Tuesday, March 31, 2009

Mobius Electronics and Artificial Languages

I've discovered quite possibly the coolest electronic components ever (except for LEDs): möbius components. By having the current run around the surface of a möbius strip, resistors and capacitors with no inherent inductance can be made - ideal for high-frequency applications, where the inductance (electromagnet-ity) of a component would change the circuit considerably.

Wikipedia article here, Time article from 1964 here, patent for Mobius Capacitor here, and collection of articles on otherwise crackpot site here. No information anywhere, though, to indicate that anyone's ever put one into use.

I've also decided to learn a little Esperanto, to learn a little about language, lot confuse the hell out of my spanish teacher, and to learn profanities in a new language!

Sunday, March 29, 2009

Mush

Up to the end of H class on my motor chart. 174 so far.

Started the Nantucket Sound.

The clementine crate glider is no more. First test glide shattered it.

No tennis practice tomorrow, and I've got study (with mandachan and another friend), so I'll do more building and blogging tomorrow.

I mow have 7 followers (mandachan stop complaining, it's a joke setup). I feel like 2 1/3 Christs!

Saturday, March 28, 2009

Launch Report #28

Today was a rather auspicious launch. I fired my first composite and reloabable motor, had my first sucess with a Copperhead, plus a sucessful flight test of my new nylon chutes. I also proved my machbuster to be stable and workable.

First came Mach My Day on an A8-3. It flew straight and fast off the pad, ejected just past, and came down safely about 100 feet from the pad. Next flight: D21-7.

Second came the GBU-24 Paveway III on an A8-3. Although it's a recommended motor for the rocket, it only went up around 120 feet and ejected at about 80. Fortunately, the 13" nylon chute deployed quickly and it cam down safely with only a small body tube dent. I don't think these nylon chutes have quite as much drag as plastic chutes, athough the larger ones seem to glide and generate lift, so for that size I might actually need the 18" chute.

Third was the Glider 2 on a B6-2. It wobbled a lot under power and seperated just after burnout, for a 15-second glide nonetheless. I'm thinking of adding a wire glider-retention mechanism that Trip Barber showed at NARCON.

Fourth was the Deltie Thunder on a D12. It was marked with D12-3, but as I suspected from the clay cap being nearer the end, it was actually a D12-7, and it ejected 3 feet off the ground. No real damage, although the glider neeeds more reinforcement. I'm gonna write a letter to Estes - they're known for being good about giving refunds for malfunctioning motors, and their faulty motor damn near killed a 30-dollar rocket. If the glider didn't already have CA reinforcemnt due to minor glide testing crashes, or if it hadn't ejected above ground, or if the ground was hard, then the glider would have been splintered balsa. I've filed an NAR Mess form for it. Oddly enough, the other two motors from the pack all performed fine with 3-second delays. Fortunately, the 1/4" rod pushed 8" deep into the ground provided a good solid launch rod, and sticking my other rods into the ground have it bracing against the wind. I also managed to place my leads so that neither glider I flew today tangled, even though both had large protruding surfaces.

My fifth flight was much better. It was my 24mm saucer on a D15-4 24/40 Blue Thunder reload. It ttok a few seconds for my low-current system to fire the Copperhead, which demands 3 amps, but when it fired the rocket rose fast and loud with very little smoke to around 120 feet. I ejected right at ground level; I wonder if it's ok to leave the ejection charge out for saucers for no ejection. The motor was easily twuce as loud an an Estes D12 - very impressive. For Es and Fs I'll extend my igniter leads to their full 45' length. I'm thinking I'll buy E18W reloads next rather than E28Ts - the Blue Thunder is nice, but I want the big white flame and smoke of White Lightning for other flights. i've also decided I need an aft closure wrench - tightening it really hurt! It rather stunk after flight, so I threw the spent parts out in a plastic bag then immediately cleaned it to minimize the smell. Pictures maybe coming later today (it's 2:42 am right now).


Since September: 125 motors on 102 flights, 629 Ns (96.85 I) total (11 Ns - an A plus a C or any D - puts it into J range); 5.04 Ns (0.8% C) per motor and 6.17 Ns (23% C) per flight.

Massive Randonmess

Massive updtae post to make up for several hectic days in a row:
1) Lord Gavin now has glow-in-the-dark paint on the shoulder of its nose cone, top of its bulkhead, and fin edges, Second coat coming tomorrow. No ideas yet for the rest of the color scheme.

2) Deltie Thunder built and test glided. It's got a 1;5 or better glide ratio, but the balsa body is weak and I've had to fix it twice. I built the pod with 3/16" and 1/4" lugs. For the first flight at least, I'll use my 6' quarter-inch rod stuck into the ground, because with the glider sitting on the blast deflector or ground, the lugs are over 2 feet up the rod, and it needs 2 feet minimum of travel on the rod for stability. Next comes first flight on a D12-3 or D15-4.

2a) I think I'll scratch-build a mini-deltie-thunder at about half scale for use with my current small pop pod, cause I've got plenty of balsa and I don't wanna hafta buy a Deltie B kit.

3) I'm going to place an order soon for about 25 motors, including some E28 reloads, plus an aft closure wrench for my reload casing. When loaded, it's almost impossible to close it without the wrench.

4) I'm starting work on the Darling of Death, the 24mm clementine crate (Darling brand) boost glider. It's going to be a biplane with roughly 3" by 12" wings. The box is made or crappy 3/16" or so 3-ply wood, but it'll take the kick of a D at least.

5) My computer is currently geting fixed by a techie friend of my dad. Yay!

6) A little bit of bragging: I placed first among underclassman yesterday for the regional high school math league I belong to, meaning I get an automatic spot on the CT ARML (a national high school math competiton) team.

7)I started tennis on Monday, and theorretically it'll last several hours after school every weekday, so till the end of May you'll see less afternoon posts and more concentrated around 7 am and 11 pm and on rainy days and weekends. I played 3 challenge matches today and won them all, so I'm on the upper end of JV.

8) Congrats to Mandachan for making our school's JV softball team! She's worked hard and we're all rather proud of her, so you really should go over to her blog and leave a comment and congratulate her.

9) Apparently Estes has patented a new Potassium Chloride-based propellant called Vulcanite EB-75 that they may use for some motors. It's a very exciting possibility, as it's got twice the power of blackpowder, meaning possibilities of sub-62.5 gram F motors, full E motors that can be shipped non-hazmat, 10.5mm competition motors that outperform even the Czech Delta motors, C motors with just 1/4 ox of propellant, new B14-type motors, etc. It's able to be packed like blackpowder rather than cast like APCP, which means that existing Estes 'Mabel' machines could pack it and it might, unlike APCP, be suitable for booster motors. Imagine E30-0 or F50-0 boosters. Awesome for saucers. However, unlike BP, it would be suitable for reloadable motors. Read about it from Duck Stafford here, on YORF here, and from the patent applcation here.

10)Uhhh... there was something else... but I can't remember now... sooo... sleepy....

Tuesday, March 24, 2009

2 Things

1: I've now got completed 13", 18", 20", and 24" nylon chutes. Dark green nylon, thick nylon shroud lines (8 each ; all are octagonal), and expert stitching by my mom. I've tested all in my yard, and they all unfold well even in cold weather, have hgh drag, don't drift too much, and glide somewhat, which shows that they're producing lift - good for longer duration flights and softer landings.

The 13" chute will fit in BT-55, the 18" chutes in BT-60, and the 24" chute in BT-70, or maybe BT-200 ( in SpaceShipOne). I won't use the 24" chute in SS1, though - the last one is still up in a tree. These are really high-quality chutes - better looking, stronger, more durable, and more likely to open than plastic, and I got six for 2 bucks of nylon fabric and a buck fifty of string.

2: I'm up to complete data for up to the H148. 145 motors in 11 impulse classes, with 7 data columns (manufacturer, length, diameter, SU vs reload hardware, total impulse, propellant mass, and propellant type (including the different Aerotech formulations)), plus 5 delay columns (booster, short, medium, and long delays, plus plugged), plus a note on whether I've used it, merely bought it, or can use it with my reload hardware. It's coming to a published Google doc soon.

Monday, March 23, 2009

Parachutes

I designed the patterns last night during half of Cold Case and all of The Unit. I cut them out today; my mom'll do the edge sewing tomorrow hopefully. By pure chance, I will have 13", 18", 20", and 24" chutes - 13mm, 18mm, 20mm, and 24mm are all model rocket motor sizes.

Bad Astronomy Mystery

Phil Plait of the Bad Astronomy Blog has a mysterious secret. He's also asked everyone one the internats to link to him for the big announcement (coming at an indeterminate later time) so there you go.

Sunday, March 22, 2009

Updates

1) My laptop is still out of commission, so I'm still using my parents' desktop. I hate not having Chrome, but the much faster internet (pdfs open in a fifth the time) is a big plus compared to my slow wireless. I've got all my documents backed up, fortunately. However, my blogging is still limited to when parents are gone, asleep, or otherwise occupied (like by loud NCAA games).

2) My motor list is now complete thru all 1/8A to G motors. That's still only about a third of all the motors (up to O) certified by the NAR, CAR, and TRA, but now every single LPR motor - 121 of them - is in my database. I'll put it up, published, on Google Docs when I'm done. It takes about 1 minute per motor for batches of 20-40, using the NAR list, TRA/CAR list, Thrustcurve.org, and the list in the Jan/Feb Sport Rocketry, plus google for occasional fact-checking.

3) I'm planning to put a full list of links for all my useful published stuff on the side bar. Look for it later today.

4) I didn't get to go test my new reload casing today (in my 24mm saucer) due to the wind. Grr.

5) Building: I've got the launch lug (3/16") on Lord Gavin, but it still needs paint scheme ideas. I built the entire Deltie Thunder glider with CA today. It glides great - about a 5:1 or better glide ratio. It's absolutely huge - and very heavy at around 2 or 3 ounces, but i's not dense and has huge area, so it comes down pretty light. It needed a lot of clay - 80% of the provided stuff for balance plus 10% for side-to-side balance. It's currently getting fillets on the joints for extra strength - I also put the vertical stab stiffeners on for future use with E and F reloads. Next comes chute and pod assembly, plus helping my mom make chutes from the nylon I bought.

Saturday, March 21, 2009

Lord Gavin

The contest for the name is over, won by Sacha Grant, but the paint scheme contest is still on.
 
The tan is balsa, the orange is orange plastic, the grey-outlined tubing is the clear plastic payload bay, and the black-outlined tubes are plain carboard tubing.
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Thoughts on my new reload case

I really like my new Rouse-Tech 24/40 reload case. It's quite the piece of (expensive) engineering and the versatility of 8 different flavors of motor with several dealy options each really appeals to me. I like getting to load my own motor; it makes me feel mature and powerful putting the puzzle together. However, two drawbacks annoy me a little bit.

First, the casing is only usable one or twice per launch. You can reload the motor in all of 2 minutes, but it has to be cleaned, greased, etc between launches, which is hard to do in the field. Second, and worse, the D15-4 reload kit I bough wasn't quite perfect. The delay grain, grain spacer, and liner tube were all two tight. I very carefully solved the problem by peeling the superthin layer of glassine off all of them. That made them fit much better (the liner tube is perfect, the grain spacer and delay grain tight put okay) without compromising the interity of the motor. I really wish I didn't have to do that just to made the motor ready to assemble, though.

NARCON

was amazing. I've never been to any sort of major geek conference before, so this was a really cool experience. It was in Wethersfield, only an hour away, in their nice but mazelike high school. (It takes 3 turns just to get into the vafeteria and the vendors, and 4 more to get to the lectures.) There were about a dozen vendors there, including Aerotech - with a 1/2 scale Patriot and ~10x upscale Der Red Max, Balsa Machining Services, Semroc, Fliskits, and several smaller vendors.

I bought the Nantucket Sound - a 24mm flying lighthouse - from Fliskits, won a Skyripper t-shirt as a door prize, and bought a yard (36" x 45") of thin nylon for chutes at a nearby discount fabric store. I bought tons of stuff from BMS - 2 of the new F32-4Ts (I was the first consumer in the world to buy an F32-4 and the third to get an F32 at all), a 29mm balsa nose cone, 6 3/16" launch lugs, a 24/40 reload case, a 3-pack of D15-4 reloads, and an Edmonds Deltie Thunder. The Deltie Thunder is a huge 24mm boost glider with an open delta wing. And I mean HUGE. The glider is about 30" long and 32" wide; the pod is nearly 2 feet long. It'll rock on D12-3s and D15-4s; E11-3J and F12-3J reloads will be possible.

I attended two lectures. The firt was on Beginning High Power Rocketry by David Applegate of METRA. He's a L3 flier with a ton of knowledge about fiberglassing, dual deployment, avionics bays, and other cool geeky stuff. I'm even more encouraged to do my L1 cert at METRA in August, especially since I saw a few 29/180 casings there and one'll definitely fit the Mozzie.

The second was on competition boost gliders by Trip Barber, NAR President. He had some absolutely amazing boost glider that're half the weight of my best with 10 times the glider ratio. He also showed us some amazing Czech Delta A2 motors used in FAI (International) Competition. They're 10mm in diameter, about 30 long, and have a full 2.5Ns of impulse because they use a composite propellant with twice the energy density of blackpowder. Unfortunately, it costs ten thousand bucks for a permit to bring a live one here (his were spent casings), so the only ones in the US at all are a small stock owned by the NAR.

Overall, NARCON was great. I learned a lot, bought a lot, and met people like Trip Barber, Nick Esselman (aka EMRR), Jim Flis, and Gary Rosenfield, owner and motor genius of Aerotech / RCS. Gary, notably, said that the impetus for the F32 was the phase-outs of the old F21W due to bad-quality phenolic casings from China that made CATOS too likely.

Friday, March 20, 2009

New Aerotech F32T at NARCON

Aerotech is introducing their first new 24mm SU motor since 2001 at NARCON, where I'm heading tomorrow. It's an F32T with a modified Blue Thunder propellant with a specific impulse of 225 seconds. It's 95mm (3.75") long - the same size and weight (65g initial with 25.8g of propellant) as an Estes E9, but with twice the total impulse (56.9 Ns). It's available in delays of 4,6, and 8 seconds and its burn time is 1.6 seconds. I'm gonna pick one up tomorrow for my 24m saucer.
The full story from Rocketry Planet

Thursday, March 19, 2009

Cool Article

True "Homeland Security" means letting our kids know they can, and must, experiment, discover, and, sometimes blow things up." - Dan Dubno

Once again, Dick Stafford brings epic win, in this case an article about how doing stupid stuff like pyromania and dangerous chemistry is often the beginning of a good scientist. I've stuck to mostly tame stuff, but I've had my moments, like nearly lighting the house on fire with my homemade ignition system, crashed a 3-stage monster, launched spinning stufff in my yard, even in the middle of a snowstorm, attempted to launch legos, launched a potato, burnt flammable acetone, and much much more.

New rocket

Boredom, spare parts, and plenty of CA do not a good mix make. At least not yesterday, cause now I've got a whole nother rocket jest sittin' around. It's a 24mm payload carrier made from 29mm tubing. It's about 32" long overall, making it my second-longest rocket. It consists of 23 3/4" of 29mm tubing (13" plus 10.75" plus a tube coupler), a 24mm universal motor mount (no motor hook or thrust ring, just 1/2" of tube sticking out the back to tape the motor to, 27" of 1/4" elastic shock cord, a 4.75" clear payload tube (3.75" free) with plastic bulkhead, and a homemade 27mm (the payload tube is a bit smaller than the body) balsa nose cone.

It'll use C11-3, D12-3, E9-4/6, and 24/40 reloads and use a 12" or 16" chute depending on the payload mass and the altitude. The 27mm by 95mm payload bay is a bit small, but plenty bit enough to fit stuff like a small beeper or strobe light, a small glow stick for night launches, or the new Quest altimeter. The How High Altimeter fit inside a 20mm diameter tube (hating on us 18mm minimum diameter types) and can go from 50' to 7000' AGL. It only takes a full data sample once per second, but even that is only a maximum altitude error of just 4 feet. It's only $45, so I'm seriously thinking of gettting one. I could do fun things like compute the CD (drag coefficient) of the rocket by comparing simulations to actual altitude.

Open contest to name the new rocket and suggest a paint scheme. The winner gets me to plug what ever link they want, subject to my filtering for NFSW stuff, dangerous sites, and anything BAFTE.

Tuesday, March 17, 2009

Yet more computer problems

My laptop is once again a semi-functional black box of mystery. Both IE and Chrome seem to have corrupt files in their directories, and it took three tries to get the disk checker to accept me as an administrator on my own computer to boot it up. I managed to get the few files I didn't already have backed up - including a complete spreadsheet of all NRA / TRA / CAR certified motors - about 550 when finished; I've got 69 (MMX thru F) done. The data I've got include motor code, diameter, length, single use / RMS casing used, total impulse, propellant mass, and available delays. I'll publish it on Google Docs soon.
So right now, you readers won't notice too much except for a few less posts, plus me stressing out a bit more. Posts will come mainly around 7am, 3pm, and 11pm when I'm up and my folks aren't using their desktop.

Odd...

So I'm reading this BABlog post about how sodium will become transparent at pressures of 3 million atmospheres. The title of the post is 'How do we know he didn't invent the thing', a reference to the Scene in Star Trek IV: The Voyage Home where Scotty shares the formula for transparent aluminum with a company in exchange for material to build a holding tank for whales. When I searched the quote, a link came up to an Air Force Article discussing ALON, transparent aluminum-oxygen-nitrogen (Al-O-N, ALON) ceramic armor materials. Turns out that the BA post links to the Wikipedia article on transparent aluminum, which links to the ALON article, which links to the Air Force article. Google somehow connected those two seeming unrelated articles. Weird, but cool.

Monday, March 16, 2009

Model Rocket Purity Test

Found this while researching active guidance for my last post. It's a very funny (and dangerous) test of just how mych of a model rocket pyro you are. I only fit a few: I've broken two parts on the safety code: flying without a blast deflector and flying C engines in a too-small space, both while flying monocopters in my yard, I sometimes intentionally fly rocket without chutes and streamers (only cause they're backsliding gliders of lightweight), and I have delusions of grandeur.
Some are truly funny, like Have you and an a gang enemy sucessfully engaged in a drive-by model rocket bombing? Yo? and Does your latest warship carry a surplus CIWS? (Close-in Weapon System). (CIWS are computer-controlled autotargeting machine gun / cannons carried by warships to shoot down close-in aircraft, missiles, and even RPGs).

NAR / TRA Legal Victory!

Since every other rocketry blog on the planet has done a celebratory post, I might as well too...
Basically, the NAR and TRA (poor Triploi, always listed behind the NAR) have officially won. BAFTE (Bureau of Alcohol, Tobacco, Firearms, and Explosives) was declared to be 'arbitrary and capricious' by Reggie B. Walton, US Circuit Court Judge. Although it's not 100 percent final - BAFTE may still file appeals, or try to sneakily rewrite the laws, it's a huge victory for scientific facts over a government agency that, although certainly interested in national security, went way overboard.

In this case, this scientific truth is that high-power rocket motors are not explosive - they are designed to fire a rocket forward, not to explode, and that they're not usable for weaponry. A common M67 hand grenade, for example, has 6.5 oz - 184g - of explosives, which detonate in well under a hundreth of a second. An Aerotech 38mm H73J has 185.6g of APCP, which burns in 2.6s, over 250 times the burn time. The M67 frag grenade has a casualty radius of 15 meters, or about 49 feet. Even with the approximately 1% CATO rate of reloads like the H73, they can legally be ignited from 50 feet away, which would be risking nasty injuries with an M67.

HPR motors are also not useful for homemade weaponry, like say a homemade anti-aircraft missile - they're just not powerful enough. Almost no one in model and high-power rocketry is experimenting with active guidance systems, and those that exist are probably rudimentary at best. The reason that model and high-power rockets work so well is that they're light and can work on smallish motors and guided only by static fins. They simply don't have the power to lift warheads and active guidance systems. Take the common Stinger shoulder-launched missile, for example. It's 1.52m (5 feet) long and weighs about 23 pounds. It has an effective range of over 15000 feet, which means it packs probably an L motor, if not more. A model rocket of that size would have about a 29mm motor mount, maybe an F or G maximum, and reach maybe 3000 feet and far less than the Mach 2.2 of the Stinger. The Stinger is responsible for at least 270 confirmed aircraft kills; model rockets are responsible for none.

This decision means that LEUPs (Low Explosive User Permits) and explosive storage magazines will likely no longer be required for at least smaller HPR motors, plus that nasty 62.5g propellant limit will be gone, which means lower prices and more availability for F and G motors.

Sunday, March 15, 2009

Standard Disclaimer

This is the disclaimer from a site that I'm using for directions for my 5x5x5 Rubix cube. I assume it's still the copyright of Matt Munroe, the author, but you be the judge:
This product is meant for educational purposes only. Any resemblance to real persons, living or dead, is unintentional and purely coincidental. We have sent the forms which seem right for you. List at least two alternate dates. Batteries not included. Record additional transactions on back of previous stub. Objects in mirror may be closer than they appear. Shading within a garment may occur. Employees and their families are not eligible. You must be present to win. Do not write below this line. No shoes, no shirt, no service. An equal opportunity employer. The best safeguard, second only to abstinence, is the use of a condom. Reproduction strictly prohibited. Subject to CAB approval. No anchovies unless otherwise specified. Not responsible for typographical errors. Driver does not carry cash. Post office will not deliver without postage. Text may contain material some readers may find objectionable, Parental guidance is advised. Prerecorded for this time zone. Times approximate....
Read the full disclaimer

(The cube directions are pretty good too.)

Launch Report #27

It was warm enough for SHORT SLEEVES today! There were 5-15 mph winds, although they didn't affect my flights too much. Once again, Mandachan came with me, and a few kids playing softball nearby also watched a bit.

I used my new complete 12V relay-tripped system; it worked very well and fired all the Estes igniters within half a second. With 30 feet of main wire plus 15 for the Estes controller used to trigger it, I've got close to 40 feet of separation, enough for definitely E flights and probably Fs if I'm careful.

First came the 1x Mosquito on a 1/2A3-4T. It boosted high and fast, visible at its peak only by the smoke trail, and ejected just past at around 400-500 feet up. The motor casing came down just 20 feet from us, while the rocket fell invisibly 150 feet away, although my dad found it later. I think the 1/4A3-4T will be a better motor for this rocket.

Next came the Mandachan on a 1/2A3-4T. It boosted straight to around 150 to 200 feet, arced over into the wind, and ejected about a second past. The streamer came out and it landed softly.

Third was the Cloud Hopper on an A8-3. It arced over a bit into the wind and made it to maybe 150 or so. It ejected just past and one of the two streamers came out; it landed softly without damage. The two smallish streamers work far better than a parachute for a rocket of this light weight and large (bad for chutes) diameter.
Fourth came the rebuilt Frankenstein, with a longer (24" overall length) body, no engine hook for better alignment, and Alpha III fins. I used the two booster stages from my Comanche-3 to hold the D12-0 and C6-0 boosters. The D12 burned long and straight and it staged at around 250 feet. After staging, it went into a flat spin for the burn time of the two C6s, then fell and ejected at around 150 feet. All parts landed undamaged, except for some burns on the 18mm booster, within 30 feet of each other. I won't try triple-staging the Frankenstein again, but D12-0 / C6-7 (or maybe -5) and C6-0 / C6 combos are possible, as is a composite D21-4.

Fifth came Mozzie on a D12-3. It's a great motor for this rocket. It arced over a bit into the wind (those big fins weathercock a lot) and ejected just past at around 250 feet. The nose popped off.... and the chute never came out. Despite the chute being wrapped too tight to open (it's not burnt though), the rocket bounced on the soft ground and is undamaged. The body tube is short and tough to fit the chute in; I'll have to figure out the best way to wrap it so it'll still open.

Finally, I launched the Mandachan on an A10-3T. It boosted very straight to around 400 feet and landed undamaged despite the streamer only partially deploying.

I then tried to launch my Mach My Day on its D21-7, but the Copperhead burned without igniting the motor. I'll have to buy a 3-pack of preferred First Fire Jrs, with leads rather than the fragile foil strip of the Copperhead, with my order of 24/40 RMS hardware.

I'm up to 584.06 Ns (84.5% I) on 102 flights on 120 motors. 4.87 Ns (94.7% B) per motor and 5.73 (14.5% C) per flight.

Saturday, March 14, 2009

BAFTE Court Case Update

The NAR and TRA released a joint statement today about their court case with BAFTE (Bureau of Rednecks Alcohol, Tobacco, Firearms, and Explosives), which a while ago decided to overstep its authority and classify HPR motors as explosive... even though they're not. The text of the statement:
Today Judge Reggie Walton, presiding in our case before the US District Court, heard arguments from both legal counsel for NAR/TRA and the BATFE. At the conclusion of the hearing, Judge Walton stated that he was inclined to agree with our position. While this is extremely encouraging, there will be no formal written ruling until April, and BATFE may attempt to file additional information before that date. We expect that this ruling will provide some form of relief from the current regulatory situation.

We thank our members for their continued patience and their generous financial support. We will provide members with immediate status reports as this case reaches its conclusion.

Ken Good
TRA President

Trip Barber
NAR President

Basically, both sides presented their cases to the judge, and the judge tended to side with us rocketeers (yay checks and balances in action), but we won't know for sure till April. This is good news for the NAR and TRA; they've presented a solid case that BAFTE went way overboard, and they've pretty much won all the smll battles along the way. If BAFTE is forced to reverse their stance, then HPR motors, and actually all motors with over 62.5 g of propellant will be far easier to buy and use, plus be legal to store without a LEUP (Low Explosives User Permit) which is costly, difficult, and invasive (full background check and everything) toobtain. Plus, I suspect it might even make shipping HPR motors cheaper. This would make it easier for me to get my certification; I could buy the motor whenever, assemble it at home, and fly it for my cert when it's convenient rather than having to make arrangements ahead to buy the motor, then be forced to fly it on the same day.

Speaking of getting my cert, I'm looking into flying my Mozzie on a 29mm H128W-S (6-second delay), which'll fit in the smaller 29mm motor mount and get it only up to around 3000 feet - easily recoverable. The H128 is the famed 'baby H'; its small size and low impulse - barely into the H range - make it ideal for situations like this. The posibility exists that I'll do it between August 14th and 16th at NERRF at Pine Island, NY - the closest (3.5 hrs) HPR field. CATO used to use a field in Sterling for HPR launches, but it's currently being converted to sod and not usuable although the owners stated that CATO might be welcome in the future if they go back to corn.

I have Projectile Envy

My Machbuster, 7g unloaded and about 30 loaded, will hit Mach 1.1 or so, about 400 meters per second. If it hit something soft, like inconcievably a human, It would penetrate a bit but probably destroy itself before it could give someone more than a nasty bruise and maybe a small amount of internal bleeding, maybe breaking something fragile, but not fatal. After all, it's going twice as fast as a bullet and has about 4 times the kinetic energy, but bigger and draggier and made of crumplable materials.

Compare that to a 7g Lexan block fired at 7000 mps, about 17.5 times as fast and with about 300 times the kinetic energy of the empty MMD, 150 times the burnt motor + rocket, and 75 times the loaded mass, into an aluminium block:

That's impressive. It was a test for part of the SDI, aka 'Star Wars,' in a project invloving kinetic weapons.
The embiggened image is here and the info page here.

Thursday, March 12, 2009

It's my Birthday!

I have now been on the earth for an integer number of earth revolutions. That's right. I am no longer a nibble. This geek needs 5, countem 5 bits now.
I gots some awesome presents. I got One Two Three Infinity by George Gamow from my sister - He's like martin Gardner, except for science. Witty and informative articles on a variety of scientific and mathematical subjects. I'll tell more as I read it.

I got a 5x5x5 Rubix Cube (I can solve a standard 3x3x3 in under 2 minutes); my goal for this one is 5.

I also got Rockets of the World by Peter Always, the world's foremost expert on scale modeling. It's got some 200 sounding rockets, satelite boosters, human launch vechiles, and a few military rockets (like the V2) from all around the world from 1926 (Goddard) to rockets from as recently as 1995, ranging in size from the 1.3m Polish RASKO-2 to the 363 ft (111) Staurn V and the 343 ft (105m) Russian N1 moon rocket. It's got great scale drawings, color schemes, histories, and photos for almost every rocket, plus two really cool features: a 1:600 scale comparison of every single rocket in one two-page spread at the end, and NAR motor designations for about half the rockets.

The smallest listed are probably the 7-motor cluster of M12000s in the NASA Iris sounding rocket plus a few Ls in a cluster on some other rocket. Most amateur-size rockets either don't have full motor data available or else were packed with huge motors to send them into space or the upper atmosphere. The smallest one could easily be made into nice 1:1 models for L1 or L2 cert; you'd certainly have a unique rocket and a well-flying one - the smallest sounding rockets usually have the simple lines of the larger ones.

The biggest motors are the 5 AC6700000 (AC is 8 times the power of a Z) on the Saturn V, or maybe the not-grouped shuttle SRBS, but the most powerful is the Russian N1 moon rocket. 30 AA1510000 motors, equal to about a single AF, or about twice the Saturn V's first stage thrust total. I expect to build several nice scale models from the book.

I'm also gonna buy myself a 24/40 RMS casing and some E28-4 reloads. Fun with the Mozzie at CATO and my 24mm saucer anywhere. That thing'l rock, really loud, on a high-trust E. Or, dear deity, something like an F24 reload. That'll wake the neighbors up.

Tuesday, March 10, 2009

New Ignition System, Part I

I currently have a pair of Estes Electron Beam 6V launch controllers. They work just fine for Estes igniters; the batteries last around 50 to 100 launches. However, they don't generate enough current to fire a hot-wire igniter (like the Quest MMX igniters) reliably, and they simply can't fire Copperheads. (Copperheads are Aerotech's igniters for small composite and reloadable motors, like the D21 for my machbuster and the 24/40 motors I plan to get. Quest's new Q2G2 igniters can ignite a few composites, but estes igniters cannot).
I'm building a new ignition system based a few guidelines:
  • Must be triggered by a standard Electron Beam Controller.

  • Must not require modifying my existing equipment

  • Must be cheap and use available components.

  • Must have at least 30 feet of wire so I can fire up to F motors safely.

  • Must provide 12V at several amps with 2 6V lantern batteries attached.

My new system is very simple. It consists of 2 lantern batteries, a 6V relay, and 30+ feet of wire, plus alligator clips to attach to motors. The relay coil is triggered by a standard launch controller. The 6V relay is the only special part; it costs about 3-5 dollars from catalogues or Radioshack, but I took mine off an old circuit board. That's what I call electronics recycling. The only drawback is that the test current thru the light bulb is enough to trigger the relay; I'll have to add about a 10Ω or 100Ω resistor in series with the coil. I tested the coil in its little box tonight; tomorrow I'll figure out the wires and clips. Because the wire I found in the junk box is 4-core wire, it'll be very easy to do clustering. That's another place where the extra current and voltage comes in handy.
I'll also draw up a simple circuit diagram.

Minor building Stuff

1) The Mandachan is now officially finished. I drilled 3 holes for the vented gap staging (as if Estes is ever gonna rerelease the A10-0Ts. ha. ha. ha.), put in the engine blocks in both stages, obtained some thin elastic from my parts box, and now the shock cord mount is finishing gluing. The streamer is green and about 2" x 12". As long as I don't fly Uranium (or Hassium) in the payload bay it'll be fine, and the smallish streamer will fit well in the thin tube. Any suggestions for payloads?

2) I found the 1x Mosquito in the neighbor's yard. All 3 fins needed reglued, but it's back in the fleet. I still gotta make a new 6mm adapter though.

3) Everything from Saturday's launch is repaired.

Sunday, March 8, 2009

Four random things

First, I hereby command all of you to go to your local library and check out a book, either dead tree or recycled electrons, by Nelson Demille. Any of his are fine, but I recommend his John Corey novels, starting with Plum Island, which in its premise scares me cause the real Plum Island, home of biological research by the Department of Agriculture, is about 12 miles from my house as the proverbial crow theoretically flies. In chronological order are Plum Island, The Lion's Game, Night Fall (about TWA Flight 800) and Wild Fire. They're about John Corey, ex-NYPD, currently on the ATTF (fictional Anti-Terrorism Task Force) and complete badass. Like Harry Callahan, but funnier and removed from the 70s. And I mean funny - the novels are mostly in the first person and Corey makes a politically incorrect joke about once a paragraph. My favorite, oh-so-stereotypical and wrong but still funny as hell:

Q: What's a moderate Arab?
A: A terrorist who's out of ammunition.


Second: I found out tonight that salmon mixed with melted butter and garlic is really good, as are cold pancakes. Yummy.

Third, after using Chrome for the last 6 months, I've gotten really used to the in-browser spell check and favorites bar across the top. (I'm currently using IE on my parents' desktop while my laptop awaits being looked at.) Get on it, Microsloth. Chrome is faster, shinier, open source, and has features like the two mentioned above, plus a better-looking interface and incognito browsing, which prevents websites from showing in your search history or putting cookies on your computer. Plus, IE needs a separate security suite; with a bit of care, Chrome doesn't. Unless Microsoft wakes up and really improves IE, their browser business is down the tubes. Pun intentional.

Finally, this is my 250th post. That's almost one per day over the last 9 months; starting in November I've averaged over one a day and rarely skipped more than 2 or 3 consecutive days. At my present rate, I'll have over 365 posts on June 10, the The Amateur Geek's first anniversary.

Skiing!

I got to go skiing today up at Wachussett Mountain in Massachusetts. The conditions weren't great - slush; thick, nonpowdery snow; thin base coat; closed trails, etc, but it was fun and we got 18 runs in. I really love skiing; there's just something about being (somewhat) out in peaceful nature and feeling free to go fast and jump and whatnot. I figure the only comparable experiences would be weightlessness and maybe alpine hiking; I've done the latter and hope to experience the former.

Saturday, March 7, 2009

Launch Report #26

It was 60° F out today, and they snow was all melted - how could I not go fly rockets, especially with Mandachan available for an audience?

First came the WAC-Corporal on a 1/2A3-4T. It boosted straightish but slightly unstable to about 200 feet. The nose cone came off but not the streamer, so it came a bit fast but undamaged. Failure of recovery devices was pretty common today.

Second was the maiden flight of the Nuclear Mosquito on a B6-4. It's a great motor for it, although a C6-5 would of course be better. The chute melted abit (it's still usable, though) and didn't deploy, but there was no damage other than a few grass stains.

Third was the repaired SpaceShipOne on a B6-2, the first time I flew it on less than a C. It flew straight with maybe 4 complete rolls before ejection, but the chute only half deployed and it came down a hair fast. One boom shattered despite the soft ground - it snapped at the aft end of the main wing-fins, then split lengthwise. I repaired it with superglue and wood glue, but unless it gets perfect deployments it'll have one more flight, maybe 2, before it retires. I'll probably use a D21-4 composite motor to give it a nice sendout. Either that, or I gotta start using larger chutes, and we all know how that went....

Fourth was the Astron Invader on the third B6-2 in a row. It looped twice near ground level, then continued upwards to about 200 feet before ejecting. It glided - upsde down - for about 300 linear feet, maybe 15 to 20 seconds. This is a great motor for it - A8-3s and B6-4s have too long of delays, and with C6-3s it's unstable for most of its flight, while with the B6-2 it becomes stable within half a second and flies fairly well.

Next came the Orbital Transport on a C6-3. This is the only motor I'll use with it normally; it boosted high and fast but with a nasty case of pitch-roll coupling, where the period of it spinning matches the period of its back-and-forth wobbling and it spins conically. It stayed in control, though, and ejected just past apogee. The booster's chute failed to deploy, but it landed safely with no damage. The glider glided for at least 400 linear feet in maybe 30 seconds; it flipped, circled, and did a few mild aerobatics in the light wind before flipping over at landing and snapping off the attachment dowel. An easy fix. Despite the pitch-roll coupling, it was a cool flight and 30 seconds is a respectable C glide time, especially with a complex, heavy booster and a glider designed for looks, not glide ratio. I had very good luck with gliders today.

Next came an ungodly monster: Vampire (D12-0) staged to Hi (C6-0) staged to Frankenstein (C6-7). It was designed to go to a half mile high, eject a full load of tracking powder, and sacrifice Frankenstein to the rocket gods forever. However, with the heavy 3-motor combination, a fairly short rocket, and the smallish fins of Vampire, it wasn't quite stable with all 3 stages. It went sideways at about a 25° angle from the horizon. The Vampire dropped off about 250 feet from the pad about 150 feet in the air; the C6-0 igited and it became stable. the Vampire dropped safely to the ground, It was lucky. The stable but awry and falling rocket simply could not maintain its heading under the thrust of the C6; it crashed audibly into a football field (fortunately empty) about 450 feet away from the pad. This is the scene:

A close-up of the impact site. The purple fins of Frankenstein are plastic and slide safely out of their holder; the balsa fins of Hi do not.

The Hi booster was a total loss. The nose cone (found 120 feet away from the impact site), fin unit, shock cord, and fin unit of Frankenstein are intact and will fly again with the same purpose - and bigger fins. The C6-7 did not ignite and will fly again in Frankenstein 2. Due to the hard impact (CATO risk) and the clay cap being partially broken, I won't fly it in anything else.

Finally, I flew the WAC Corporal again on an A3-4T. It was less stable this time; it arced over significantly. The motor was ejected; the nose cone came barely off but the streamer stayed in and it core-sampled. No serious damage; it'll fly again.

So - two sucessful gliders, 3 chute failures, 2 streamer failures, and one epic crash. I'm up to 526.36 Ns (64.5% I), with 111 motors used on 96 flights on 44 different rockets and boosters. 4.74Ns (89.7% B) per motor and 5.48Ns (9.7% C) per flight. I can't believe I'm already 2/3 of the way to a J motor.

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Superdense Elements

The heaviest natural elements are of course Osmium and Iridium, with densities around 22.6. Osmium beats iridium 22.610 to 22.560 according to Wikipedia, but I recall reading older books where they weren't known to enough sig figs (significant figures) to be sure. (Then again, my 1842 astronomy book says the asteroids have huge, thick atmospheres, that meteors are static electricity, and intelligent life lives on the sun - no joke - so maybe newer books are better). That means that a 1-cube of either weighs three-quarters of an ounce - 22 times the same amount of water. Lead is only half as dense as the two at 11.342g/cm3, and iron a third at 7.8.

However, some of the transuranium elements may be even denser. According to this handy list, Seaborgium and Meitnerium are estimated to have desnities of 35, Bohrium 37, Dubnium 39, and Hassium an incredible 41, or almost 1.5 ounces per cc. Of course, the total yield ever of Hassium is a couple hundred atoms, but still.

Of course, inside a Neutron Star the densities might reach over 1014 g/cc, and at 10-44 seconds (the Planck time) after the Big Bang, the universe's density was around 1093, an utterly incomprehenisble number.

Also, random fact: Bismuth-209 (Bi209) has a half life of over 1019 years, making it technically (but not for practical purposes) radioactive, and that that was predicted before it was detected.

Friday, March 6, 2009

Mandachan and Nuclear Mosquito

The newly painted Nuclear Mosquito, ready for flight (hopefully tomorrow):
 
The Mandachan in all its glory. Note the 2 sections of launch lug (for better stability for such a long rocket while on the pad), red-to-yellow spray paint transition, Mandachan signature, and the stupid balsa nose cone that doesn't hold paint well.
 
All the parts: 4" nose cone, 9" payload bay, 18" main body, and 4" booster stage, for use if the A10-0Ts come out again.
 

As always, click to embiggen.
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Crayon Rocket Pics

It looks like just a crayon....
 
But it's really a fully functional rocket! It's got three clear plastic fins, a 2-part launch lug, a kevlar and string shock cord, a tiny streamer, and a realistic nose cone made out of a carved dowel and a bit of red pen.
 
It's made up of 12 parts: 1/4" launch lug / body tube, 3 fins, thrust ring, kevlar, string, streamer, dowel, pen bit, and 2 bits of launch lug.
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More computer troubles

It's acting up again, so light blogging for a while. sorry. Hopefully it'll be better soon.
Update on Saturday morning: I've found that all the crashes involved a .kml (Google Earth) file, and all happened after I downloaded a lot, like in Gearth or trying to download Itunes 8. I've uninstalled Google Earth and I'll see if there's any way I can safely wipe my computer of .kml files.

Thursday, March 5, 2009

Launch Report #25

Two launches in a row with Mandachan around... it's great having an audience.

After painting the Mandachan (pics coming soon), we launched a few of my tiny rockets outside.

First came IT on a MMX. Perfect flight to 60 feet, bounced off a branch, yaddie yada yada. Sticking skinny Estes igniters is a very reliable ignition method for MMX -way better than the bare wire igniters Quest provides.
Second came my 13mm saucer on a 1/2A3-4T. The hole in the saucer which served as the launch lug ripped and the saucer skittered around the pad, bending the rod and making Mandachan laugh at loud.

Third came the Whirling Twirling Tornado of Fire and Death and Doom (my 18mm monocopter) on a C6-0. It immediately buried itself 6" deep in the snow, leaching smoke through the snow. it actually looked pretty cool.
Finally came my Pen rocket on a MMX. It shot off the pad quick, ejected before apogee, kept going up to around 180 feet, and then came back down through the trees without damage. Its first perfect flight yet.

Wednesday, March 4, 2009

Nuclear Mosquito

My 3x Mosquito upscale is complete. I did a pretty good job with the paint job even in the 25° F weather. It's an almost stock Baby Bertha except for the fins; however, I put a snap swivel on the nose cone for easier parachute attachment / detachment and of course made the classic Mosquito fins. (The pattern for them was made from the copy of the Mozzie fins, downscaled to 60% on a photocopier.

 It'll fly on A8-3, B4-4s, B6-4s, C6-5s, and maybe the occasional composite D for fun. It's overstable due to the big, light, swept-back fins and since it's light but draggy it'll be very tolerant of mis-chosen delays, just as the Mozzie is. (Light and draggy means that it'll fall slower after apogee and thus be moving slower on a too-long delay). Patience, young grasshoppers, pictures are coming soon. And yup, it's named after Calvin and Hobbes: the island where they annually camp is named by Calvin as "Itchy Island, home of the nuclear mosquitos".

The World's Craziest Cult

The House of David was a Jewish (?) cult formed in 1903 in Michigan. They were your standard apocalyptic cult: no meat, shaving, haircuts, or sex. Of course, their dear leader got in some personal troubles, the cult went downhill (there's still a few dozen left), etc etc. Oh, and they played baseball. Well. They fielded several semipro teams that toured the country playing exhibition games. Satchel Paige even played for them once - in disguise.

Obligatory Wikipedia Link

Monday, March 2, 2009

Crayon rocket

Made from a 1/4" launch lug tube. It's got a crayon-shaped nose cone, 3 clear plastic fins, and 2 short bits of launch lug carefully blended in. I hand-drew the stripes, Crayola logo, and 'red' descriptor with a fine-point marker. It'll fly to about 150 feet on a MMX motor; pictures coming soon.

I've also got the fins glued and fillets drying, plus the motor mount assembled and glued in, on my 3x Mosquito. If I don't find the 1x version, then I'll make a new one.

Mandachan has commissioned a rocket in her honor. It'll be a 13mm superroc about 30" (762mm)long, suitable for 1/2A and A competition, with a 5-caliber ogive balsa nose cone, 3 small fins, and mid-body deployment and a long (~8" or even ~16") payload tube. She'll do the designing of the fins and color scheme.

Sunday, March 1, 2009

Snow!

We got maybe a quarter inch this morning... just enough to make the ground soggy all day. The snow started around 9:30, and by 10:10, with less than a centimeter on the ground, school in my district is already canceled for tomorrow. No wonder - we're supposed to get about 6-9" tonight and 3-5" tomorrow all day.
9:30 pm: 0"
10:10 pm: .3"
11:06 pm: .8"
12:55 am: 1.5"

Launch Report #24

I got to launch between the morning snow showers and tonight's snowstorm (school is already canceled for tomorrow), and even with Mandachan of Divided Loyalty fame attending. I launch 5 rockets of 5 flights on 5 motors, with fairly good success: 1 glider, 1 streamer, and 1 chute deployed with 1streamer failing to deploy.
First came the Screaming Yellow Zonker! on a B6-4; it went high and fast and made a nice spiral thop-thop-thop; its streamer failed to deploy and one fin had to be reglued.

Next came the SpaceBusII on a 1/2A3-4T; it went about 200 feet high and ejected just at apogee. Both sections came down fast but safely; the fin/motor section lost a fin which I reglued.

Next came Glider 2 on a B6-2; this photo is right at ignition:

It flew well but the glider came off at burnout. I've since modified the glider hook to fix that. The pod continued upward and ejected at apogee. The streamer deployed perfectly even in the 36°F weather. meanwhile, the glider settled into a wind-induced tight turn / wide turn cycle; it went about 300 feet in 15 seconds of gliding from about 120 feet up; it made it up to about 150 after separation before turning downward.
Next came my crowd-pleasing 24mm and 18mm saucers on a D12-0 / C6-0 load. Here's it at liftoff...

And the smoke trail...

As always, it pulsated under thrust, making a thop-thop-thop sound that got the attention of a jogger almost 500 feet away. The 18mm saucer staged funny and went sideways then downwards under thrust. Fortunately, it ejected about 50 feet up and both sections came down safely.
Mozzie on the pad, below. Even though it has 1/4" lugs, they're spaced far enough apart to use a 3/16" rod. It needs at least a 4' rod for D12s (and D15s and E15s), so the Estes maxi-rod won't be good, but it works just fine on a normal Estes Porta-Pad (although an E Pad on Aerotech mantis would be better). I'd so use no less than a 6-foot 1/4" rod for an E9 or E11 reload.

At ignition on a D12-3

And at full thrust a quarter-second later:

It was my first 100% perfect flight in a while; it boosted slow and loud (slow enough to scare me into thinking it'd arc over and crash, but it went perfectly straight), ejected right at apogee, waited a heart-stopping moment to open, and then:

A perfect chute deployment; it landed within 100' of the pad perfectly undamaged. Gotta love that big purple chute and nearly 8 feet of shock cord.

Me, Mandachan, Mozzie, and the box o' rockets.
I've flown 85 flights on 99 motors for 465.14 Ns (45.1% I), for 4.7 (87.9% B) per motor and 5.47 (9.4% C) per flight.
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Building update

I've cut the fins for my 3x (BT-60-based) Mosquito, to be made from a Baby Bertha kit. It'll fly on 18mm motors and have the stock 12" chute. It's the perfect size of mosquito - big enough to be easy to track, but small enough to use 18mm motors and fly on smaller fields.

I'm making a 1:1 scale crayon out of 1/4" launch lug and clear plastic fin material. The nose cone is a carved section of 1/4" dowel with a bit of pen casing over it to keep it on right.

I found the pod pod (intact) and glider (crushed) of Hummingbird - the glider glided almost 100 feet - but the Mosquito is still MIA and will soon be buried under a foot of snow. Ya gotta love CT weather.