Poor Man's' Watch Forum

More Off Topic or Non-Watch related Post Thanksgiving hijinks. Many Post contains Picture(s) s >

Posted By: Ricky Lee McBroom
Date: Sunday, 26 November 2006, at 3:33 p.m.

In keeping with the Self-made Watch Stuff! theme of the weekend, I decided to teach The Twins all about rockets.

It worked smooth, except for the part where Haley disobeyed an order from the RSO (Range Safety Officer, namely me Laughing out loud! ), got a stern reprimand, and threw a tantrum. I am not happy! Girls will be girls. Smiley

Anyway, a carefully planned launch by a Master Rocketeer goes like this. First, you pick a low-powered (and, oh, cheap and disposable Rolling on the floor laughing my a.. off! ) model;

Don't tell your baby grand-daughter, though. Laughing out loud!

These were old competition models (A Streamer Duration), very light (6.5 to 6.8 grams), and reached perhaps 150 meters on the vintage Centuri 1/4A4-3M engines we used. They fly great!

We hung the first one in a tree, but gauged the wind perfectly on flight two..

..she recovered it successfully, and so Junior Rocketeer Hannah Curtis was certified into the Fraternity Of Old Model Rocketeers.

You then move to higher-powered rockets. This one is designed for a C (10 Nsec), though we used a B instead, an Estes B4-4.

Click to enlarge.

This one flew great, too, reaching perhaps 300 meters. We could have recovered it, but chose not too, since it fell on the property of a grumpy neighbor.

The next we painted first. It's a max-perormance competition design, too, this one being D/E (24MM engines) Parachute and Streamer Duration. Estes airframe, hand-sanded airfoiled hard balsa fine, etc. After I recycled the 2 meters of Kevlar thread it sported from it's days in the ring (hey, this stuff is like US 50-cents/foot!), and glued on a launch lug, it was ready to go...

Click to enlarge.

...No pics, unfortunately. Grabbing a lift-off pic of a full-E comp rocket is nearly impossible. Especially when it's packing a full load, as this one was. Laughing out loud! Rolling on the floor laughing my a.. off! We used an Aerotech E10-8, a full 40 Nsec engine - 10 Nsec average thrust over a 4 seconds span.

This is, of course, a scholarly way of saying that this thing really cooked. Smiley It punched through to 2,000+ meters by flame-out, and coasted to perhaps 3,300 meters before deploying a 15-foot streamer. The hang time (timed with my trusty CASIO Twincept was an impressive 4-1/2 minutes before it fell behind the treeline, perhaps a mile downrange.

Later, after the wind calmed, we broke out a Bigger Rocket;

Click to enlarge.

This is was a Q & D engine waster that I'd assembled from spare parts years ago, and had never flown. Haley put a My Little Pony sticker on it, and we christined it 'The Pony'. The flight profile, alas, was.. errr, well, it was less than optimal. Smiley

It did a 'core sample'. I am not happy! I used an A5-2 engine, and it should've been a full B. Ah well, I make my rockets strong, and after I surgically removed the damaged 50 MM of airframe, it was ready to fly again.

Much better on Estes D-12 power!

Our day ended on a sad note, however, as this one hung in a tree. I am not happy! Ah well! Smiley Still lotsa fun! Laughing out loud!

-Ricky

Messages In This Thread

More Off Topic or Non-Watch related Post Thanksgiving hijinks. Many Post contains Picture(s) s > (views: 208)
Ricky Lee McBroom -- Sunday, 26 November 2006, at 3:33 p.m.
Here is my largest one Post contains Picture(s) (views: 12)
Bill J. -- Monday, 27 November 2006, at 2:52 a.m.
I built rockets as a kid, probably starting at 10 years old or so. Then I got more interested in cars and other things. Then one time while surfing the net I discovered that the hobby is still going strong. As a kid we used the Estes engines, mostly A and B engines, before they even came out with a C. Then I discovered FSI and they had C and D engines. What I discovered recently is that Aerotech has engines much bigger than that. In the photo is my largest rocket, built for my level I certification flight. It flies on 38mm H and I size reloadable engines.
Bill J
A brother rocketeer! Hey Bill! >> (views: 1)
Ricky Lee McBroom -- Monday, 27 November 2006, at 9:34 a.m.

} I built rockets as a kid, probably
} starting at 10 years old or so. Then I
} got more interested in cars and other
} things. Then..I discovered that the
} hobby is still going strong.

That's almost exactly the way it went down for me, too. Indeed, 'tis the classic 'Born Again Rocketeer' profile. Smiley

} As a kid we used the Estes engines,
} mostly A and B engines, before they
} even came out with a C.

Whoa! You must have started a few years before me. Smiley Or maybe I stuck with it longer, as Estes was making the D12 before I abandoned rockets the first time around.

} In the photo is my largest rocket..

Sweet! Looks like a LOC Precision kit?

} ..built for my level I certification flight.

Being something of a contrarian, I passed my Level I cert flight with an Estes kit. Laughing out loud! The first to ever do so, I'm pretty sure.. heck, maybe still the only to ever do so. 'twas modified somewhat from stock, mind you, but still an Estes kit at heart.

} ..38mm H and I size reloadable engines.

What a revolution those were! By the time reloadable engines were released my son was a teenager, and our active involvement in HPR was winding down. But I did invest in a full set, simply because they were so much more cost-effective than disposable engines. My Inner Scotsman couldn't resist. Laughing out loud! The only one I've got left is an RMS-54/852 (54 MM, a 'light J' of 850 Nsec total impulse).

-Ricky
and a launch photo Post contains Picture(s) (views: 10)
Bill J. -- Monday, 27 November 2006, at 2:56 a.m.

Someone else took this photo and I don't remember if the launch was with the H or I engine.

One day I also built a rocket to break the sound barrier. I bought an Aerotech F72, which is a lot of power for a 24mm diameter engine. I built a minimum diameter rocket, and added some fiberglass to try to keep the fins on. Computer simulations predicted Mach 1.4, but I'm not sure they are accurate above Mach 1.0. Once the engine ignited, the rocket was never seen again, it moved off very fast.

Liftoff
And a very nice launch photo 'tis! Post contains Picture(s) >>
Ricky Lee McBroom -- Monday, 27 November 2006, at 9:47 a.m.

} Someone else took this
} photo..H or I engine.

Great photo! Good rocket lift-off shots are tough. Nearly as tough as watch photography. Smiley

My most similar rocket is a North Coast kit, the Phantom. Here's a liftoff shot on Aerotech J125 power:

Click to enlarge.

} I also built a rocket to
} break the sound barrier.

Not that tough to do, of course, except..

} ..added some fiberglass to
} try to keep the fins on.

..for that part. Laughing out loud! Keeping surface-mounted fins attached to a supersonic model is not a trivial task!

The rocket in my initial post (the one with the multi-colored hippy paint job Laughing out loud! ) used surface-mount fins. And with a full E motor, that's definitely pushing it.

BTW, your addition of fiberglass reinforcement is a sound idea. I used a similar technique to surface mount fins on a 54MM airframe;



I used a layer of epoxy-soaked carbon fiber mat, wrapped completely around the airframe, and 'L-brackets' of the same construction along the roots of the fins. There were naysayers who said this would not survice, but it worked just fine on the Aerotech I32 flight. I believe it could have survived a full J, but never got the chance to prove it...

Click to enlarge.

} Once the engine ignited, the rocket was
} never seen again, it moved off very fast.

Next time put 'bout 1/4 cup of Zerox toner, folded loosely in recovery tissue, right on top of the parachute. Wear gloves, it's messy! Laughing out loud! Rolling on the floor laughing my a.. off!

The results are well worth it, though. That big black 'puff' of of Zerox toner can be spotted from literally miles away! Some advocate less messy alternatives, like powdered chalk. And it's OK, I use it sometimes. But for a max-Q flight, where you've got to spot a small model at 5K+ meters, NOTHING is better than Zerox toner. Accept no substitutes! Rolling on the floor laughing my a.. off!

-Ricky

Thumbs Up for this Watch Awesome Thumbs Up for this Watch (views: 7)
hedgesjr -- Sunday, 26 November 2006, at 5:46 p.m.
Re: You made me remember the halcyon days of youth >>>> (views: 1)
Ricky Lee McBroom -- Monday, 27 November 2006, at 10:49 a.m.

Whoa! Don't think I've ever made anyone "..remember the halcyon days of youth" before!

Sorry I totally overlooked that this was not a message the first time through! I am not happy!

} I'm quite sure my daughter would
} enjoy some rocket launching too.

See?! Kids are the perfect excuse to launch rockets again.. Smiley Laughing out loud! Rolling on the floor laughing my a.. off!

} My favorite engine was the C6-7.

Ah! A High-Power man at heart! Smiley

} It could cause you to lose lighter,
} smaller rockets fast.

Yup. But with a 7-second delay, 'tis really a top-stage motor. As a single-stager, it should only be used with very light models!

} You made me remember the halcyon days of youth,
} launching rockets with my best friend ...

Glad to be of service. Smiley

Tellya what.. Send me an Mail me! w/ your return adress, and I'll send you and your daughter a rocket. My Xmas present to y'all! Smiley

-Ricky

Way cool pics and it looks like a lot of fun for all. Thumbs Up for this Watch Post contains no message text (views: 4)
chrise2469 -- Sunday, 26 November 2006, at 5:40 p.m.
Thats awesome, I grew up launching rockets with my brother! (views: 12)
Jeffc -- Sunday, 26 November 2006, at 5:39 p.m.

It was such great fun building them and launching them!
Thumbs Up for this Watch My days of rocket science were short-lived as a teenager. Smiley (views: 17)
Chris L -- Sunday, 26 November 2006, at 5:18 p.m.

I remember in particular the last time I launched some rockets. I had acquired an Estes scissor-wing glider kit and spent almost a month assembling and painting the rocket with silver paint, and trimmed in red. On it's maiden flight I loaded it with a C6-5 (it was a heavy rocket) and tried to anticipate the wind. I had too much angle on the launch tower, and of course a C6-3 would have been a better choice for the engine. The rocket went ballistic, and the deployment stage didn't fire until the rocket had fallen to 10 feet off the ground with the nose aimed directly at the ground. The engine assembly puffed out the back with a perfect chute deployment, the glider's wings snapped into glide configuration just a fraction of a second before craterring into the ground. Rolling on the floor laughing my a.. off! Rolling on the floor laughing my a.. off! Rolling on the floor laughing my a.. off!

I actually believe that the deployment stage drove the rocket harder into the ground. Wink

Great Story! Thumbs Up for this Watch BTW, I've got.. > (views: 14)
Ricky Lee McBroom -- Sunday, 26 November 2006, at 5:47 p.m.

A mint, vintage, sealed Scissor Wing kit out in a box in the garage.. Interested? Smiley

I'll make ya a heck of a deal! Maybe a watch-for-rocket swap? Laughing out loud! Rolling on the floor laughing my a.. off!

-Ricky

Rolling on the floor laughing my a.. off! I don't think I could live through that heartbreak again. Rolling on the floor laughing my a.. off! Post contains no message text (views: 7)
Chris L -- Sunday, 26 November 2006, at 5:54 p.m.
OK, remove the heartbreak factor. I took.. Post contains Picture(s) >> (views: 28)
Ricky Lee McBroom -- Sunday, 26 November 2006, at 6:50 p.m.
..pictures of these a while back, with an eye to putting them on Found on the Bay!

Click to enlarge.

Pre-built, ready to fly! And great workmanship, if I do say so meself! Smiley I started with 3/16" light balsa, and those wings have the most beautiful hand-sanded airfoil you'll ever see! Laughing out loud!

Come on, trade me for a watch! I'm determined!

Rolling on the floor laughing my a.. off! Rolling on the floor laughing my a.. off! Rolling on the floor laughing my a.. off! Rolling on the floor laughing my a.. off! Rolling on the floor laughing my a.. off! Rolling on the floor laughing my a.. off! Rolling on the floor laughing my a.. off! Rolling on the floor laughing my a.. off! Rolling on the floor laughing my a.. off! Rolling on the floor laughing my a.. off! Rolling on the floor laughing my a.. off! Rolling on the floor laughing my a.. off! Rolling on the floor laughing my a.. off! Rolling on the floor laughing my a.. off! Rolling on the floor laughing my a.. off! Rolling on the floor laughing my a.. off! Rolling on the floor laughing my a.. off! Rolling on the floor laughing my a.. off!

-Ricky

Cool Post contains Picture(s)s! Post contains no message text (views: 25)
John N -- Sunday, 26 November 2006, at 4:37 p.m.
I always wanted to try that as a kid (still do!) maybe my kids will want to give it a shot Wink Post contains no message text (views: 6)
Stef G -- Sunday, 26 November 2006, at 4:28 p.m.
Re: I always wanted to try that as a kid (still do!).. >> Post contains Link (views: 13)
Ricky Lee McBroom -- Sunday, 26 November 2006, at 4:41 p.m.

Go for it! Thumbs Up for this Watch

My son and I were really into if for 4 or 5 years. I mean totally immersed in it, National competitions and all.

I can't imagine a better way to spend time with the kids. My son learned more, and we grew closer together, sitting for long hours at the workbench building those models than any other activity we did as he was growing up.

Oh, and he's a 14 Tango (Patriot Missile system) in the US Army now, so I guess it made an impact on his career choice. Laughing out loud!

-Ricky

More 'bout Ricky's Rockets

Cool website! I just need someplace big enough to launch...nothing really around here, just woods. Post contains no message text (views: 6)
Stef G -- Sunday, 26 November 2006, at 5:43 p.m.
I was fortunate to live nearby a couple of schools with very large athletic fields when I was a kid. (views: 8)
Chris L -- Sunday, 26 November 2006, at 5:51 p.m.
My local high school has a HUGE athletic field behind it with 5 tennis courts, a full-sized football practice field, cross-country field, and simple 5-hole golf course. More than enough space for a launch complex
I always had a big open field at a local park! Post contains no message text (views: 3)
Jeffc -- Sunday, 26 November 2006, at 5:59 p.m.
Thank you! RLM. Your girls are beautiful. Its a blessing to have twins. Smiley Post contains no message text (views: 8)
Larry -- Sunday, 26 November 2006, at 3:47 p.m.
Thumbs Up for this Watch Very cool, Ricky! I used to build and fly those. Big fun! But; stay away from the trees! I am not happy! Smiley Post contains no message text (views: 7)
Greg H. -- Sunday, 26 November 2006, at 3:43 p.m.
Re: Big fun! >> (views: 13)
Ricky Lee McBroom -- Sunday, 26 November 2006, at 5:28 p.m.
Ever seen a big 'un fly?


The full story.

Until you've witnessed a K motor launch, you just don't understand.. Smiley

BTw, the motors progress exponentially:

D = 20 Nsec

E = 40 Nsec

F = 80 Nsec

G = 160 Nsec

H = 320 Nsec

I = 640 Nsec

J = 1280 Nsec

K = 2560 Nsec

Estes (blackpowder) engines have always cut off at the D size, Centuri used to make E's. Some mavericks like FSI and Rocketflite used to make blackpowder G's.

Great fun, but all my engines above D nowadays are modern 'composite' fuel motors. The fuel itself is polybutadine rubber. Smiley It has an embedded crystallized oxygenator, amonium perchlorate. Very safe, the exact stuff the Shuttle solids use. The biggest I've flown was an Aerotech reloadable, a K1100-16. That's a 'light K' of some 1850 Nsec...

-Ricky

That is really impressive Ricky!!! (views: 11)
Jeffc -- Sunday, 26 November 2006, at 5:51 p.m.
I enjoyed all your rocket pages! I had a few of those "basic" models! Thats too cool! You defintely took it farther than I ever did! AWESOME stuff!
Re: I enjoyed all your rocket pages! >> Post contains Link (views: 4)
Ricky Lee McBroom -- Sunday, 26 November 2006, at 8:16 p.m.

Thanks, Jeff!

This was The Ultimate Rocket, in case you missed it. NOT the K-powered scale behemoth that is technically my 'most powerful launch'.


The H-Squared®

This was my semi-serious attempt at the I-Altitude record (and I actually hoped to break the J record, too. If you're gonna dream, dream big. Laughing out loud! )

The key here, is that it's a 2-stage rocket. All the I-Altitude records on the books at the time used a single-stage, full 640 Nsec motor. These are 54MM in diameter, and demand a 100MM diameter airframe, if they are to survive.

By going to a 29MM full-H, and staging them, I could design around a 42MM airframe, and still have room for the through-the-wall fin construction that is crucial for a supersonic model.

Now, there was one snag. The only true full-H in 29MM is the Aerotech H125 (IOW a 2.56 burn time. 320 total Nsec/125 average Nsec=2.56). Fine for stage 1, where the idea is to clear the thick air quickly. But not so good for stage-2, where the idea is to accelerate less briskly through the thin air, but for a long time.

The optimal motor profile for the top stage, I determined through sims, was an H45. At 29MM, this would result in an engine length of 850+ MM. Barely possible from an airframe design standpoint, but made extremely problematic by the heat-resistance threshold of filament-wound composite case material.

I had a friend who made custom motors, and we determined that by going to a 2-layer casing, something like an 820 MM long H60 was theoretically possible. Alas, that never happened and, while not the record-breaker I'd envisaged, my max flight of H125-to-H125 was tracked to 7,000+ meters. And hit a conservative Mach 2. Rolling on the floor laughing my a.. off!

Click to enlarge.

By contrast, the perfect flight profile** for the H125-to-H60 combo, according to the sims, was 16,000+ meters. That is over 50 thousand feet! Not exactly space, but when you consider this model is what amounts to a 1/8th-scale model of a professional sounding rocket, we're talking the equiv. of 75 MILES which is, of course, Space.

-Ricky

**Assumes:

1- Payload of 120 grams; radio direction transmitter, 1 x 200MM parachute, 1 x 20 meter streamer, 1 release-packet of Zerox toner

2- Burnout of stage 1 at 2.56 sec. ET

3- Release of spent stage 1 at 2.80 sec. ET

4- Coast of stage 2 in 'boosted dart' mode to 11.00 ET

5- Ignition of stage 2 at 11.00 ET

6- Coast of stage 2 in 'boosted dart' mode to release of parachute at 34.00 ET

50K feet in 34 sec. = a 1002 MPH average speed. Rolling on the floor laughing my a.. off!

Suffice to say that I was serious enough about this endeavor that 'twas all in Microsoft Project, complete with CAD models, reams of spreadsheet sims, etc. Laughing out loud!

The Development Project
Whoa!! That is wild! The biggest I launched was the D Powered Honest John. Every time it landed, it cracked a tail fin. (views: 8)
Greg H. -- Sunday, 26 November 2006, at 5:37 p.m.
Honest John
Thumbs Up for this Watch Smiley Maybe another watch-rocket-swap? Smiley Laughing out loud! Rolling on the floor laughing my a.. off! >> (views: 9)
Ricky Lee McBroom -- Sunday, 26 November 2006, at 6:06 p.m.

'cause I've got that exact kit out inna garage, too! Rolling on the floor laughing my a.. off! Rolling on the floor laughing my a.. off! Rolling on the floor laughing my a.. off!

It's the late-80's reissue, though. More's the pity, as original '68-'70 versions in pristine condition have been known to fetch $250+ on Found on the Bay! !!

Mine's worth maybe $100... I am not happy!

-Ricky

Wow! I bought mine back in 1975 when I was in the A.F. in Tucson. Photon Disrupter was another, I had. Smiley Post contains no message text (views: 2)
Greg H. -- Sunday, 26 November 2006, at 6:25 p.m.

'Poor Man's' Watch Forum - Foro de Relojes Para el 'Hombre Pobre' - Horlogeforum voor de 'Arme Man'



< Back to 'blog index >