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...