two station tracking, it is far more accurate). The cadets are having a blast (pun intended)!
You can stick them on an image hosting site like ImageShack and post them without attaching them. 

Thanks for the update on your unit's rocketry program, it sounds like it's been very successful so far!

jeancalvinus

#36
Yesterday was our third phase practical. We launched 3 payloaders (Estes Eggscaliber) and 8 two stage rockets (CC Express). We had probably the most fun we have ever had as a squadron in the time I have been there.

The payloaders did not go very well, only one of three functioned the first time, and of the two remaining, one functioned the second try. The other played lawn dart twice, mostly because (I think) the motor mount is designed to slide around a little depending on the size motor utilized. This allows the motor to slide into the rocket body a bit, and if it goes too far, it creates negative pressure and no thrust (even though the rocket motor is burning). I was on tracking station #1, and both times it went up, it left the launch pad and then immediately began its apogee turn over. It was funny too, both times the parachute deployed about 5 feet from the ground.

We had a few cadets who had to complete two phases of the practical, so we had 3 Gnome rocket launches. Those flew between 122 and 231 feet, and looked quite wimpy compared to the other rockets, but we launched them first so many didn't know the difference.

Next up were the Patriot rockets for a few cadets, and from my vantage point (800' from the launch pad), those were beautiful flights. Our three rockets went 527, 632, and 645 feet respectively. Two had successful parachute deployment, while the third was a lawn dart.

Then came the CC Express rockets. These launches were the most spectacular, with flights of 1439, 1493, 1498, 1543 feet (we had three flights where the rockets flew over the tracking station, so no altitude readings were possible). 5 flights had successful booster stage recovery, with clean parachute deployment. The CC Flies on D motors, and as these were the first D motors we have ever used, we were impressed. Those CC rockets just plain "rocket" off the pad, and really zoom on sustainer motor ignition. The D12-7 provided a very easy to track apogee smoke trail, and is perfectly matched to the CC.

Launch conditions were marginal as to the wind (borderline no-go wind at 9 knots), but the cadets handled the launch duties and did a great job tilting the launch rod into the wind. We were in a field that was about 2500 feet across, and 4 miles long, and as the wind was parallel to the long axis, all rockets were recovered that deployed chute. Tracking conditions were PERFECT, not a cloud in the sky. I did the two station tracking technique, using theodolites on loan from the college. We set our two stations up about 1100 feet part, leveled them up, and then setup the launch site 960 feet from one station and 785 from the other. This meant good accurate data for the Patriots, Eggscalibers, and the Gnomes, but lousy for any two-stage that tracked towards our stations. I read NASA on the topic last night, and they say minimum distance from the launch pad should be at LEAST as far as the highest expected altitude. Lesson learned--which means finding a new field for the next launch as we will be launching the 3 stage Comanche 3 on E-motors (over 2600 feet of altitude) and this field's dimensions won't allow us to setup our track.

I wrote a spreadsheet for data analysis from the tracking stations, and it worked great. Still a few bugs to work out, but overall good data.

The most spectacular flight occurred when a cadet mistakenly loaded 2 D12-7s in the same CC Express. Up went the rocket, and off went the engine, with no 2d stage motor fire. the rocket perfectly arced over at apogee, then the 2d motor fired, with the rocket pointing right at terra firma. That rocket went supersonic in it's gravity assisted flight and SLAMMED into the ground, with the motor still firing. Eager cadets tried to run to the rocket while it was still smoking, but were corralled by a quick acting SM.  We all went over after a minute or two, and the rocket was a total loss, a smoking hole in the ground. :'( :'( :'( The nose cone was buried about 8 inches deep (and to add insult to injury, in a cow pie). We all hummed an impromptu "TAPS", much to the chagrin of the cadet who launched it. She did take it all in stride though. Another note: those CC Express Rockets are a bit sturdy--one had no chute and lawn darted from 1500 feet of altitude, but was able to fly again.

The scenery was great. We launched in a mountainous valley (in a rancher's field), and it was just beautiful. The cadets handled the launch duties, and safety considerations were properly observed (the cadet commander was more safety conscious than the SM were). We probably laughed more than we ever have at any single event. If you haven't done a rocketry program, do it. It will be a real joy for your cadets. :clap: :clap: :clap:

DC

Sounds like you guys have a great program running. Would you mind emailing me the spreadsheet you cooked up? I'd like to use something like that of and when we manage to secure funding to do our program...


Thrashed


Save the triangle thingy

Rob Sherlin

#39
I don't hold "NAR" or "Tripolli"  high power certification, but I had the experience working on, and launching high power rockets with a buddy of mine when I lived in California. It kind of seems to me that CAP's rocketry program is very fundamental, and deals more with history than actual knowledge of rockets. How many know how to read the engine numbers to decide what type of engine to use?..How many have designed and built rockets from scratch with a just a variety of tubes and balsa sheets?
Right now, I am currently working on a Fliskits "Tres" (3 cluster), but it's being modified to become a 2-stage rocket by modifying the engine mounts to take "D" class engines (upper stage will carry "C"), and will carry a 2 event timer chip as it's payload, with 2 seperate recovery deployments for each stage.
I want to get the Cadets into more of designing and building (therefore learning more than just building a kit by instructions), so they will learn more, have fun, and want to go further.
To fly freely above the earth is the ultimate dream for me in life.....For I do not wish to wait till I pass to earn my wings.

Rob Sherlin SM, NER-NY-116