Launch Report #45 Part 4: Others' flights

There weren't that many people at the launch - perhaps twenty at the most, with most of them the regular CATO crowd. That meant the range wasn't crazy, so I was able to take lots of pictures.

Here's Al Gloer's Fliskits Richter Recker on a cluster of three motors, mostly likely D12s:

And his Free Rocket #1 on an unidentified red motor:

Someone's Black Brant on a green motor, at full power but not even moving yet:

I wore my Jayne hat to the launch. Little did I know that I would not be the only one. It seems Al owns one too:

Launch Report #45 Part 3: Two-stage rockets

Since this was my first time flying rockets in seven months, I didn't try anything too fancy. No clusters, no gliders, and nothing requiring a tightly-packed parachute or other finicky recovery devices.

But what's life without a little adventure? So I did fly two two-staged rockets at CATO, both old favorites with a few flights under their belts. The first was the Jinx, a rocket I was given in 5th grade by a teacher. It's solid plastic and basically unbreakable and waterproof - the perfect rocket for a cold day with lots of water on the field.

This was its eighth flight since I started keeping records and there'd been a few before then; this was its third boosted flight. I used a B6-0 in a generic booster stage I built a while back and an A10-3 mini motor in the Jinx. They're on the left rod:

It flew beautifully. Staging was low enough to be in sight yet the Jinx flew fairly high. It came down near the pads but on a wet area of the field, and a CATO member with hip waders fetched it. The booster came down just 100 feet from the pads.


My final flight of the day was my twin saucers staged on a D12-0 / C6-0 combo. As always, they were stable even in wind and a good low and loud crowd-pleaser:

As with the previous video, this one is worth watching frame-by-frame. Consistent with simulations, the saucers oscillate (both back-and-forth and speed up/slow down) due to the large area and flexible nature,

Launch Report #45 Part 2: Happiness is a perfectly deployed parachute

Third flight of the day was the Mozzie on an F23-4 Black Jack that I've had since July 2009. It's a great motor - a baby F that still has enough kick to loft the Mozzie to a simulated altitude of 1065 feet. Due to the wind, the Mozzie arced over significantly weathercocked into the wind and reached a height of no more than 900 feet. But deployment was perfect and thanks to the weathercocking, it landed only 400 feet downwind of the pad.

A couple of the kids hanging around got to it before I did, which I don't normally like because I prefer to see the landing zone if a rocket was damaged on landing so I can prevent the mistake. But this landing was perfect - into the stream. Fortunately the paint suffered no damage, and the Mozzie will fly again.

Launch Report #44: CATO 173

(Yikes, almost six months since I last flew a rocket..)

I finally got out to a CATO launch on Saturday. I had math team practice beforehand (the depths of my nerdery are astounding, neh?) so I only had time to fly three rockets. Still, lots of fun.

First was the first flight of the MLAS. It's still not quite finished - needs some fillets and some paint - but enough so to fly. I put it up on a C6-3, and thanks to the extra nose weight I added it flew perfectly straight. One parachute got a bit melted, but there was no damage.

Second was the Multi-Goon on three B6-4s. Somehow, it didn't work right. I think that one igniter got pulled out slightly while I was wiring up the cluster, and it ignited late, causing the rocket to spin in midair immediately after leaving the launch rod.

Third was by Fliskits L-13 on a D13-4W White Lightning reload. The 18mm reloads have a lot of punch, and this one was no exception. Unfortunately, the L-13 wasn't quite stable. Just off the launch rod, it took a 90-degree left turn and heading for the northern horizon at about 30 feet altitude. Fortunately, it's a light and draggy rocket, so after the motor burned out it floated pretty gently back to earth. No causalities, and the only damage was a small scale detail (replaceable) which got knocked off by the launch rod.

Interestingly, these three flights now put me at a recorded total of just over 3,000 Newton-seconds of impulse burned.

Eight Birds with One Stone

I had possibly the most productive errand trip today. (Errands? Dang, I am getting old.)

I went to the bank. Boring, but entirely necessary.

I got Chinese food (Asian beef > American beef) and ate it with mandachan.

We planned our secret project.

I went to Staples and bought a new USB drive. I always keep a USB drive in my pocket (for transferring data, and to always have a portable version of Firefox and Tor), but my old one broke. This one is neat and retractable, so it won't break. It's 4 gigabytes - and cost me only eight dollars. That's five hundred megabytes per dollar. In 1993, the year I was born, a dollar bought you a 1.44 megabyte floppy disk.

Then, I went to Union Station in New London to pick up my ticket; I'm visiting BU next week. I get to ride the Acela; how cool is that?

I went to Lee' Toy and Hobby in Groton. I bought packs on B6-4, C6-3, and D12-5 motors, plus thick superglue for repairs.

I also bought materials for a small part of the secret project.

Then, I went to work.

And now I'm home, avoiding homework.

2010 Motor Usage

A copy of my sidebar gadget, before I blank it for 2011.

0	0	0	11	6	6	9	3	1	5	0
MMX	¼A	½A	A	B	C	D	E	F	G	H

Total of 46 motors on 33 flights - lots of clusters. Total impulse was 1208 Newton-seconds - equivalent to an 88.7% J.

Rocketry Todo

I've got quite a long build / repairs list.

REPAIR:

• Repair the broken fin on the Sudden Mach. It needs to be done perfectly to prevent the fin from rebreaking at speed, but it shouldn't be too difficult.
• Rebalance the 29mm Pyramid. This will be tricky; there needs to be enough forward mass to keep it stable on a baby H, while not making it too heavy.
• Repair or replace numerous old decals on the ARV Condor gliders

REPAINT:

• Primer and repaint the new forward section on the Orbital Transport
• Use steel wool to shine the primer, then fully paint the rebuilt Nell

BUILD:

• Estes Patriot: definite upgrade from original kit: definitely a baffle or payload section, possibly a motor upgrade or dual-deploy
• MLAS - build, stock except for a few picky things on the motor mount
• Buffalo: order extra BT-80 tubing, build for dual deploy

OTHER:

• Openrocket: simulate a number of rockets, including Nell, MLAS, and Patriot
• Rama: I need to decide what to do with Rama. Everything is falling apart - tube, motor mount, and fins. I could scrap it, or I rebuilt it, replacing almost every component.

FUTURE: My big project this year will be to get my Level 2 certification after I turn 18. I may use a 4" diameter Madcow kit, or Polecat Aerospace's 5.5" Mosquito. It'll be a lot of work, but a lot of fun, and it'll allow me to start (safely) working with experimental motors. A slightly smaller project will be Serenity. I intend to build a largish scale model of the spacecraft - an Firefly mid-bulk transport, class 03K64 - from the TV series Firefly and the movie Serenity. It'll be around two feet long, built from a jumbo Easter egg (for the ovoid trace compression block engine) with a 29mm mount and probably clear plastic fins.

CATO 167: Punkin Chunkin: Part 5

Here are a few pictures of Al Gloer's Darkstar Itty Bitty on an F30SS:

And some unknown rockets:

CATO 167: Punkin Chunkin: Part 2

Shortly after the flight of Svetlana, my folks showed up, bearing cameras. My second flight of the day was my pumpkin-lofting flight, the Great Punkin on a G53-7 FJ (Black Max) motor. Simulated altitude 890 feet. The booster had a 16 chute; the punkin had a 36" by 66 chute that I made out of a garbage bag.

It started out well:

But, the giant chute did not open, and instead of soaring, my punkin plummeted to the ground. It, amazingly, survived. My revenge was swift and tasty:

CATO 167: Punkin Chunkin: Part 1

CATO was on Sunday this month; Saturday was rather windy. And, I haven't had time to write about it till now. Pictures will come later tonight, or tomorrow.

My first flight was the Svetlana on an F35-8W - my first launch with my new 24/60 case. It simulates to 1192 feet on Openrocket, and that might be conservative. It zoomed off the pad - the 57 Newton-second (Ns) load packs a lot more punch than a 40 Ns E18 load. I drilled the nominally-8-second delay down to about 6 seconds, and it ejected just past apogee.

Since my old baffle was destroyed at NERRF, I opted to make a temporary one out of duct tape. Just a 10" long tube, made using a 29/240 case as a mandrel. I tapered one end to fit in the motor mount tube, and stuffed the other end in the nosecone. I packed the 12" chute as usual and sure enough, it deployed without being burnt. The duct tape was barely burnt. Fun fact: duct tape can take the heat of a blackpowder ejection charge.

Even with the small 12" chute, it drifted a lot. Everyone thought it was going to land in the woods... but nope, it touched down on the adjacent field. Easy to get to, and I even found someone else's nose cone on the way to get it.

Next: I have pictures!

Getting ready for Punkin Chunkin

I made a parachute from a garbage bag today. Huge friggin' chute. 36" by 66". It'll lower a 7 oz punkin at just 4 feet per second.

(And yes, it is 'punkin', not pumpkin. Only punkins get launched.)

I've also got the Nell ready for launch - added the launch lugs and shock cord. The final coat of paint can wait for after its first flight.

The Great Punkin - my half-assed punkin lofter, cobbled together last year out of two mailing tubes and some scrap wood - had aquired new decoration in preparation for its second flight tomorrow. It now has a zigzag black stripe around the yellowish body. To say I am pleased would be an understatement.

PUNKIN CHUNKIN IS (NOT) TOMORROW

It is going to be very windy tomorrow. Punkin Chunkin is delayed until Sunday. I have to wait another day before I get to launch punkins.

I AM SO VERY DISAPPOINTED, SO I AM TALKING IN ALL CAPS. IRONICALLY OF COURSE.

On the other hand, I actually have time to make a large parachute, and get my rockets ready. So it's not all bad, just frustrating.

The Little Monstrosity That Could

I've posted before about the Rokit.

It's made from a D12 motor casing, a scraped-up nose cone, and poor-quality balsa. It's liberally covered with masking tape. Its mis-spelled name is written on in magic marker.

It is... the ugliest rocket in the world.

Or, I thought so, until the end of August, when Al Gloer's 'Project Frankenrush' trounced me in the Ugliest Rocket competition. That eldritch abomination is made from the remains of three different rockets, and still has dirt on it from crashes.

But, Al bargained with Dave Mackiernan of Hot Rod Rockets for help with a different project of his. So, he had a kit ready to ship, and he graciously offered it to me as the second-place finisher.

Which means that as of last Thursday, I have a brand-new, just-released Buffalo kit ready to build. It looks to be high-quality and really, really cool. I'll build it immediately*.

* Immediately meaning, after my calculus midterm, math team meet, MIT interview, Marine Science field trip, and marching band rehearsal, plus normal classes and homework.

Launch Report #42: CATO 165

Today was an absolutely perfect day for flying. No wind, high clouds, no rain, no bothersome farmers, and a small turnout that meant no waiting for a pad to launch.

First flight was the Orbital Transport on a C6-3. Despite the lack of wind, it did a spontaneous left turn at about 30 feet of altitude and crashed about 200 feet away. As I turned to collect the wreckage, the ejection charge fired, leaving an eerie mini-mushroom cloud of smoke marking its position in the crash. Although the impact was at speed, the only damage is a crimp in the forward body tube and a single missing fin. The glider is undamaged, and repairs should not be terribly difficult.

Second flight was the SR-71 on an E18-4W reload. The Copperhead igniter burned but failed to start the motor, so I replaced it with a more reliable FirstFire Jr, and it lit perfectly the second time. Reasonably straight boost, and it twisted and glided after burnout as the giant aerodynamic surfaces took effect. The ejection charge failed to deploy the chute, but the big flapping plastic body prevented any damage. The 24mm body tube, however, came unglued during the flight and I will have to reattach it. Still, a far superior life for that old plastic model than not being rocket powered..

Third flight was the Transwing on a C6-3. Perfect boost to around 400 feet, separation at apogee, and a beautiful, slow, turning glide. 38 seconds. Probably the best flight anyone has ever gotten out of a Transwing. Its wingtips need realignment, though. Goes on the to-do list.

Fourth was the Heli-roc on an A10-3 mini motor. Nice boost to around 300 feet, and it spun down perfectly... upside down. No damage, and I had to run out (with permission) to retrieve it because it had fallen directly under the future flame path of a G106 Skidmark on the away pads. That would not have been pretty.

Fifth was the Buckeye IV, as part of Viperfest. Only three on this rack. I was the first off the pad.... and Al Gloer's remained firmly stationary. The ejection charges burned a hole in my kevlar chute protector, and the chute failed to deploy, but it was undamaged.

Sixth and final flight was the Multi-Goon on a cluster of 5 A10-3 motors. It was my first 5-motor cluster. Al Gloer was (jokingly) talking trash beforehand. Instead, it lifted off hot straight, and normal, and I knew instantly that I had 100% ignition. Chute deployed at apogee, for an absolutely perfect flight.

On the Workbench

I've got a lot of rocketry projects currently going on.

36" parachute: The lines were fried by the plume of a G64, then snapped by the vortices created by the fast-moving blunt object. They will be replaced.

Pyramid: Needs to be more stable, so that means nose weight. Going to change the motor mount a bit, so that the 29mm mount can possibly be swapped out for 38 or 54mm.

Nell: Needs to be finished. The thin tubes connecting everything are going to be ridiculously tricky.

A.R.V. Condor: Gliders need better glide-testing.

Rama: One of my refurbishment jobs. Going to replace the launch lug, rebuild and refinish the nose cone, and replace the motor mount. And maybe the fins. Heck, maybe I should just rebuild it entirely.

Bullpup: Going to redo the paint job. Strip it off, prime, paint, draw on markings.

MLAS: build.

No Crimp (13mm superroc): build.

Launch Report #41: CATO 164

Pretty good day at CATO, though it didn't get off to an auspicious start. Conflict with some grumpy old farmer, who supposedly has the rights to mow the town field we use.

First flight for me was Rama on a D13-4W reload. Nice fast flight with good chute deployment. However, due to the odd shape of the motor casing, it was sticking out the back of the rocket quite a bit, and it was not entirely stable during boost.

Second flight was the A.R.V. Condor on a B6-4. The gliders didn't glide very well - too nose-heavy - and all three parts fell into deep, thick grass. With the help of another CATO member and some of the Civil Air Patrol kids who came to the launch, I found the booster and both gliders. The life to fly another day.

Third flight was the 29mm Pyramid (of FLAMING DOOOOM!) on a G64. I taped a 36" parachute to the back and let it loose. Unfortunately, the quick-link came loose and swung into the thrust, diverting it to the side, and causing the parachute to get ripped off by the fast-moving air. Fortunately, it went in a high arc over and beyond the crowd, and landed in the field. Undamaged. That 3/16" bamboo lite-ply is gorram unbreakable.

Al Gloer disagrees. 2.125" packing tube = potential 54mm motor mount. We agreed that sometime, it'll take on the Aerotech I599N Warp Nine reload. That will likely rip it apart, but if it doesn't, it'll be spectacular. I won't even need a Level 2 certification (which I'm planning to get next year anyway).

Final flight was my Fliskits L-13 on a C6-3. Perfect flight - slow boost and perfect chute deployment. Jim Flis was there, and he took a picture of me with it. How awesome is that?

I Love Data

Not the android. Cool guy and all, but annoying after a while.

No, I'm talking about hard data. Facts. Information. Numbers. I love it. Call me a lifeless nerd (I do not deny), but some days I'd rather sit in the glow of my laptop screen and process data than do most anything else.

For example, my spreadsheet of data of all my rocket launches. It does everything. Automatically computes stats for every rocket and motor I've launches since October 2008. I'm still updating it to be more automatic, but it works nicely.

Ideally, it'll automatically compute everything. Add a new flight, it'll automatically add the impulse for the motor, update the number of flights for that particular rocket, add the reference number for that rocket, and update the number of flights with that particular motor. As of yet, all those things have to be updated manually.

But, once I finished sorting through all the errors today, I discovered some interesting stuff.

One odd bit is when I looked at the total impulse I've flown of each motor type. The two H165s from my certification last summer amount to 330 Newton-seconds, more than any other motor. 35 C6s equal 308 Ns, and 18 D12s make 302 Ns.

One more cluster flight with the Buckeye IV, though, and 4 more D12s will put it on top.

Two new Aerotech Motors!

Two new Aerotech motors; one reload and one single-use motor, were certified effective July 27.

The first is the second single-use motor to use their 24mm x 95mm (The same size as an Estes E9) molded case. It's an F30FJ (Fast Black Jack / Black Max propellant); it'll be available in 4, 6, and 8-second delays.

Its initial mass is 70 grams; 31.2g is propellant. Total impulse is 47 Ns - an 18% F - with a burn time of 1.51 seconds.

The other new motor is a G138T-14A load for the 29/40-120 hobby case. It's a slightly detuned version of the H load (which is undergoing slight modifications for certification). The stock delay is 14 seconds, adjustable by drilling, and the propellant is a high-solids, high-impulse Blue Thunder blend.

Initial mass is 148 grams, with 70 grams of propellant. The 138-Newton average thrust makes it a high-power load; the 70 grams of propellant require hazmat shipping. Impulse is 157 Ns, burn time is 1.14 seconds.

The EGE talks about what you're interested in.

Aside from the questions, there are clearly some thing you want to know about. I'll do my best to deliver:

July 10th: "Aerotech G71 vs G77":

The G71 and G77 are fairly similar motors. Both are Redline motors, with the awesome laser-red flame.

The G71 is a reload for the 29/40-120 hobby case. Its impulse is 107 Ns, at it contains 56.9 grams of propellant. It comes with delays of 4, 7, and 10 seconds.

The G77 actually comes in 2 slightly different styles. One is a reload for the 29/120 case (different from the 29/40-120). It is 105 Ns, with 58 grams of propellant and available delays of S (6 seconds) and M (10).

The other is a single-use motor, available in preassembled and loadable (different from reloadable) varieties. It contains 58.1 grams of propellant which generate 102.9 Ns of total impulse; available delays are 4, 7, and 10.

The bottom line: If you have the 29/40-120 hobby case, use the G71R reload.
If you have the 29/120 case, use the G77R reload.
If you have neither, use the G77R single-use motor. Choose the loadable variety if you want to save money and don't mind spending a few minutes building the motor.

July 12th: "best glue for ttw fin fillets mid power high power hpr rocketry":

Are you using fiberglass? If so, use epoxy.
Are you using carbon fiber? If so, use special high-temperature epoxy for carbon fiber.

If not, it depends on the application. For most uses, wood glue is excellent. It bonds excellently to paper / cardboard and all varieties of wood. It's incredibly strong, safe, and easy to use. It's cheap, sands well, and you can spread it into fillets with your fingers. It's slow to dry, though.

For attaching plastic, fiberglass, carbon fiber, metal, Blue Tube, or Quantum tube, epoxy will work better. It dries quickly and attaches almost everything. But, it'll stick to you, and it can cause allergies, so use *nitrile* (not latex) gloves.

A good compromise for larger rockets that need a lot of strength may be epoxy clay. It sets up rock hard, gives you plenty of time to precisely shape your fillets, and attaches anything. But it's expensive, and too much will be heavy.

July 12th: "blue thunder propellant formula":

Blue Thunder is a high-solids blend that burns very efficiently, with little smoke or colored flame. This indicates that it's almost pure ammonium perchlorate / aluminium blend, with few additives. I know very little about motor making; this site may be of help.

UPDATE: Thanks to Ken Kzak:

Blue Thunder is a high-solids blend that's mostly ammonium perchlorate and binders (PBAN and HTPB). Wikipedia gives one common recipe for high-performance, low-smoke motors as around 80% AP, 18% binder, and 2% metal. For Blue Thunder, that metal might be aluminium, magnesium, or copper.

July 13th: "rocksim file for madcow 2.6 patriot high powered rocket":

Madcow are awesome folk; I highly recommend their kits. On their page for the 2.6" fiberglass Patriot is a convenient link to the Rocksim file.

July 29th: "wisdom is knowing that you'll be an idiot in the future which qc comic":

Number Nine Hundred Seventy-six.

For the future, Ohnorobot is extremely useful, and searches over 100,000 panels of over 1700 comics.

The EGE answers your questions!

As I've mentioned before, I have Google Analytics code on this blog. It's very neat, because I can find how you're finding the blog, and what you're looking for in it.

Interestingly, some of you have gotten here by googling questions. Well, your questions are now getting answered.

From July 26th: "can i split a 6 grain cesaroni reload kit into 2 3grain reloads"

No, that's not possible. Each reload kit only comes with one nozzle and one set of forward components (delay, ejection charge, etc). If you took three grain out of a reload kit, you would only have three grains, and not a second complete propellant kit.

From July 10th: "how many ounces can a e30-4 model rocket lift?"

There's a convenient trick for this: The 5-to-1 rule. A motor should provide 5 Newtons of average thrust for every Newton the rocket weighs (4.45 N = 1 pound). For an E30 which generates 30N average thrust, The rocket should weigh no more than 6N at liftoff. That's about 1.3 pounds, or 21 ounces.

Now, the E30 has a higher thrust of around 45N at liftoff, and 5:1 is a bit conservative. If you're flying a very stable rocket in no wind off a long launch rod, you could maybe get a 32 oz (2 pound) rocket off the pad. But that's not guaranteed.

From July 16th: "lufthansa tour flight stopped from takeoff from cleveland hopkins airport because two guys were jokingly saying "hijack" to one another?g"

I don't even want to know. You're on your own here.

From July 8th: "wildman blackhawk or?"

Or what? The Blackhawk is an excellent kit, by the way.