Thursday, December 31, 2009

Purchases!

I went after-Christmas shopping with mandachan yesterday. Amazingly, the stores weren't crowded, and I got good stuff.

At a local hobby store, where I had a gift certificate, I bought a pack of B6-0s, a new razor saw blade for my exacto knife, sheets of 1/4" and 1/16" balsa and 1/32" basswood, and an Estes Big Daddy kit.

I will not build the Big Daddy stock - I'll certainly beef up the motor mount reinforcement and replace the crappy plastic chute with a quick-link and nylon chute. I'll likely add a 29mm motor mount, and/or add 4 plugged 18mm mounts around the central mount. I might also do what others have and extend the motor mount tube up into the nose cone to serve as a baffle. Nose weight will be added for stability on larger motors - up to a baby H, possibly, and the fins reinforced with basswood or paper skins. I'll prolly also add rod-based motor retention, especially if I do upgrade to the 29mm mount.

At Borders, I bought We Were Dead Before the Ship Even Sank by Modest Mouse (the first CD I've ever bought myself, rather than borrowed from the library or my parents), and QED by Richard Feynman (about Quantum Electrodynamics).

Curses

The internet quit just as I was beginning to compose a post last night, so I broke my string of days with consecutive posts dating back to November. (My previous string lasted from July into November, and ended, again, with the internet out for a while).

Tuesday, December 29, 2009

Heli-roc

Over yesterday and today, I built almost the entire rocket. It went together with no problem; however, it seems a mite flimsy, so I'll be reinforcing it. More tomorrow.

Monday, December 28, 2009

Multi-Goon Pictures

I got some building done on the Multi-Goon these last few days.

I superglued all twelve fins on:
 

I have an engine hook, to be epoxied on, and a thrust ring on the inside:
 

And three interchangable motors mounts; 5x13mm, 3x18mm, and 1x24mm:
 
Posted by Picasa

Sunday, December 27, 2009

Mach Goon Painted

It was in the low 50s today, and the humidity was pretty low, so I went out and painted the Mach Goon. Coat of yellow, coat of red, then some yellow on the nose cone:
 
Turned out pretty nice, I think.

Posted by Picasa

Saturday, December 26, 2009

What to Buy...

One of my Christmas presents was a gift certificate to Apogee Components. I've got a lot of choice as to what to get. I've divided my choices into three main possibilities:

Smaller but unusual kits:
Apogee Aspire: 29mm machbuster / altitude model
Sunward CFX Six-Footer" 24mm super-roc

Larger 29mm models:
Cosmodrome Black Brant II: huge and cool-looking scale model
Madcow Bomarc: completely different from other large kits out there

4" diameter 38mm models:
Madcow Patriot
Madcow Phoenix
Madcow Little John
PemTech King Kraken



Thoughts?

Friday, December 25, 2009

Christmas!

I had an very nice Christmas; I hope all of you did too.

I got a Quest MLAS kit from my TRF Secret Santa; I plan to add nose weight to be able to fly it on motors larger than B^s, since it'd be a perfect match to 18/20 D13 reloads.

My parents gave me an Apogee Heli-roc kit. It looks to be difficult but fun. I like kits that don't use parachutes on streamers, though the three chutes on the MLAS look to be way cool.

My aunt and uncle got me a gift certificate to Apogee, which I'll definitely use to add a new rocket to my collection. Those possibilities will be next post.

I also got a number of books:
  • The Time Traveler's Wife by Aubrey Niffenegger (awesome novel)
  • The Design of Everyday Things by Donald A. Norman
  • The Physics of Star Trek by Lawrence M. Krauss
  • MLA handbook, 7th ed.
  • The Illustrated Guide to Aerodynamics
  • Illustrated Reverse Dictionary


I also got lots of candy and some other random items, plus a gift certificate to a local hobby shop.

Sorry, @eloh, but I didn't get a digital camera.

Thursday, December 24, 2009

Christmas Eve

I'm too tired to actually post right now...


so,

Merry Christmas to all, and to all a good night!

Wednesday, December 23, 2009

J. Random Hacker

A subset of the Jargon File is the Portrait of "J. Random Hacker". (Hacker here refers to a skilled programmer, rather than a "cracker" who attempts to damage systems). Even though I am just a padawan - I can program only in BASIC, the lowest of the low, on my calculator, I aspire to be an excellent programmer, and I completely recognize myself in the personality traits listed:

  • Appearance: Intelligent, intense, abstracted, thin. That's pretty much me.
  • Dress: T-shirts, jeans, sneakers. Casual and vaguely post-hippie. Likes black, not for the goth look but because it goes with everything, hides dirt, and makes dressing up (when needed) easier.
  • Reading habits: a range that astonishes liberal arts majors, with lots of well-thumbed books on a variety of subjects. Fond of technical maunuals and good sci-fi.
  • Interests: chess, intellectual games, wargames, music, Nethack, linguistics, theater.
  • Sports: likes competitive but not-team and non-contact sports. I like tennis and skiing. Also, other things like climbing, hiking, aviation, and diving.
  • Food: exotic food, often Oriental stuff like Chinese and Japanese. Also stuff like pizzas and microwaved burritos when working. Stir-fried random is good.
  • Personality traits: high intellience, ability to digest and retain large amoutns of information, intellectually broad but focused, control freaks about their work but chaotic and messy elsewhere, attracted by challenges and cool toys. I also possess the rare but hacker-common INTJ (introvert-intuitive-thinker-judger) Myers-Briggs personality type. Possible ADD / Asbergers. Strange sleep patterns.
  • Writing: tends to be better at writing than speaking. Bad handwriting and fond of block-printing. Tends to verb nouns (turning any noun into a verb rather than using a more general verb, which is allowed in pure-positional languages like Chinese, but not English). Tends to put punctuation after parentheses and quotes, which makes more sense than the prevailing method of putting them inside.

Tuesday, December 22, 2009

Multi-Goon

Because I have too much time (Christmas Break starts tomorrow at noon), one complete Baby Bertha kit, one minus the body tube and nose cone, and a whole bunch of fins, I have created... the Multi-Goon. Muahahaha!

The pointy end will be pretty standard, except for the double-length shock cord. I'll prolly use a quick-link to swap out chutes.

The firey end is where the cool stuff is. I have 12 identical Baby Bertha fins that'll provide excellent stability, and a 3/16" launch lug. I'm still finalizing the configurations and mechanics, but it looks like I'll start out with three swappable motor mounts - 1x24mm, 3x18mm, and 7x13mm. I may add 1x29mm, 1x18mm, and/or 3x13mm (tilted) mounts later, assuming I don't lose the darn thing.

Monday, December 21, 2009

Eric Gates

Rocketry lost one of its own today. Eric Gates, half of Gates Brothers Rocketry, passed away today due to an accident. He was an incredible high-power rocketeer - L3 certified, and fond of giant spectacular clusters, including a 3x upscale Sumo that earned them the cover of the 2007-08 Aerotech catalog.

Those on TRF may remember him posting as Porthos II. I never met him in person, but I learned a lot from his postings. Gates Brothers Rocketry is online here.

You might also remember him when he was on a Mythbusters episode, to assist the team with a ancient-rocketry myth. He served as an ambassador for our hobby.

He is survived by his brother, Dirk.

Rest In Peace, Eric. You will be missed.

Sunday, December 20, 2009

Slow day

Meh, nothing much to report today. I did all my Christmas shopping, my homework, and present-wrapping. I finished another book (I've been reading one every day or two recently). I played dominos. I read MLIA. I did finger pushups. I started reading 2 more books.

I did get a little rocketry done. I simulated a few more 13mm rockets - all are done except the clustered Twofer and the weird-shaped SS2. I also started repairing the shock cord of the Electric Mosquito which was getting all frayed.

Saturday, December 19, 2009

Odyssey on Openrocket

It took a while, but I got it simulated:


(Click to embiggen and de-fuuzzify).

The nose cone, which is in red, is a very strange shape, so I had to make in a really complex mix of nose cones, transitions, and balsa body tubes to make it look realistic. In order to attach fins to the lower tube, I had to make an invisibly thin transition between the white tube and it's not perfect, but I think it turned out ok. The simulation seems pretty accurate - roughly 130 feet for 1/2A3s, and 240 for A3s and A10s.

Screenshot was captured with the 'Snipping tool' under Accessories in Vista.

Friday, December 18, 2009

Random Aerotech News

Mostly from Facebook:

1) The 38mm case adapter systems are out and shipping, just in time for Christmas. 29mm adapters are next, which I will defintiely buy to use my 29/180 case for 120Ns and 60Ns loads, especially the G77 Redline.

2) Blue Thunder and Redline loads for the 24/60 case are being casted, with plans to test them in January or February and certify next spring. Once they come out, I will prolly buy the case.

3) Instructions for the Delay Drilling Adapter are up. It lets you use the Cesaroni Pro-DAT tool with AT reloads. Even though there's a very public feud between supporters of each company of the rocketry forums, the companies themselves are cooperating. Win!

4) Date codes for motors are YMDDMY. 001588 on my F23-4J = 08/15/08, and 000539 on my F32-4Ts = 03/05/09 (just 15 days before I bought them).

5) Apogee now carries the E20W, for $21.39 for two. Not a great price for an E motor, but I'll prolly pick up a pair sometime.

Thursday, December 17, 2009

Staging in Openrocket 0.9.5

I really love this program. It's a fast and accurate simulator, waaay above TIRASP running on my calculator, and free.

I've been trying staging on it with the mandachan. Changing motors is pretty simple, and the interface adapts perfectly well to multiple stages. I'm not sure what it'll do with clusters; that'll come with simming the Twofer. It even lets you set your own delay for motors, meaning that any motor can become a booster motor.

More tomorrow...

Takeapart: hard drive

It's been forever since I did one of these posts, but I got an old hard disk yesterday with instructions to make the privacy-protected patient data on it unreadable. That I did.

The thing was hard to open, with seven very tight torx screws. I got the outer six off with a standard flat-blade screwdriver, but then it began to slip, so I beat the last one with a hammer till it ripped out of the aluminium frame. It was a pretty simple design - circuit board on the bottom, single platter taking up most of the space. I took some pliers and flipped up a metal plate which held one of the two magnets. I pounded on the aluminum hard drive frame to bend the other plate, allowing me to slip a screwdriver under and lift up the other.

Thus, two perfectly good small hard drive magnets. The two of em held an office chair hanging from a hammer to a steel I-beam. Strong stuff - neodymium iron boron. At least 20 pounds of pull between the two, maybe more. Stick em together and slide em up and down the fall till they stick to a nail, you got yourself a stud-finder. They'll clamp thin wood like balsa real well. Also good for wiping hard drives and credit cards, wrecking speakers, and making spots on CRTs.

I then beat the metal frame till it spit out the platter, which I then beat with a hammer, ran with magnets, and otherwise turned into a nice piece of modern metal sculpture. The feebees could maybe salvage it, but prolly not.

Defintiely worth the effort.

Wednesday, December 16, 2009

The EGE hates homework

..because it keeps him from blogging.

On the other hand, I did finish my entry for the EMRR 'Roam the Site' contest. I got all of the first and second level questions and 7 of the third-level questions. Many were easy; a few required extensive searching, and one I got by pure luck - the first search result of 105.

Tuesday, December 15, 2009

Teenage depictions in literature

And now, for something completely different:

As those who know me have surely noted, I read a lot. Close to a book a day during the summer and weekends, and still several a week during school despite my busy schedule and the gobs of homework my teachers love. I tend towards a majority of nonfiction - math and science, history, biographies, and the occasional subversive stuff; but I do read a lot of fiction. Much of that fiction is military fiction and thrillers, but once in a while I'll read conventional 'young adult' fiction if it looks interesting.

What often makes a fictional book, especially young adult stuff, stand out for me is having a believeable strong teenage protagonist, which is very rare, especially for female protagonists. Most teenagers are protrayed as significantly less intellectually developed than adults, with minds more like children, and usually incredibly vain, clueless, and anti-intellectual. While certainly I know teenagers like that, they are not necessarily the majority, and I hate reading a book with a wimpy, boring protagonist.

Books that have a strong teenage protagonist are relatively rare; I can only name 4 that I've read an enjoyed off the bat. Deadline, by Chris Crutcherson, which I talked about a while back, is perhaps the best. The 18-year-old narrator is highly intelligent and acts like an adult; in fact, he faces his death more eloquently and sanely than any of the adults do. I see much of myself in him, notably his intellectually rebelious attitude, his penchant for confronting the biases of techers, and his statement that he's always felt like an adult - he's never felt like he had the mind of a child.

Ender's Game by Orson Scott Card is prolly the best book I have ever read. It's witty and engagaing, with elegant social commentary and uncannily accurate predictions about the future. The characters are not actually teenagers but a small crop of the most intelligent children between the ages of 6 and 12, but they talk and act exactly like teenagers, except that there's none of the teenage sexual tension. Many adults claim, as Card notes in the introduction, that kids supposedly don't talk and act like that, but I can ascertain that they really do, and in fact I love how accurate the interactions really are. It's part of a tiny number of book that I can actually imagine myself as the protagonist in.

Two others that I've read recently have also struck a chord. Ripple Effect by Paul Garrison (pen name of Justin Scott), a thriller set on the open Pacific Ocean, has a major subplot featuring the 15-year-old daughter of a major protagonist sail alone across half the Pacific to rescue her father. She's a well-written character - independent, extremely intelligent, and still humorous. And in The Misfits by James Howe, which I just started reading, the male protagonist and a female friend - both age 12 - are strong, intelligent characters who think like adults, not children.

I'm not quite sure why I so strongly prefer characters like this. Perhaps it's because I see in them an idealized version of myself - perfectly confident, always intelligent, and free from the pathological wimpiness and obsession with the boredom of everyday life that afflicts most teenage characters. Perhaps it's because I tend to pick friends like this; most likely it's both - I perfer characters that I can either personally identify with, or who I know I would get along well with.

It's certainly part of why I have recently started enjoying Castle on Monday nights. Castle's 15-year-old daughter, Alexis, is one of the best-written characters, with the same personality characteristics as the other characters. She adds the voice of the average teenager to the show, while still adding a voice of logic and sanity that you don't see from most teenagers on TV. Heck, she's usually the voice of the reason to the entertaining but bumbling Mal Castle.

Thoughts?

Monday, December 14, 2009

Meh

I've got the WAC Corproal fully simulated and the Jinx partially done. But I have plenty of homework left to do, so this is likely all I'll have time to post tonight.

Sunday, December 13, 2009

First round of OpenRocket simulations

I've been playing with Openrocket 0.9.5, a freeware rocket simulation program that's very similar to SpaceCad, for a few days now. It's not perfect, but it works pretty darn well for freeware. I'll have general comments later on, but for now I have a few simulation results to compare to my TIRASP sims.

Gauchito:
MotorTIRASPOR
1/2A3-2T79 ft103 ft
A3-4T185 ft213 ft
A10-3T181 ft199 ft


Very similar results.

Machnum Force:
MotorTIRASPOR
D12-7986 ft942 ft
G78-10G4463 ft4033 ft
G80-13T5042 ft4534 ft
H128W-L5509 ft5360 ft
H165R-L5733 ft5047 ft


Pretty similar results for a tiny rocket at high speeds on large motors. The discrepency with the H165 is because Openrocket says that the H165 has exactly neutral stability, which would cause oscillations that'd rob it of altitude.

Wizard:
MotorTIRASPOR
1/2A3-4T208 ft250 ft
1/2A6-2137 ft193 ft
A3-4T504 ft494 ft
A6-4Q473 ft426 ft
A8-5433 ft451 ft
B4-4937 ft767 ft
B6-6938 ft776 ft
C6-71671 ft1305 ft


No idea why the B4, B6, and C6 give such disparate results here.

Saturday, December 12, 2009

Hardware Store Run

My folks were heading to the hardware store today, so I tagged along to see if there was anything worth buying. Turns out there was.

First I got two packages of 3 each 1/8" quick links; 1" long. Works out to under a dollar per. A great price for quick links that small, which are perfect for attaching parachutes to rockets, even ones as small as 1" diameter.

Next came... well, something. I'm not sure exactly what the original purpose was, put it's essentially a 600-foot roll of 1" wide orange streamer material. It's a bit thinner than I'd like, but for 4 bucks I'm not complaining.

Finally, I decided to buy stuff for a motor retention system, particularly for a LOC Viper IV which I hope to buy soon. I bought a 12" length of 10-24 allthread (threaded rod), a package of 12 #10 nuts, and a package of 10 #10 brass washers. Interestingly, the #10 brass washers were smaller than #10 galvanized steel washers; I chose the former because I was afraid that the larger steel washers might deflect thrust from a wider-nozzled D12 motor.

Friday, December 11, 2009

Goonie Ideas

I've got one Baby Bertha kit left, and several ideas as to what to do with it:

Goonie Patriot or Bullpup

Goonie Saturn V

Goonwing - with a Transwing-style glider

Power Goon - with either a 24mm or (more likely) 29mm mount

Goonie Kraken

Heptagoon: 14 fins and 7x 13mm motor tube (could fly on any number from 1 to 7 motors)

no name ideas yet, but with 3x or 4x canted 18mm motors

Scissor-wing Goon, with a working glider.

Thoughts? More ideas?

Aerotech O-rings and Insulators

A guide to Aerotech o-rings and insulators for the 29-54mm HPR sizes.

Also, A preview of 54/426 instructions with the new 54mm aft closure (which allows use of cheaper 38mm nozzles without changing the thrust curve) and 38mm spacer instructions.

All from their Facebook page.

Thursday, December 10, 2009

Mach Goon Building finished!

And the masses gave a sigh of relief, because nevermore would they hear the horrors of building the Mach Goon.



All it needs now is paint, which will happen when the weather gets above 60. You know, March.

Wednesday, December 9, 2009

Completely Random Fact

The admiral commanding the fleet involved in the Gulf of Tonkin Incident was the father of Jim Morrison of the Doors.

Tuesday, December 8, 2009

Crazy Idea

Something occured to me today. The grains for the G71R and G53FJ are the exact same size, with the same-sized C-slot.

That means that, theoretically, one could buy one of each, and use of grain of each for two black/red motors. The G53 and G71 have fairly similar regressive thrust curves, with similar burn times, so they'd theoretically be compatible.

The G53 is 91Ns and the G71 is 107Ns, so theoretically each would be about 99Ns. The G53 has a slightly longer burn time at 1.7 seconds. 99/1.7 = 58Ns, so this would be roughly a G58 depending on the nozzle shape.

Obviously this would pose risks from mixing propellants and would be considered an EX motor, but I could possibly try it at NERRF, which allows EX launches, once I turn 18.

Thoughts?

Monday, December 7, 2009

An Apology

Because I've been pretty lax on posting lately - for the last month, really. I've skipped a few days in the last month, and many days have been short posts, a few without any real content.

Basically, junior year is catching up with me. For the first month or two, most of what we were doing in class was review. I was able to stay ahead with little work, and I had lots of spare time for blogging. Recently, my classes have been entering new territory. I'm learned something new in calculus every single day (as I should be), chemistry is getting harder, and history is moving into the Vietnam War era which I'm not too familiar with. I'm spending 2 or 3 hours every night on homework, and that's a lot of time that I'm not blogging and not finding cool stuff on the interwebs. Add my job and a few extracurricular activities, and I don't have a lot of time. Mandachan is experiencing the same problem, only to a lesser degree because she has a bit more common sense than I do, plus she has the natural advantage of being cooler than I am.

Blogging isn't the only thing that's suffering for me. I'm sleeping only 4 to 6 hours a night, which is starting to catch up with me. My grades aren't slipping, but I find myself less able to complete calculus homework late at night, and I'm not practicing my trumpet nearly as much as I should be. I may even have lost a friend, though I'm really hoping we can patch things together.

Fortunately, not all is lost. My history thesis paper is done and over with, which gets a lot of stress and expended time off my back and will hopefully bring some stability to my history grade. I'm beginning to manage calculus a little better, and my time management skills are slowly improving. I'm also getting better at staying sane on little sleep, and Chrsitmas break is just 16 days away. The occasional snow day will certainly help me out a great deal with the extra time, extra sleep, and stress-free day without homework to do.

So, my promise to you remains the same. I will do my damndest to get a new post up here every day, and most of them will be more witty, insightful, and full of information. A few here and there will be worthless go-se, but even more will have pictures, odd yet insightful ramblings, links to other folks, and just plain cool information. A lot will be just before and after midnight, but there'll be at elast one per calender day, often more.

As always, I really appreciate the comments all you folks have be leaving lately. It's what makes all this work worthwhile.

Sunday, December 6, 2009

Irony

My thesis paper, which I just finished printed out, is officially due tomorrow, December 7th.

My topic: Pearl Harbor.

Even more Mach Goon building

I know you all are getting tired of pictureless posts. Pictures will come eventually.

The little guy, though, is coming along nicely. There are 3 coats of wood glue on the nose cone now, and it's sticking pretty well. There's two coats on the body tube, and currently I have some of the second round of fillets drying.

I also attached the shock cord to the wall of the body tube and the inside of the nose cone with epoxy clay, which also serves as nose weight.

Amazingly, I'm actually almost done with the Goon. Once the fillets and outer surface are done being covered in wood glue, then it'll be structurally ready for Mach flight. All I'll have to do is attach the streamers, attach a launch lug, and paint the damn thing orange so it's more easily findable than the brown Machnum Force.

I'm debating the lug size. I really should use a 1/4" lug because it is technically a high-power rocket, but a 3/16" or even 1/8" lug would be just fine for its size and weight, and would certainly save on drag. I'll prolly compromise and use a 3/16" lug.

Saturday, December 5, 2009

International Google

Found on the xkcd fora:

If you're in a foreign country, but want to use the US version of google, simply go to google.com/ncr. It automatically redirects to the standard - US version; i.e. No Country Recognition.

Also, possibly a way to get around some censorship firewalls.

Friday, December 4, 2009

Hey, it works

So far, since I roughened up the cone, the coat of wood glue on the Mach Goon's nose cone seems to be holding well...

APCP Chemistry

Happened across some information about Ammonium Perchlorate Composite Propellant that I think is pretty interesting.

The chemical formula is NH4ClO4. It burns with aluminum, the fuel of choice in white motors, like Aerotech's White Lightning, Cesaroni's White Thunder, and NASA's SRBs, with the equation 10Al + 6NH4ClO4 → 4Al2O3 + 2AlCl3 + 12H2O + 3N2. (source)

An elastomer binder like PBAN or HTPB is added to make the propellant the proper consistency and to add fuel.

The ingredients, of course, determine the color of the flame. Copper added will turn the flame blue and burn cleanly (as in Blue Thunder propellant), but it's notoriously hard to make a pure deep blue (hence the light blue color of Blue Thunder), and in fireworks it takes much skill to develop a good blue. Barium turns the flame green; Barium chloride produces a pure green while barium oxides add the yellowish green of Mojave Green. Strontium nitrate (SrNO3), either added to AP or in place of it, produces the brilliant red of Redline propellant.

Sparkies use a metal powder, usually titanium, that generates the black smoke and yellow sparks. I do not know what creates the black smoke of Black Jack and Smokey Sam motors, or the light yellow of Warp Nine.

Cesaroni Pink propellant, which looks purple, could either be from rubidium compounds, or a careful mix of red and blue.

It appears that there are colors that could be used that aren't. Sodium compounds produce a brilliant yellow flame that overpowers many other colors, while calcium chlorides make orange. Both would make for very cool motors.

The Wikipedia article on APCP has much good information, including some burn configurations. The burn rate of APCP is between 1 and 3mm per second at STP and 6-12mm/sec at 68 atm, and increases at roughly an x0.4 rate with pressure.

This site contains much good information on motor design and grain configurations.

Thursday, December 3, 2009

Pseudophenolic

Which surprisingly, is not a new word - Google returns 286 results.

In this case the pseudophenolic is my coating of the Mach Goon with wood glue, which forms a hard plasticy shell - somewhat similar to a true phenolic material, on the cheap. Wood glue of course binds excellently to wood fins, kraft paper body tubes (including the glassine outer layer), and itself, but unfortunately not well to certain plastics like the extruded styrene used in the nose cone of the Baby Bertha.

After one attempt, which sucessfully coated part of the body tube but not the nose cone, I tried again by roughing up the nose cone with sandpaper works. Tomorrow will tell if it worked, or just ruined the cone.

Wednesday, December 2, 2009

Really not much to add here

But I promised a post a day, so you go. Even though I wrote one at 1230 this morning, it doesn't feel much like the same day 23 hours later.

The third set of first-round fillets on the Mach Goon is currently drying. The fillets are turning out pretty small, so I'll alternate fillets and coating the entire rocket till I've got 3 fillets and 2 layers of wood glue. That should be enough to hold it together through Mach 1.1.

I just took a practice test for the SAT II Math level 2 test. It wasn't spectacularly hard, but I did make a few stupid mistakes, that I normally would have caught by checking over my answers, but I didn't because I got bored of it after finishing all the questions but one. Why have I gone through every math class offered in my school system, up to and including being halfway through AP calculus, and I never learned matrix multiplication? Xi niu quinwa cao de liumung.

Old Aerotech Documents

While searching for an Out-of-production (OOP) motor on Google, I discovered a really cool document filed away somewhere on the Aerotech website. It's a collection of old certification sheets that document every Aerotech motor certified between December 10, 1982, and April 25, 1997.

Almost every one of the reloads listed is still produced, but over half of the SU motors are now OOP, including a number of very interesting motors.

They include a number of booster motors, including D7-0, E6-0. E10-0, F10-0, F15-0, and F20-0. (Each with a family of short, medium, and long delays available as well). It gives no mention of size nor propellant, but they were the earliest motors listed, being from 1982, and since they were booster motors I'm curious whether they were BP or composite motors.

By 1988, the following motors were certified for sale under both the Aerotech and Enertek brand names: D7, D8, E6, E10, E15, E28, E30, F9, F10, F15, F20, F25, F30, F41, F44, F60, and F80. Of those, E6s and F10s are currently manufactured by AT for Apogee, and Aerotech offers E15, E30, and F20 motors, which may or may not be the same then and now. The E28 is certainly not the same, as there were no reloadable motors certified then.

The D21 and the now-OOP E25, F32 (the old version), and F72 were certified in 1990.

In 1994, the 18/20, 24/40, and 32/60-100 RC hardware were certified. The 18/20 case was then available for B6-2,4,6T; C4-3,5W; C6-3,5,7W; C12-4,7,10T; and E27-4T loads as well as the D13 and D24 still available today. I would certainly buy an 18/20 casing if B-E loads were available rather than just the 2 D loads. The 24mm loads certified were all those available now, plus several longer delays not currently available.

HPR RMS became available in 1994 as well with 29/180 and /240 and 38/240, /360, /480, and /600 casings and Black Jack, White Lightning, and Blue Thunder loads. There were also a number of 29mm SU motors certified that year: H35-6,10J; H55-6,10W; H70-6,10,14W; H90-6,10W; and H120-6,10,14T; plus the following 38mm SU motors: H65-10,15W; H145-10,15T; I95-10,15W; I132-10,15W.

Later that year, they certified even more motors: 29mm SU G25-5,10,15W; G40-4,7,10W; G80-4,7,10T (the old style G80 that was recently phased out); G80-4,7,10W; G125-10,15T; 24mm SU G42-4,8,12W; G55-5,10,15W; G110-5,10,15T; and the 29/40-120, 29/60, and 29/100 systems and reloads.

1996 saw the introduction of 54mm and 98mm HPR reloadable systems and loads, as well and the 29mm SU H124-6,10,14FJ and the 38mm SU H45-5,10,15W.

There were a few 18mm SU motors certified in 1997: C4-3,5,7; D3-3,5,7; these were eventually sold by Apogee till the fire a few years ago. A number of 54mm SU motors were also certified: I65-10,15W; I115-5,10,15W; I140-5,10,15T; I220-5,10,15T; J100-10,15W; J125-5,10,15W; J220-10,15W; J285-5,10,15T; J355-6,10W; J455-5,10,15T; J700-5,10,15,20T; K250-20W; K400-20T; K900-15,20W; K1050-PW; K1500-15,20T.

I'm pretty sure that a number of these certified motors were sold by other manufacturers. I wonder why so few of them are produced anymore. Anyone who's been around for a while?

Tuesday, December 1, 2009

The Mach Goons has fins now

But no pictures. It's so sad.

But it does have all six fins nicely glued on with wood glue. I even managed to get them almost perfectly aligned by hand. Now come 2 layers of 12 fillets each. Oh fun...

Monday, November 30, 2009

More Mach Goon Building

I cut a 3' length of 1/8" kevlar for the shock cord and tied it to the eyebolt; I then put a few drops of CA on to keep the knot from unraveling.

I glued the motor tube into the body tube with wood glue, and the first fin is now drying. It'll take prolly the rest of the week to glue on the other 5 fins and double-fillet them, but the work should allow the cheapo clementine-box fins to withstand the forces of 850 mph. I'll also layer wood glue on the body tube and nose cone at the end of building; it'll add a tenth of an ounce or two, but add significant strength to the body tube.

Here's a picture of the parts, taken before the last round of gluing:















I checked on TRF and it appears to be allowable per CTI instruction sheets to remove part of the ejection charge.

Also, I am now using gmail in the 'ninja' theme. I may never go back.

Sunday, November 29, 2009

Mach Goon building

I finally got some time today to work on the Mach Goon.

First came the fins. I cut six identical fins out of 1/8" light plywood from a clementine box. They're 2.7" wide, with a 3" chord on the root and 1.5" on the tip. I filled holes in two of them, and they're currently drying from a coating of wood glue. I may add paper skins for strength as well.

I ran a few CP calculations of the Mach Goon that turned out pretty well. I really only need 4 fins to keep it stable, but I'll probably add 6 just to ensure stability, even if a fin or two snaps off from the stresses of flight.

Next came the nose cone. I cut off the attachment loop and much of the shoulder, leaving just enough to keep it firmly in the body tube. I added a bit of weight to the front of the nose cone, and I'll probably add some lead shot eventually to keep in stable.

I decided that the two 48" by 1" streamers that I recently bought, plus perhaps one more, should be perfect for bringing it down safely yet quickly, with minimal drift. The rocket itself will weigh no more than 3 ounces, and the Pro38-1G case just a few ounces more. if absolutely needed I'll get a bigger streamer, or use a very small parachute.

Finally, I cut the motor tube. I wound some masking tape around the 38mm LOC Precision kraft paper tube, and cut it to length (6") with a small x-acto saw. I marked off 1/2" from the factory-cut end, cut just a little bit, and then unwound the outer 4 layers from the other side. It now fits perfectly inside the BT-60 of the Baby Bertha tube. The 1/2" that sticks out will the the attachment point for the masking tape to hold the motor in. This rocket will have to withstand a full 38mm ejection charge unless I can modify the reload, which is not as easy with CTI loads.

Saturday, November 28, 2009

Thoughts on the Mach Goon

I've finally gotten to the point where I'll actually be building the Mach Goon soon. Most of the design is settled; however, there are still 2 things I need to figure out.

First and foremost is motor size. I have 4 options: Cesaroni Pro38-1G or 2G, or AT 38/120 or /240. Simulations using a variety of motors are below; Cesaroni motor data is estimated and not exact. Parameters: 3oz, 1.65" diameter, Cd = 0.6.
SU | G80T: 3066 ft, Mach 1.11. (137 Ns)
38/120 | G61W: 3276 ft, Mach 0.88. (120 Ns)
38/120 | G67R: 2985 ft, Mach 0.85. (110 Ns)
38/120 | G69N: 3486 ft, Mach 1.02. (137 Ns)
38/120 | G339N: 2959 ft, Mach 1.29. (110 Ns)
38/240 | H123W: 5256 ft, Mach 1.30. (230 Ns)
38/240 | H148R: 4368 ft, Mach 1.27. (220 Ns)
38/240 | H242T: 4554 ft, Mach 1.62. (230 Ns)
38/240 | H669N: 3790 ft, Mach 1.72. (220 Ns)
Pro38-1G | G115WT: 3401 ft, Mach 1.15. (141 Ns)
Pro38-1G | G185VM: 2908 ft, Mach 1.19. (128 Ns)
Pro38-2G | H152BS: 4813 ft, Mach 1.45. (279 Ns)
Pro38-2G | H400VM: 4327 ft, Mach 1.93. (255 Ns)

Several things are clearly obvious. First, the 38/120 case is right out - the only 2 motors in it that break Mach are Warp-Nine reloads, which I can't use because they can't have delay grains or ejection charges, and there's no room for a timer.

Second, that most of the two-grain reloads - AT 38/240 and CTI Pro38-2G - would not be good, because many of them would be pushing Mach 1.5, and a few even get past 2000 fps. At those speeds, there's no way I could ever manage to hold fins on without an absolutely perfect epoxy job. Hence, the best choice will be the Cesaroni Pro38-1G case with a G115 White Thunder or G185 Vmax reload. The G115 was the advantages of being far easier to track and offering slightly gentler acceleration; the G185 brings higher speed and a lower altitude - within reason, even - to recover from.

Third, note that a 29mm G motor can, theoretically, break the sound barrier. However, an complete Aerotech 29/120 case is actually more expensive than a 38/120 casing, as is a CTI Pro29-2G system including the rear closure, which is not needed on their 38mm reloads. The G80 is then within reason, but I'd prefer the 1G case since, if I do get it back, then I can fly G69 sparkies in it!


The second issue, the fins, I'll deal with later today.


Motor data from Thrustcurve.

Massive Price Sheet

After a few hours of work, I've compiled a massive price list of almost everything imaginable related to rocketry. I've got Quest MMX motors, every motor type sold by Estes, every Aerotech single-use motor (except the mysterious I350R-10 and K250W-P, which no-one seems to sell), all Aerotech / RouseTech reload cases and AT reloads sizes 18mm-38mm (except the 24/20-40 and 32/60-100 RC glider cases, which again are evry very rare), all Cesaroni Pro29 and Pro38 cases and reloads, and a small avriety of igniters, etc.

It works out to approximately 159 items - that's 1431 cells, of which approximately 800 are filled with prices, and 600 are not a valid product - vendor combination.

The vendors are:

Apogee Components
Balsa Machining Service
Discount Rocketry
Giant Leap Rocketry
Hangar 11
Hobbylinc
Red Arrow Hobbies
What's Up Hobbies
Wildman


I plan to add more soon - AT and CTI motors up to 98mm, the Aerotech RC motors, Quest BP motors, and perhaps other reloadable motor systems like Kosdon, Loki, AMW, Gorilla, etc.

I'll post it for all to see on Google Documents eventually, but if anyone wants a copy now, drop me a line - my emails are found on the link at the very bottom of the page.

Friday, November 27, 2009

Watching Goldeneye

Means you get the real post in a few minutes.

Thursday, November 26, 2009

Thanksgiving

I'm off to the cousins to eat delicious turkey and pie. I'll be back tomorrow.

Wednesday, November 25, 2009

Black Paint is my Friend

I got a lot done tonight with nothing more than a little bottle of black paint:

-- Painted the new fin and spin tabs on the Screaming Yellow Zonker, plus went over a few areas to make the entire fin can a nice monochrome black. Looks very nice.

--Painted the Great Pumpkin's nose shroud black, as well as covering up the glue lines on the foam transition from the repairs.

-- Touched up the nose cone of the glider pod, and the fins on the Odyssey.

I also glued the baffle in place in the Great Pumpkin, so it'll act more as a baffle and not a blockage.

Tuesday, November 24, 2009

Remembering Matty B.

This afternoon, Matt Buriak, a junior in my school class and a friend to all, passed away. He suffered an aneurysm on Saturday and despite the best efforts of the best local and state doctors, he fell into a irrecoverable coma. Matt was an organ donor, and at least 3 others' lives will be saved and improved thanks to him. Matty B, we will remember you forever.

CATO 155 pictures #3

This series of three pictures is all of my 29mm pyramid lifting off on a G71-4 Redline. They were taken by mandachan on a camera set to burst mode at 3.5 pictures per second (~0.29 seconds between frames). Even though the motor chuffed, she managed to nicely capture it.

Chuffing at ignition:
 

Under full power; note the red flames reflected in the bottom of the pyramid.
 

The smoke trail.
 

Once again, the awesome pictures are courtesy of the wonderful mandachan.

Previous pictures here and here; launch report here


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CATO 155 Pictures #2

First off is a historic flight... Al Gloer getting off the pad first!

His and the other rocket (on the right, which took off a second later) are both PemTech King Krakens flying on Cesaroni G69SK sparkies.
 

Here is the Great Pumpkin, my 4" diameter pumpkin lofter, sitting boringly on the pad:
 

And igniting the G53-5FJ motor. It's not actually on the closer LPR pads, but on the mid-power pads directly behind but further away.
 

And under full power:
 

Once again, the awesome pictures are courtesy of the wonderful mandachan.

Previous pictures here; launch report here

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LHS Jazz Band at MGM Grand

A while ago I got a request for videos of my high school jazz band. Here are four videos of us playing at MGM Grand at Foxwoods:

Short Skirt | Long Jacket (Cake)

Spinning Wheel (Blood, Sweat, and Tears)

Fantasy (Earth, Wind, and Fire)

And our signature song, Frankenstein (Edgar Winter band)

I'm the shorter of the two trumpets, between the bass and the rest of the brass section. Enjoy!

CATO 155 Pictures #1

Presenting: the flight of the Mozzie, as captured by my dad.

At the moment of ignition of the E23-8T:
 

Liftoff:
 

Way up in the sky, near apogee at ~700 feet. This one was darkened in Picasa to see make the smoke trail visible and enhance the clouds:
 

Coming down under the parachute; click to embiggen and to see the Mozzie in the center of the frame.
 
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Monday, November 23, 2009

1/2A3-0T

I'd like to launch the mandachan, which is a 13mm minimum-diameter rocket, with two staged motors. Unfortunately, there are no currently produced 13mm (or smaller) booster motors, and the promised Estes A10-0T is nowhere in sight. So, I took a 1/2A3-4T motor, of which I have several, and modified it. I used a sharpened screwdriver to pick off the clay cap, which I will prolly discard, and the ejection charge, which I will keep. Both of those were loose-grained and came out almost immediately.

However, the delay grain was much different. It was almost 3/8" of densely packed material that took almost 20 minutes of scraping to get it all out. However, I managed to get all the way down to the top of the blackpowder grain. It's effectively now a 1/2A3-0T.

Dead Tree Edition #2

I just finished the rough draft of my junior History thesis paper, nominally 5-7 pages.

Mine:
9 full pages plus 2 lines, 12 font doubled-spaced
14726 characters
2924 words: exactly the same as last year's Dead tree edition
95 sentences in 11 paragraphs
4.8 characters per word
30.7 words per sentence
8.6 sentences per paragraph

I expect near 10 full pages in the final draft. It's an argument that the attack on Pearl Harbor was actually a military failure for the Japanese. I'll post the final draft text eventually.

Sunday, November 22, 2009

Repairs

The foam transition section on the Great Pumpkin is being glued back into place.

Glider #2 has a new tail fin.

Glider #3 has its glider hook reglued.

The glider boost pod has its bent tube stiffened and repaired.

The Screaming Yellow Zonker has a new spin fin and a second spin tab that are currently gluing into place. The second spin tab will allow spectacular spinning flights on As and Bs as well as Cs.

Saturday, November 21, 2009

Launch Report #35: CATO 155

Today was an excellent launch day. 60-degree temperatures, little wind, a clear field and sky, and my dad, a friend, and mandachan were all there to watch.

First came the gliders on a B6-2. One glider (#3) had its hook broken off at ignition, and it didn't make it off the bad, but the other (#2), hung on all the way to ejection at around 500 feet. It glided for well over a minute, prolly closer to 2, before hitting the trees. It bounced down 80 feet of trees to the ground, amazingly losing only the tail fin. Both gliders will fly again.

Second came the Mozzie on an E23-8T. I drilled the delay out to 5 seconds, but it was still 8 seconds from burnout to ejection. It boosted fast and smooth to around 650 feet and ejected at about 500, recovering with no damage. Es are a good fit for the Mozzie.

Third was the Screaming Yellow Zonker! It had a cool sound and nice spiral smoke trail. It recovered right near the pad, mysteriously missing one fin, which I'll replace.

Fourth was the Great Pumpkin on a G53-5FJ. The Fast Black Jack (aka Black Max) motor ignited instantly and it boosted fast and straight. The 'punkin' inflated its chute instantly and it drifted off into the distance, remaining in sight for 2 minutes and 33 seconds. The main body of the rocket did not deploy its chute and the foam transition broke a bit; it should be easy to repair.

Fifth was the Twofer on a pair of A10-3T motors. Despite aspersions cast by other fliers, it boosted fast and straight with a just a tiny bit of spiraling.

Sixth was my 29mm pyramid on a G71-4R Redline. It was my third flight of the day on my new 29/40-120 case, which I now really like. It flew perfectly straight to about 300 feet. The delay was long and ejection was simulataneous with impact, but it was amaingly undamaged. The light ply and wood glue held.

I flew 6 rockets on 7 motors today, including 2 G and 1 E motor, which makes it my second-highest day in terms of impulse flown, next to NERRF 5 where I flew 1 F, 1 G, and 2 H motors.

Total since September 29, 2008: 1752 Ns (36.9% K motor).

Mandachan took some awesome photos; I'll post them soon.

Friday, November 20, 2009

Modifying Aerotech Delays

I bought an E23-8T on a whim, because it was 6 bucks, a pretty good price for a single E motor. Unfortunately, the 8-second delay is not very good for any of the 29mm rockets I have.

However, Aerotech has a very helpful way of changing that. On the excellent Resources tab of their website, I found a document that tells how to drill out their delays for shorter delay times. Simply take a 3/16" drill bit, and by hand drill out 0.024" to 0.031" per second of delay - just over 1/32" per second. The drilled-out section then faces the ejection charge in the final assembly.

Interestingly, they also state that the delay scraps should be electrically ignited safely outdoors for disposal, rather than simply put in the trash. I plan to test this with either a G53-7FJ or E23-8T on Saturday.

Progress

My computer should be back tomorrow. Maybe. Hopefully.

The Nike Goon is functionally finished. The white, red, and yellow paint job came out perfect; now all it needs is 'United States' painted in black down the side.

The Great Pumpkin is also finished. I used a chunk of epoxy clay to glue on the shock cord, and then glued on the forward section with wood glue. I put 2 1/4" launch lugs on balsa standoffs, and it was completed. I spray painted it freeform, without masking, so the color blended together. The upper section is black, and the lower section a mottling of yellow and red. Looks pretty nice, actually.

Planned flights for Saturday follow. Several motors are listed for a few that I'm not sure what motor I'll use with.

10" Pyramid: G71-4R: ~200ft
Mozzie: E18-4W: 785ft; E23-5T*: 655ft
Nike-Apache: E18-4W: 403ft; E23-3T*: 321ft; F23-4FJ: 508ft; F32-4T: 667ft; G53-7FJ: 1113 ft
Great Pumpkin (10oz rocket + 10 oz pumpkin and chute): F32-4T: 485ft; G53-4FJ*: 748ft

* drilled delays. See next post.

Twofer: 2xA10-3T: 513ft
Nike Goon: B6-4: 350ft; C6-5: 650ft
Glider (2+3)**: B6-2: 300ft
mandachan!: A10-3T: 500ft
Screaming Yellow Zonker: C6-5: 1000ft
Astron Invader: B6-2: who knows! It'll loop, that's for sure!

** Gliders #2 and #3 on a single boost pod

Sunday, November 15, 2009

Building updates again, because I do nothing else

The Nike Apache is almost completely finished. All four fins are filleted, as is the launch lug, and the last fillet on the motor mount is drying. I'll put a coat of primer and maybe one of white on tomorrow, then red and yellow for the fins on tuesday, assuming it doesn't rain any more. It'll fly on saturday at CATO 155 on either a B6-4, or a C6-5 if it's not windy.

The Great Pumpkin is also coming along well. All four through-the-wall fins are glued to the motor mount and filleted, and the motor mount is glued into the body tube, with the final glue joint drying. I put the baffle in, captive but not glued in place, and then glued in a 2" ring with a 1" hole about 6" from the top. This lets the baffle also serve as a piston to further protect the parachutes from the ejection charge.

The nose section / payload compartment is also nearing completion. The protective glue layer on the foam transition is dry, and the compartment is currently gluing to the transition. I just need to make the nosecone and glue the 'pointy end' to the 'firey end', and it's practically finished and ready for painting (orange and black, of course!).

Saturday, November 14, 2009

Building Update

My computer is, of course, still out of comission, but I'm able to use my parents' computer a bit.

I've gotten quite a bit done on the Nike Goon and Great Pumpkin over the last few days. The Great Pumpkin has most of its subassemblies ready to assemble. The motor mount is glued together (except for possibly a kevlar shock cord) and and the fins (1/8" balsa) are cut out, although I still need to sand them and cut the TTW (through the wall) tabs, which will anchor them to the motor mount. I've coated the entire foam transition piece with wood glue, which'll give it strength, make it easier to finish, and lessen the chance of it getting dented or crushed. I still need to create the pattern for the single-use paper cones that'll serve as the nose cone.

The Nike Goon is also coming along well. I cut the fins out last night, coated then with wood glue for strength and to aid finishing, and glued them on today with superglue. The motor mount is glued in, and it and the fins are getting wood glue fillets for strength. I intend to be able to fly it on anything from an A8-3 to a D21-7T. I also glued the shock cord in; after the fillets dry, i'll be all ready for the paint scheme of white body and nose cone with 3 red fins and 1 yellow.

Also, the Buckeyes won today, 27-24, in overtime. Over UNDEFEATED Iowa. They're now Big Ten Champions and headed to the Rose Bowl. Go Bucks!

Friday, November 13, 2009

Just checking in

It'll be a few days before my computer is back in operation. Till then posting will be light but building will be much. The Great Pumpkin is coming along well.

Thursday, November 12, 2009

Well, this sucks.

My computer got a virus last night. It seems to have managed to disable Norton Antivirus, which is one of the best antivirus programs out there. My computer is in capable hands, though, and most of my data is backed up. However, I won't be blogging much for a while; this post is from the local library which I'm at for a few minutes today. Hopefully it'll be fixed in time for CATO 155 next saturday.

Tuesday, November 10, 2009

Some actual building!

Amazing, I know.

Most of the work was on the Great Pumpkin - my pumpkin lofter for the November 'Pumpkin Chunkin' contest at CATO. It'll be 4" maximum diameter and about 30" long when finished.

I knew I needed a 4" payload bay for the pumpkin, but I only had 3" tubing, so I cut a 6" length, cut a slit, and glued another piece across the opening to form a 6" piece of 4" tube. I've also glued on a few other bits for reinforcement.

I found an old foam cone, and got permission from my mom to cut it up. I cut a 2" core out with a hole saw, and it now will form a nice solid transition from the 4" payload section to the 2" main body tube. It's currently gluing to a 4" plywood ring, which I cut out with a handsaw.

For the motor mount tube, I cut a 6.5" section of 29mm tube. I took two 1/4" thick plywood rings, drilled a 1" center hole with a spade bit, and then used a dremel tool to extend the hole to 32mm for the 29mm motor mount tube (which is 32mm outside diameter). The aft ring is currently gluing to the tube with wood glue.

I also started work on one of the Baby Berthas, which'll become the Nike Goon. I assembled the motor mount and modified the nose cone so that the streamer can fit inside, plus I put a little clay in the tip of the nose cone for stability.

I'll cut the fins tomorrow. They'll have TTW (through the wall) tabs that attach to the motor mount, and they'll be scale-sized Nike fins - exactly 1/10 the original size. That is; 2.34" root edge, 1.21" tip, and 2.16" wide. The original Nike boosters were 16.5" in diameter - exactly 10 times the 1.65" of the BT-60 of the Baby Bertha.

(Thank you Rockets of the World)

Monday, November 9, 2009

Up Late Again

I was up till nearly 2 doing homework last night, and I've still got a section outline for history and 5 calculus problems to do tonight. Wednesday will be a nice break - we have it off for Veteran's Day.

I got my order of rocketry stuff in the mail today. I ordered in last Wednesday night, so it took under 5 days. Very impressive, epecially since it was sent from Georgia, by snail mail.

The 38mm tubing is great - I'll only have to peel off one layer to get it to fit into the Baby Bertha.

See you tomorrow.

Sunday, November 8, 2009

More new motors from Aerotech and Cesaroni!

Today, Cesaroni announced the certification of 11 new reloads - 1 G, 1 I, 1 L, 6 M, and 3 N. These included two new propellants: C-star and Pink. C* is the characteristic velocity of a rocket motor, and accordingly C-star is a high-performance propellant with high metals content. The Pink propellant (some call it violet) was originally put forth by Paul Robinson. It's mostly a one-shot deal, for a woman certifying L3 on a bright pink rocket, but more will be certifed if the demand is there. It looks like this:


The certified motors were:
93Ns G80-SK-14A (CTI Pro29-2G) Skidmark
502Ns I120-IM-15A (CTI Pro54-1G) Imax
6118Ns M3100-WT-P (CTI Pro75-5G) White Thunder
6162Ns M1675-PK-P (CTI Pro75-5G) Pink (pictured above)
7545Ns M1590-CL-P (CTI Pro75-6G) Classic
5472Ns M2250-CS-P (CTI Pro75-4G) C-star
5342Ns M1560-WT-P (CTI Pro98-2G) White Thunder
9994Ns M3400-WT-P (CTI Pro98-4G) White Thunder
17631Ns N3800-BS-P (CTI Pro98-6GXL) Blue Streak
20146Ns N5800-CS-P (CTI Pro98-6GXL) C-Star
4701Ns L1290-SK-P (AMW 76-6000) Skidmark

I'm especially excited about the G80SK - the first MPR skidmark ever, and it's got under 62.5g of propellant (The 38-1G G69SK skid has 67g of propellant). It might be enough to get me to buy a CTI Pro29-2G case.

Full story on Rocketry Planet.

Not to be outdone, Aerotech is working on some new stuff of their own. There's the Loudmouth - looks like a White Lightning, sounds like a Sparky. A K345LM was flown at Plaster Blaster this weekend, as were a K375NW (Boost-sustain), J320WS (Super White Lightning), and the J99N endburner. Interestingly, the Loudmouth might 'possibly' make it to mid power. From Dick Stafford.

Saturday, November 7, 2009

Darn it

Internet out at my house = 3 months of posts every day broken. Oh well.

Thursday, November 5, 2009

Too much stuff

So you don't get a proper post. Because I have calculus and band homework, not to mention that I had work and jazz band tonight. I think we're the only jazz band for a while around that plays stuff like Stairway to Heaven and Enter Sandman.

Wednesday, November 4, 2009

Baffle

What I'm building for my pumpkin lofter, because a 2" tube would need a lot of wadding. I cut three 2" plywoods disks and drilled a 1/8" hole in the center of each, plus 4 3/8" holes in each. I'm now gluing them onto a 2" lenght of 1/8" dowel with the 3/8" holes staggered. That way, ejection gas can still flow through, but its speed is restricted by the staggered holes and disks, and it'll cool down and not fry the chute. Pictures eventually.

NARCON 2010

Linky link

It's March 13-14, 2010, in Worchester MA at Clark University, just an hour from where I live! The National Sport Launch (NSL) and NARAM (NAR Annual Meet) are never near me, so I guess having NARCON nearby two years in a row makes up for that.

I had an awesome time at NARCON 2009, so I'm definitely going to make it up there again. I have SATs on Saturday morning (the 13th), but I'll be able to drive up in the afternoon, and maybe even stay till Sunday.

Tuesday, November 3, 2009

Yet another motor order!

I've ordered a bunch of stuff from Hobbylinc, because their prices are cheap than anywhere else, and they don't charge extra for HAZMAT. For 82 bucks, including shipping, I got:

Practical stuff:
48" red and orange streamers. Good for rocket up to 3 ounces, like Machbusters. And they were 69¢ apiece.
Aerotech Interlock igniter clip, for dealign with those bloody Copperheads
1 bag of recovery wadding

Motors:
1/2A3-4T (4)
A10-3T (4)
B6-2 (3)
B6-4 (3)
B6-6 (3)
E23-8T: for my 29/40-120 case. Not a load I would normally choose since it's a Blue Thunder and 29mm E loads are usually expensive, but it was on sale for a price comparible to 24mm E loads.
G53-5FJ: for the same case. The exact load I wanted, and it was on sale. Perfect for the Nike-Apache sometime.

Goonies!
3 Baby Bertha kits. One will become the Nike Goon, another the Mach Goon, and another to be determined. Possibly a Saturn V goon?
48" of 38mm tubing. For the motor mount of the Mach goon, and then I'll have 43" left over for whatever.

There was still more stuff I was tempted to get. Their 24mm reloads are dirt cheap, as are 24/60 cases. As soon as Aerotech brings out more 24/60 loads, I'll snatch one up.

Blogging will be light for a few days, likely, as I'll be staying for a few days at a friend's house where getting the internet requires finding an unsecured wireless network, or treking back here after school.

Monday, November 2, 2009

More information on AT 24mm Gs

On this thread on TRF, Gary Rosenfield has released some more information about the possibility of 24mm Gs.

He confirms they'd be for 24/120 hardware, which would presumably be a 2-grain configuration. According to the 24/60 assembly drawing helpfully located in the 'resources' section on the Aerotech website, the fuel grains in the 24/60 case are 2.85" long, hence the 24/120 case would be 7.2 (=2.85+4.35) inches long, including the forward closure but not the aft closure.

He also confirms that they're working on other loads for the 24/60, including Redlines. This makes the EGE very very happy. The fact that he says loads, plural, prolly indicates a Black Jack and/or Blue Thunder load in the works.

He says that the single G load currently in the works will be a core-burner, because a C-slot grain would require either a thicker paper liner or phenolic liner, which would be more expensive. Also, for multi-grain motors, aligning the slots requires taping the grain together - an extra step that if forgotten would likely prevent proper ignition of the motor, certainly result in a strange thrust pattern with a much higher initial spike, and possibly cause a CATO.

He also mentions that because it would be a core burner, it would prolly be over 80N average thrust, making it a High Power motor instead of a Model Rocket motor, which may or may not be allowed at the Salem field I usually launch at.

Sunday, November 1, 2009

Randomness

Finally finished my outline for my thesis paper. 4 pages in size 11 font, 1887 words, and that's just the outline. The finished thesis paper will likely end up near 10 pages and 2500 words, bigger even than last year's thesis paper for English.

I didn't get a heck of a lot else done today due to the paper. I've got the SR-71 almost complete - I glued the aft section on, and that's currently drying. All that's left is the landing gear bay doors, and of course gluing the complete side pods to the main body.

I drilled the launch rod hole in the pyramid with a 3/8" spade bit. It still needs a few fillets and possibly painting for aesthetics, but structurally it's 100% ready to fly!

24mm Aerotech G Possible

According to this thread on TRF, Aerotech may eventually bring out 24mm RMS G motors.

One poster speculated that one, probably the first, might be simply two F35W grains together, which would make roughly a G70W with about 110Ns total impulse and 1.4s burn time. That would work well with delays on perhaps 5,8, and 11 seconds.

If they really do, it'd be interesting to see what the hardware looks like. 120Ns hardware would be about 6 to 7 inches long - too long for 24mm mounts with an engine block, but just fine for something like the Mozzie or 24mm saucer. I'm hoping the hardware would at least be compatible with one of the two current 24mm RMS sets, likely the 24/60 which has thicker walls designed for higher pressure, and is designed more like HPR hardware than the 24/40 set.

If they really do come out, then they'd prolly come out several loads as well with more loads for the 24/60 case, which I'm really hoping will eventually include Black Jack, White Lightning (F35W), Blue Thunder, and maybe even Redlines.

All is still speculation based on 9 words from Gary Rosenfield, but fun speculation indeed!

Saturday, October 31, 2009

Halloween!

Because for some reason, getting all dressed up just to hang out with friends is always worth it. We hung out, ate food, ate candy, and went MST3K on two movies. The first was Get Smart, which was very funny and absolutely awesome. The second was The Mummy, which wasn't quite as good but still definitely worth the time, especially when spent with awesome funny friends and a kick-ass (literally!) girlfriend.

Appropriately enough for Halloween, strange things happened. I got comments on my looks for the first time ever (apparently a black fedora and aviators look good on me), and I had to remove a very confused salamander from my basement when I went down there after the party.

The pyramid is effectively finished - All that's left is painting (maybe) and drilling the launch lug hole.

Friday, October 30, 2009

Ninjitsu, I has it

Since I'm actually going to a Halloween party for the first time in my life (hooray crazy friends!) I'm dressing up as a ninja. That means black pants, shirt, and tie; black ninja mask, black combat-style steel-toed boots, and weaponry. I'm working on ninja stars, but I already have a sword.

It's a fake katana with a 28" blade. I made it by taping two 36" x 1" window blinds together. I made a curved tip by cutting the material, reinforced it with wooden dowels taped together, and made a grip with masking and electrical tape. I painted the blade grey, and the widest part at the hilt gold, and the handle is black electrical tape.

I also made a scabbard out of wooden crown molding and masking tape. It slides onto my belt. Ninja pictures coming tomorrow.

Thursday, October 29, 2009

Band Concert!

Which means you don't get much of a post today, except me saying that I hate Reimann sums, and that the pyramid is going pretty well.

Also, the depressing facts that my US History book has no more than three paragraphs, in three places, about Apollo, and no pictures; and that I'm pretty horrible at drawing people like mandachan.

And that I'm such a nerd that a post on Bayourat Rocketry made me think of an article on the same topic which I read 5 months ago. And then promptly commented on.

A New Era Begins



Ares 1-X
Height: 322 ft
Liftoff Weight: 1800000 lb

At roughly 800000 pounds of APCP, at typical White Lightning energy density of ~400 Ns per pounds, that's roughly 320 000 000 Ns, or somewhere in the high AB to low AC impulse range.

This represents one of the first major steps back to the moon. Congratulations to NASA for a picture-perfect launch.

By the time the first second-generation lunar landings come in 2019 or 2020, I will be out of grad school, hopefully with a degree in Aerospace Engineering. I could be there.

Wednesday, October 28, 2009

Mandachan being awesome.

First, she's got yet another weekly update up on Drowning in Turtles. Her artwork just gets better and better. I wish I could draw like that, but my artistic ability is apparently limited to technical drawings.

Second, she has an awesome idea - doing a Questionable Content Music Tour. She'll listen to every band and artist mentioned in QC and blog about the music. That's an epic tour of indie rock, spanning over 1500 comics and perhaps 250 artists and bands. And she's even embedding youtube videos for your listening pleasure. The official announcement is here. I encourage you all to go take a look - it's pretty awesome!

Tuesday, October 27, 2009

Mach Goon

Here's a pretty crappy Paint rendition of the guts of the planned Mach Goon. The blue is the nose cone, which has a nose weight, eye hook, streamer, shock cord (kevlar), and kevlar heat shield inside it. The red with grey closures is the Aerotech 38/240 reload case. (The Cesaroni Pro38-2G casing is 1.17" longer and thus would not fit).

 

I don't have any 38/240 motors in TIRASP (to be corrected tomorrow), but on 29/240 motors, it simulated to Mach 1.3 and around 5000 to 8000 feet. Awesome performance for a Goony, and yet still plausible to recover if I put enough tracking powder in.

Since the recovery system is stored inside the hollow nose cone, almost the entire 7.5" long body tube can be used to hold the motor, which is 5.7" long not including the closures. Retention would simply be a few wraps of making tape. The ejection charge would be perhaps 1/10 of the supplied charge to simplify retention and recovery system needs; the remainder of the charge holder space would hold extra tracking powder.

I'm planning to buy 3 Baby Berthas soon with a motor order. One will be the Nike Goon, a second the Mach Goon, and the third yet unknown. It'll fly within a few months on a measly B6-4 for a test flight, and then on an H242T reload at NERRF.


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Monday, October 26, 2009

My Goonies

The Cloud Hopper:
 

The Pigasus:
 

All three together:
 

Besides the Nike Goon, I've got a few other Goony ideas bouncing around, including a Scissor-Wing Goon and one with a 5.5" long 38mm motor mount - just enough for a 38/240 case that could send it to Mach.

These are awesome felt cases that my mom made and painted for me. They protect my valuable hardware and make it easier to find.
 
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Pyramid Pictures and more!

Only a little bit is actually glued, but here's it taped together in an actual pyramid shape:
 
The 12" rulers are for scale.

The underside, showing the hole for the motor mount, plus the motor mount, mount tube, and 30" chute:
 

The 2" mailing tube that's destined for the pumpkin lofter, plus an end cap and 7 2" rings:
 

The partially assembled 1:48 SR-71:
 
The picture makes it look much more assembled than it really is. The front section and side pods are assmbled; the rest still needs gluing together.

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Aerotech 38mm spacers, 5 new reloads Certified!

Today Aerotech announced the certifcation of some cool stuff by Tripoli Motor Testing.

The first is the 38mm spacer system. No surprises there.

The next is the N3300R-P. It's a huge Redline with 14041 Ns total impulse for the 98/15360 hardware. The reload alone costs $798.99 !!! Thrust Curve

The next two are Karl E. Baumann signature motors. They use a version of Blue Thunder propellant that's got an Isp (specific impulse) of 224 seconds, one of the highest ever tested. There's the M1780NT for the 75/5120 casing (3.1s, 5783 Ns) and the M1845NT for the 98/7680 (4.4s, 8308 Ns). The NT indicates the modified Blue Thunder propellant. Prices are $239.99 for the M1780NT and $428.99 for the M1845NT. M1780NT thrust curve; M1845NT thrust curve

Next is the J99N, which I blogged about last month as being an in-testing motor. It's for the 54/852 case, not the 1280 Ns case as previously reported. It's got 945 Ns total impulse over a burn time of 10.3 seconds. It requires the use of a new 54mm aft closure that accomodates 29mm and 38mm nozzles ($39.99) and a forward bulkhead plug ($19.99). The new closure will be used soon on more new and redesigned 54mm reloads. Suggested price is $79.99; thrust curve here and assembly drawing here.

Finally comes a completely new motor case: the 38/1320 case. It's 23" long and designed to hold 11 grains; it'll retail for $89.99. There's also a new reload for it - the J510W. It's got 1162 Ns impulse and a burn time of 2.2 seconds; it strangely uses 6 long fuel grains in the 11 grain case. Suggested retail price is $79.99. thrust curve

I like these. 5 new HPR reloads, including a huge Redline, three high-impulse-blend motors, and a completely new motor case, closure, and spacer system, all released in one day. Props to Gary Rosenfield and the rest of the Aerotech team.

On Rocketry Planet

On TRF

Sunday, October 25, 2009

Blegh

Too tired to do a legit post.

I had an awesome time in Columbus. I love the city, and the Buckeyes kicked ass. I learned how to properly eat buffalo wings (hint: forget manners and cleanliness, and chow down!). We met up woth my dad's cousin, who he hadn't seen in 16 years. The cousin is a Civil War buff and had some impressive artifacts, including an officer's sword in very good condition, and a pistol from the time period which must have weighed 5 pounds!

Overall, an awesome time, and regular blogging resumes tomorrow with updates on construction and stuff like that.

Saturday, October 24, 2009

Thoughts on small composite motors

I know, I have lots of these 'thoughts on...' posts. I guess I just tend to have thoughts on a number of subjects in rocketry. This is somewhat of a filler while I'm on vacation.

While pondering the new Aerotech E20W during a few slow moments in history on Thursday, it occured to me that the E20, while certainly a great new motor, is not what I really wanted. Although it offers a few advantages over the E15, including higher thrust, the new molded case, and the FirstFire Jr. igniters, as well as the Econojet-style 2-motor packaging with a slightly lower price, it's not a huge paradigm shift over the E15. We already had 3 E motors with White Lightning propellant - the 24mm SU E15, the 24mm RMS E18, and the 29mm RMS E16. We didn't really need another 24mm SU motor.

All 6 Aerotech D motors (ignoring the rarely-used 24/20-40 and 32/60-100 cases for RC gliders), are either White Lightning or Blue Thunder. There's only one other propellant in the E size - the 24mm RMS E11J Black Jack, which doesn't even have enough thrust for a lot of models. F motors add the F12J, F22J and F23FJ (Fast Black Jack / Black Max) motors, but the only extra propellant in that range is the F27R Redline Econojet, which unfortunately is neither a 24mm nor reloadable. Only in the G range do we got more Redlines (G71R, G77R, G67R), Mojave Green (G76G, G78G), and Warp Nine (G339N and G69N; both, unfortunately, are 38mm motors), as well as the Cesaroni G69SK Skidmark.

What I would really like to see is some smaller motors with the more interesting propellants. Gary Rosenfield has stated that G motors are as small as they'll likely ever make Mojave Green propellants, and Warp Nine loads require some electronic deployment device as they can't use delay grains and ejection charges. That leaves, mostly, Redlines, which are okay with me, as I love the laser-red flame and loud roar. I'd like to see some smaller Redlines, at very least something like an F30R load for the 29/40-120 hobby case or 24/40 case, but preferrably a 24mm E Redline, either single-use (SU) or for the 24/40 motor case. I'd also like to see a smaller smoky motor; either a Black Jack (J) D load for the 18/20 or 24/40 cases, or even better an E-size Fast Black Jack load.

The ideal, of course, would be an 18mm Redline. All the awesomeness, in a tiny package!

However wonderful these conjectures would be if realized, I am still enormously happy with the variety of composite motors available in small sizes. Just a decade or two ago, the only D and E motors available were clunky blackpowder, and compositie motors were expensive, and mostly limited to white, black, and clear blue formulations. Today, you can buy composite motors from the D10W up through 150mm O motors, in almost a dozen different formulations. Even better, Aerotech has shown their devotion to us mid-power folks by introducing 2 new 24mm motors - the E20W and F32T - in under a year, improving the G80T, and introducing Mojave Green motors including the G76G and G78G. That's worthy of praise.

I hope you enjoyed this random tangent while I'm enjoying some FOOTBALL. I'll be back tomorrow with your regularly scheduled random daily geeky content.

Friday, October 23, 2009

Buckeyes!

I'm leaving today for a weekend in Ohio. I'll be flying this afternoon to Columbus, eating delicious food at BC Rooster's, watching the OSU Marching Band (The Best Damn Band In The Land) perform at the Skull Session, and of course, watch the Buckeyes kick some Minnesota ass. I'll be away from a computer from now morning until sometime sunday. Not to worry - I have a post automatically set to go up Saturday at noon for your enjoyment, and I'll be back Sunday.

Thursday, October 22, 2009

I am a Bloody Idiot.

Literally.

Yesterday, as I was cutting a bevel into a piece of plywood for the 29mm Pyramid, the exacto slipped, and of course managed to plunge itself into my left index finger. It didn't go too deep, and the cut is only about a quarter-inch long, but it bled pretty well for several minutes.

It's not the first time. I have a 1/2" long scar on my left thumb knuckle from cutting the tailcone on the Bullpup, a nick in the webbing between my left thumb and index finger from slipping while repairing the Transwing, and a small scar on my left thumb from who knows what. Plus numerous dents in my forehead from tripping, a dented chin from falling off my bed at age 3, a possibly broken wrist from last year, a burn on my left wrist from a campfire years ago, and a nice scar on my leg.

Strangely enough, I managed to keep my cool. I dropped the knife, grabbed the finger to slow the bleeding, and raced upstairs to the nearest parent. When I get injured, I seem to have several seconds or minutes of calm before panic and pain sets in. When I smashed my wrist, I managed to walk a quarter mile uphill before falling in a heap on the couch. When I scratched my leg on coral, I navigated a tricky rock ledge to get to the safety of a lagoon. When I burned my thumb on a soldering iron, I had the presence of mind to unplug it, put it on its stand, and drag my cousin upstairs while I got an icepack.

Then, today, I double-jammed and strained my right thumb. At least neither is essential for playing the trumpet.

Wednesday, October 21, 2009

New Aerotech E20W revealed!

As posted On their web site and on Facebook, where I found out about it, Aerotech has a new motor out: the E20W. It's a 24mm motor, the same size as Estes C11 and D12 and Aerotech E15 and E30 and 24/40 RMS at 70mm (2.75") long.

Vital Stats:
Impulse: 36 Ns
Burn time: 1.7s
Peak Thrust: 35.6 N
Delays: 4,7
Loaded weight: 49g
Propellant mass: 16.2g
Isp: 233 seconds
Grains: C-slot

It's the same molded one-piece phenolic casing as the F32T and G80T, with the built-in thrust ring and yellow delay holder. It comes in a two-pack, with 2 First Fire Jr. leaded igniters (hooray!), from $19.99. Certification is expected with 2 weeks or so, and shipments to retailer will be with a month.

A promotional flier is here and includes a time-thrust curve.

I'm not sure if it's intended to replace the E15W, or just complement it, but I like it. It's a better design with the new casing, and it's a perfect match for my Nike-Apache. I'll prolly order a 2-pack of E20-4Ws by the end of the year.

Interestingly, available from the same section of their website are thrust curves for two unreleased motors that might come soon: a 54/2560 K375NW Boost-sustain, and a D3-10T with a 5.4 second burn, prolly a single-use motor as no casing is mentioned. I hope they're released soon!

Tuesday, October 20, 2009

Thoughts on American Rocketry

Note: this was typed up on tuesday, but my internet connection asploded, so it's actually getting put up wednesday. Oh well.

While doing research yesterday on international model rocket motors, something occured to me. Although the United States is one of the most technologically advanced nations, and has a higher population than anyone except India (which is almost absent from the rocketry scene) and China, we are fairly low ranking in international competition, and regularly beat out by China and a variety of tiny Eastern European nations. There are a few US fliers like George Gassoway who are up there, but the US always overmatched, especially in stuff like scale modeling and innovative designs.

Why is this? I don't think it's necessarily because folks here have inferior education or skills, or that there's not enough rocketeers. I think it's mostly a consequence of high-power rocketry. Rocketeers, by nature, are a type a bunch that will always tackle the coolest and hardest problems out there. When you can get H loads for 20 bucks, and with a L3 certification you can fly up to O motors, HPR is clearly the way to go for the most fun. Rocketeers here are working on such crazy stuff as extreme altitude records, hitting space, exotic new propellants, and pushing the upper limits of amateur rocketry.

In places like Europe and China, high power motors are pretty much unavailable. They're lucky if they can get their hands on C and D motors at best. So, they devote their attention to other cool projects, like competition rocketry and scale modeling. Competition is mostly held with the small motors, and the rest of the world has better small motors - smaller sizes and such - so they get better practice, and heck, if all I had was 10-packs of B3s, I might learn to make some pretty high-flying stuff as well.

With scale competition, it's the same deal, plus that since they're forced to build smaller models, they get real good real quick at building highly detailed small models, which translates into absolutely perfect models. They've got years to devote to a few small models for world competition; most Americans want a selection that they can fly at local and regional launches every month or two.

So, is there any way to get back on top of scale and competition rocketry? Perhaps. There still are dedicated LPR folks like Trip Barber and George Gassoway who build amazing scale and competition models. But for me, I'll take big rockets any day of the week, and twice on Sunday. **clears throat** I love the smell of APCP in the morning. Smells like ... victory...

Monday, October 19, 2009

Coming Soon: The Nike Goon

 

To be made from a Baby Bertha kit. I love Goonies - an 8-dollar baby Bertha kit and some scrap balsa (and imagination) is all you need to make a rocket that flies on anything from an A8 to Cs and Ds, and that can handle 24mm motors if you change the mount.
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Plastic cement

Is not good for me. I spent about 40 minutes working with it in my unventilated basement building my SR-71 model. When I came up afterwards, I was shaky and clumsy, and my eyes were very dilated. I was still able to chat with a friend on the computer, but it wasn't easy. At my mom's suggestion, I rode my bike for a few minutes, and that certainly helped.

From now on I'll have the door open and only do a little at a time.

Unfortunately, I didn't have any time to work on rockets today because of homework. I did, however, do more simulations of my rockets on my calculator. Soon I'll have sim charts for every rocket I own.

German and Russian and Czech motors, oh my!

A while back I posted about Polish model rocket motors, which included A5, A15, B15, C15, and D15 motors.

Now, while looking at a German kit from Apogee, I got curious about the 25mm German motors mentioned, so I started doing a bit of research. Here's what I found:

A company called Weco seems to make most German rocket motors. (Germans are also about to import Estes and especially Quest motors). Sierra Fox Hobbies has a selection of Weco motors, including:
18mm: A8-3, B4-0 and -4, and C6-0 and -3, plus the well-known C2-P (Held 1000) - an unusual long-burn motor (5 second burn) intended for rocket gliders.
25mm: D7-0 and D7-3

Interestingly, the smaller motors come in 10-packs. 10 A8s are roughly $16.44 (11 €), 10 B4s $19.43 (13 €), and 10 C6s $22.42 (15 €). 3 D7s go for $14.95 (10 €)and apparently one Held 1000 goes for $22.42 (15 €)!

The VRO (Flemish Rocket Organization) has two non-American motors for sale: a D7-3, which they say is 23mm in diameter (and has a 12N average thrust and therefore is equivalent to a D12), and a Russian D10-4 which is 20mm x 85mm.

This page shows the Held 1000 (held translates as 'hero') as having 7Ns total impulse and 1.25N average thrust, plus shows its thrust curve.

Its big brother, the Held 5000 is a baby E8 (25Ns) with a 3-second burn time - very close to the Estes E9.

Finally, from Sierra Fox again, comes the Rapier motors from the Czech Republic. They include a 10-pack of A3-4s (exactly the same as Estes) for $23.91 (16 €), 5 B2-5 (15mm x 50mm) for $18.68 (12.50 €), 10 B3-5 (13mm x 58mm) for $34.38 (23 €).

They also carry a single Jetex motor, which are mini reloadable motors with thrust between 0.05 and 0.3 N and burn times between 5 and 30 seconds, intended for use with model planes. I hence refer you to the Jetex motor page. Interestingly, Jetex motors use Guadinine Nitrate (CH6N4O3), noted for its high (177 seconds) specific impulse and that its combustion produces only gases, not solid residue and smoke like the Ammonium Perchlorate and blackpowder of most model rockt and HPR motors.

Thanks to Sascha Grant for the tipoff to the VRO site.