that is all.
Golf Alltrack S DSG | Rad City ebike | Kona Rove allroad bike | Kona Manomano MTB
Outdoors stuff: biking, skiing, climbing, anything snow, geology
Photo stuff: Canon 6D, 16-35mm/300mm lenses, landscapes mostly (and some cars and cities)
Aerospace stuff: High power rockets, RC planes
Best posts made by spacekraken
Hyphen wagon club check in
Can't let the trucks be the only ones to have the fun here
Who's got a longroof here!?
For the purposes here, you have a wagon if:
-it has glass over the rear cargo area
-it's based on a sedan or hatch but with an extended roofline
-it has a seat height and roofline lower than a typical CUV (I'll let the outback slide here, lifted wagons are good)
An Oppo’s guide to the world of high power rocketry
Or, how to burn money even faster than most vehicular hobbies
So following a couple rocket posts here and interest from some oppos, I thought I’d write up a little guide for how to get into this really fun hobby. Here’s a very rough guide, broken down into sections:
Categorization: all* hobby rockets flown at club launches follow guidelines by either the National Association of Rocketry (NAR) or Tripoli Rocketry Association (TRA). There are, broadly speaking, a LOT of clubs around and it’s by far the best way to get started-they tend to have some experienced mentors and flying sites since once you progress to bigger motors FAA approval is needed to launch. A quick google ought to find clubs near you-it might be a few hours drive since they tend to be far from cities and airports, but that’s hardly an issue for oppos. Rocket motors are grouped by letter, A through O (and even past O). Each letter represents a doubling in total impulse/power-An A motor gets a maximum of 2.5 newton-seconds, a B is 5, a C is 10… and a G, the largest you can fly without certification, is up to 160. Anything past a G motor is “high power” and requires a license to fly. More on certification later…
Rocket design: Rockets are typically built out of cardboard and wood, fiberglass, carbon fiber, or various canvas composite or phenolic materials. They can range from 6mm diameter to well over a meter in diameter, but generally low power rockets are constructed with 13mm to 98mm airframes and high power range from 29mm up, usually at least 60mm. Generally speaking, “sport flying” rockets use a motor of a smaller diameter than the airframe (for example, a 38mm diameter motor housed in a 98mm diameter rocket), but performance rockets shooting for the highest altitude possible use tubing the same diameter as the OD of the motor to fit as much motor as possible for maximum speed or altitude. Fins are either surface-mounted with alignment jigs or “thru-the-wall” between the outer tube and motor tube for added strength, and layups of fiberglass or carbon fiber are often employed for added strength.
Fiberglass (red/black), cardboard/plywood, and canvas composite (brown) rockets
Recovery: almost every rocket past a C motor has some form of active recovery-either a parachute or streamer. On smaller rockets, these are usually deployed by a small black powder charge at the end of the motor-motors are sold with various time delays so that after a boost + coast period the charge fires, pressurizes the rockets airframe, and separates the rocket in a way to deploy the parachute. Larger rockets and more complex rockets typically use a barometer/accelerometer based electronics system to fire small explosive charges instead of a time delay-this is much more accurate and means the parachute deploys right at apogee when the rocket is moving at the slowest part of the flight. Quite commonly with higher flights, a form of “dual deploy” is used with a small parachute or streamer deployed at apogee for a fast descent from altitude, followed by a large parachute deployed at low altitude (either a second explosive charge or a tether release) to slow the landing speed dramatically. This allows for a ~60-120 ft/s descent from high altitudes like 10,000’ or more, followed by a slow, safe 20 ft/s descent for the last couple hundred feet to land the rocket to fly again. All rockets flown at club launches are required to have active recovery of some sort as the last thing anyone wants is a rocket coming in ballistic over a crowd of people…
G motor 98mm rocket landing
Certifications: Both NAR and TRA follow the guidelines below for “rocket licenses” effectively:
-0 to 160 newton seconds or A-G motors: no license required
-160-640 newton seconds or H and I motors: Level 1 cert
-640-5120 newton seconds or J, K, L motors: Level 2 cert
-5120 and up newton seconds: Level 3 cert
Level 1 is quite easy: fly a rocket on an H or I motor and recover it in one piece with a certified supervisor. Level 2 requires a written knowledge test followed by a safe J, K, or L flight. Level 3 requires written documentation of the build of the rocket, redundant electronic deployment systems, and 1 or 2 certified officials following every major step of the process. While there’s not a delay required between certifications, most folks (myself very much included) will highly recommend getting plenty of flights in at a given skill level before advancing to more powerful and more dangerous rockets. Fly your L1, practice with electronic deployment for 10+ flights, then think about how you want to do L2 (electronic deployment? motor deploy? how high?), then get a bunch of K and L flights in before considering L3.
"Sparky" L motor at dusk
Motors: Most motors are commercial, Cesaroni Technology and Loki Research are the two brands I fly for larger stuff usually. Motors come in reloadable (metal casing, sometimes reusable metal nozzles) and single use forms. Both effectively are tubes stuffed with propellant-black powder for some small motors like A-E, ammonium perchlorate composite (see, Shuttle SRBs) for larger ones. Typical prices are $10 for a three pack of A/B/C motors, $20 for a G motor, and $100-150 for a K motor to give some sense of scale. TRA L2 and up members can also make their own motors-it’s quite the process but VERY fun. Hybrid motors also exist using a tank of oxidizer and rubber/plastic fuel, but that’s well outside my wheelhouse.
My L1, on an H, many moons ago
Other stuff: GPS tracking is commonly used on higher flights and I 100% recommend it, as are bright metallic streamers for visibility. Also, have fun! This is an awesome hobby, and I hope this guide helps some folks a bit who might be interested. Feel free to @ me with project ideas or questions-I’ve been doing this since age 6
Couple more photos...
A K flight on a newer build of the same design as my L1 rocket.
My L2 rocket on a "pink" K motor
My L2 rocket on a J motor
"odd-rocks" are very popular
Sometimes things don't go as planned... this is what happens when your airframe fails at 500mph. Part of the experience!?
Latest posts made by spacekraken
RE: Poll: best kind of automatic gear shifter
@spacekraken column shift is the best cause then you can have a bench seat and sit close to your date at the drive in movies
RE: Why People Buy Crossovers - Explained (OP Update)
@ita97 Gravel bikes are lifted wagons, not crossovers
My serious argument for this is that lifting a car/fitting bigger tires doesn't inherently wreck handling the way designing the entire sheetmetal of the car to be vertically taller often does. That said, my (slightly) lifted wagon, while having more volume that most CUVs, does take more work to actually pack cause the ceiling-floor height is much lower. It can fit as much/more stuff than a CUV but since the space is longer and lower you have to be a bit better at car tetris.