The Darkstar

Over the past few weeks, Ive worked on my darkstar kit and have completed it. I'm not a huge fan of the green but, whatever.

Here's the stats

Diameter: 2.1in
Body Tube: G12 Fiberglass
Fins: 3/32in Fiberglass
Weight: About 5lbs
MMT: 38mm
Nose Cone: Spiral would fiberglass with graphite tip.

The kit includes an AV bay so electronics can be added

Rocket Lingo (what them words mean) Part 1

I use rocket words as part of my every-day language. You will routinely hear me talking about "lawn-darts, Launch lugs, centering rings, cato's, BARs, etc". These words are so common for me that some-times I forget that some people dont speak rocket so here goes:

CATO: When a rocket fails catastrophically, usually by the motor over pressurizing and exploding, destroying the rocket.

Lawn Dart: when the Parachute fails to deploy and the rocket goes"ballistic", hitting the ground at hundreds of miles an hour. This usually means destruction of the rocket.  Lawn Darts are very dangerous, sometimes hitting or coming close to the flight line.

Launch Lug: A small tube glued to the side of the rocket. The launch Rod slips through this tube

a BAR: Born-Again-Rocketeer: a person who was into the hobby as a child and came back to it as an adult.

Centering Rings: Doughnut shaped rings that center a smaller tube in a larger tube

Rail buttons: Small "buttons" that are screwed into the side of the rocket. These buttons slide down a launch rail. They are a great alternative to launch lugs:

Shock Cord: The cord that ties the Upper section to the lower section, It is usually made of Nylon, Kevlar or elastic.

Motor Retainer: A device that secures the motor to the back of the rocket.

Apogee: The peak of the flight, when you want the parachute to eject.

Shred: When the rocket exceeds the speed in which it can hold together. The air moving around the rocket tears it apart. Shreds are common in large minimum diameter rocket.

3FNC: 3 fins and a Nose Cone. Nothing special about the rocket.  Most of my rockets are 3FNCs

Airframe: The tube on the rocket.

APCP: The common propellant for rocket engines F+. Similar to the propellant Nasa uses.

Zipper: When the Shock Cord tears through the airframe. This happens when the parachute ejects to early or to late

Igniter: An Electrically fired peice of pyrogen that lights the motor.

Fillet: Adhesive that is layed against the corner of joining parts and smoothed. Alex is terrible at making these.

Minimum diameter Rocket: A rocket where the motor tube is the airframe tube. These rockets are meant for speed.

LPR: Low Powered Rocket: A-D motors

MPR: Mid Power Rocket: E-G motors

HPR: High Power Rocket: H-O (and above) Motors

Dual Deployment: One (small) parachute is fired at Apogee. The small parachute brings the rocket down quickly. At a certain altitude (300-1000ft usually) A larger parachute is opened. The larger chute brings the rocket down slowly. 

End Of Part 1

Useful websites

A lot of learning goes on online in rocketry, whether you're just starting building rockets or if you have been in the hobby for a while. Here are my personal favorite rocketry websites. If you just want to research a kit you are thinking of buying, if you dont know how something works or if you just need some build tips.
Here ya go...

EMRR (RocketReviews.com)
Emrr is a website with lots of tool, tips and reviews. With more then 4000 reviews of different rocketry products. Whenever I am deciding what kit to buy, EMRR is the first place I look. Most reviews contain details on how to build the kit, the Pros and Cons, The parts list and if the reviewer thought it would be a good buy. Along with thousand of reviews, They also have a "hints and tips" section, motor information and more. I could spend hours on the EMRR Website.

Thrust Curve
Thrust Curve is an site that has more motor information then a rocketeer could want. Motor info contains thrust curves, total NS, Average NS, Propellant type, Propellant Weight, etc. Along with motor info they have a quick and dirty simulator.

The Rocketry Forum
The rocketry forum is a great place for asking questions, even stupid ones.You'll get all the information you need and more! Eveyone is very friendly and helpfull. Along with asking questions you can explore the galleries or buy or sell something on the yard sale. Having an account is a must.

Info Central
A great place for tips on just about everything.

Apogee Components
Apogee is both a vendor and a place to learn something. They have an extensive collection of newsletter articles that are well worth the read. Along with the newsletter articles, they have a good collection of how to videos.

Rocketry Planet
 Rocketry Planet has tons of articles, builds, news stories, etc.

If you have any more you want me to include, please leave a comment below and I'll include it.

package

this was waiting for me when I got home.

for those of you who dont know what this is. This is a Wildman Darkstar kit. It's all fiberglass and usually retails for $125. I got it for $79 at the black friday sale.

Thanks for Santa and The grand parents for funding this.....

Rocketry Materials

I'll be comparing different materials to use for rocket body tubes (airframes). Most rocketeers will favor one more than another. When switching from LPR rockets to MPR and HPR rockets, knowledge of airframe materials is essential.

I'll be comparing 1 foot of 4in tubing as far as price goes.

Cardboard:
Cardboard is the most widely used airframe material in MPR and HPR rocketry. Cardboard Airframes are very similar to airframes used low power rockets, just thicker. The most common Manufacturer of cardboard tubes is LOC Precision and most online vendors stock cardboard tubes, usually from LOC. Cardboard tubes are the cheapest tubes available but has the tendency to "crimp" or "crumple" after a hard landing. Not much will be left after a lawn dart.
Cardboard tubes are also difficult to finish, having deep spirals that need to be filled.
Price: $3.69 
Availability: 9/10
Heat Resistance: 5/10
Durability: 3/10
Finishing: 4/10
Weight: 3/10

Picture from Apogee Componets

Phenolic:
Phenolic is similar to cardboard and the two are often confused. Phenolic is more brittle and tends to "shatter" instead of "crumple". It is more stiff then cardboard tubes and harder to cut. It took me twice the time to slot as compared a cardboard tubes. The most common manufacturer of phenolic tubes is Public Missiles Limited (PML). Phenolic tubes are even harder to finish then cardboard tubes, having even deeper spirals. Phenolic is my choice for motor mounts because of it's heat resistance and because it doesnt buckle like cardboard.
Price: $6.17
Availability: 6/10
Heat Resistance: 6/10
Durability: 3/10
Finishing:3/10
Weight: 5/10

Fiberglass
Fiberglass is becoming more and more popular as an airframe material. Strength is very good. Most fiberglass tubes will survive lawn-darts, premature ejections and almost everything that phenolic tubes or cardboard tubes cant handle. The major minus is the price, Fiberglass is one of the most expensive materials to use. Fiberglass is very easy to finish because it has no spirals to fill. Fiberglass is also very heavy. Several manufactures make fiberglass tubes like Madcow Rocketry and Performance rocketry, sold at Rocketry warehouse.
Price: $22
Availability: 4/10
Heat Resistance: 8/10
Durability: 8/10
Finishing: 7/10
Weight: 8/10

Blue Tube 2.0:
Blue Tube is a good mix of pluses and minuses of each airframe. Blue tube is much more durable then cardboard and much cheaper then fiberglass. Blue tube rockets are durable and are very forgiving on rough landings, light blue tube rockets easily survive lawn darts and other recovery system failures. Blue tube is made of a fish-paper like material used by the military. The only drawback is, blue tube is heavy ans has spirals that need filling.
Price: $10
Avalibility: 4/10
Heat Resistance: 6/10
Durability: 7/10
Finishing:3/10
Weight: 6.5/10

Blue Tube

Quantum (QT): 
Quantum tube in a category all by itself, it is not a composite like Fiberglass and Carbon fiber but not a paper like cardboard, phenolic, or blue tube. Quantum tubing is a plastic tubing meant for high durability and easy finishing. It has a smooth texture and is very easy to achieve a good finish. The only manufacturer that produces QT is Public Missiles Limited PML. QT is not a good airframe for high heat applications, such as minimum diameter rockets. Quantum Tube expands and contracts with temperature.
Price:$7.50
Availability: 3/10
Heat Resistance: 2/10
Durability: 6/10
Finishing: 7/10
Weight: 5/10

Carbon Fiber:
Carbon fiber is the highest quality airframe material money can buy, although it takes quite a bit of money. Carbon fiber is the most expensive airframe, costing more then double the amount of fiberglass (around $200 for a 4x48" airframe). Carbon fiber is practically unbreakable. It is used mostly on large minimum diameter rockets breaking mach 2 or more although some small rockets are built out of CF because that's awesome.
Price: $48
Availability: 3/10
Heat Resistance: 10/10
Durability: 10
Finishing: 7/10
Weight: 7/10

An all CF rocket

Fiberglassed Phenolic:
'Glassed phenolic is a great mix between Phenolic and Fiberglass. It's strong, light and cheaper then fiberglass. Several Manufactures sell glassed airframes. Some of them are: Public Missiles, What's Up Hobbies, and Giant Leap Rocketry. Many times the builders will fiberglass the tubes themselves, this is a cost saving alternative to buying the tubes pre-glassed. Fiberglass cloth is wetted-out with epoxy and wrapped around the tube. Doing it yourself is much cheaper the buying a pre glassed one:
Price: $17.50 / $8 (self wrapped)
Availability: 3/10
Hear Resistance: 6/10
Durability: 7/10
Finishing: 3/10
Weight: 5/10  

VernK's fiberglassing set up.

 

New rocket:

me with the rocket

the butt

the rocket

details later coming soon!

Aerotech vs. CTI

                                  Aerotech vs. Cesaroni (up to 54mm motors)

   For those of you who dont know what both of these words means: Aerotech (AT) and Cesaroni (CTI) are the largest manufacturers of mid-power and high-power motors. Both make AP based rocket motors from E to N ( CTI now has a few "O" motors in production). While they both make basically the same product, they both have many differences. One of the big questions people ask when they think about getting a certification is: What company should I go with? It would be best to go with whatever your local motor vendor carries. In my case, Bruce (our motor vendor) carries both Aerotech and CTI reloads. If you motor vendor carries both you have to make a decision based on what best fits your needs so, here is a comparison: 

Cases:

Both At and CTI require you to purchase a case to fly reloads. A case is an aluminum tube that the actual reload fits into. Without the case the propellant would just burn out the sides and your rocket wouldnt get off the ground. AT and CTI both have different case systems, AT reloads will not work in CTI cases, and CTI reloads do not work in AT cases.
         A CTI 38 case has a plug at one side and internal threads at the other. The motor is slid into the case and an aft closure is screwn into it. 38mm motors have the Aft closure moulded into the motor, which makes buying cases a bit cheaper.
         Aerotech cases consist of : a case, a forward closure and an aft closure (and sometimes a thrust ring). The case has internal threads on both sides and the closures screw into both ends. The forward closure has a well for the BP to be stored in (unless the motor is plugged). The aft closure has a raised edge that bumps up against the motor tube. 
       CTI cases are much cheaper then an AT case. A 38mm 2G case (H motors) will cost about $30 while an Aerotech 38/240 (H motors) will cost about $90. However, once you buy a set of closures, you can use them in any aerotech 38mm case. This makes buying cases easier.
       Cesaroni and Aerotech both now have a reload adapter system. Cesaroni uses spaces so that it is possible to fly a 2 grain motor in a 4 grain case. This gives you lots more options in one case. for example, with a 3 grain (3G) and 2 spacers you can use over 20 different reloads, as opposed to the eight you would be able to use without the spacers. Aerotech recently released it's own spacer system with a floating forward closure. Still, the system is more expensive then CTI's spacers.

An Aerotech 36/360 case (with closures)
Photo from Apogee Components

 Motor Assembly

         Motor assembly also differs between companies. A CTI reload is about 75% pre-assembled. The grains come in a central liner with the delay and nozzle pre-installed. CTI's delay's are adjustable. To adjust the delay, use the delay drilling tool. The delay half is inserted into the tool and a drill bit drills out the proper amount of delay. You slip the delay back into the liner, then slip the liner back into the case and tighten it. That's it! At motors take quite a bit more time to build. The first time I built an AT reload, it took me 45min. Now it takes me about 10, depending on the motor. AT reloads come with independent propellant grains, which slide into a liner. You need to grease o-rings, install the nozzle and do other things until the motor is assembled. If you might enjoy assembling motors, aerotech might be the way to go. If you just want a quick reload to build you might want to consider CTI.

Reloads

        When deciding which manufacturer to chose a big thing to take into account is the cost of the motors. Aerotech's motors are tons cheaper per-flight then cesaroni motors. For example, if I wanted to fly a small I motor, an I161W would cost me about $38 but a Cesaroni I345 would cost me about $43. Luckily, our local motor vendor carries an I161 for $25! 

Propellants:

CTI and AT both have different kinds of propellants to choose from. Most are white, red, green, black "sparky" or fast burning. CTI and AT's propellants differ slightly AT's reds are different then CTI's red and CTI's fastburning is different then AT's fastburning. Most people have opinions on which propellant they like more. Here's mine: 

The following is just my opinion: 

(CTI)White Thunder vs. (AT)White Lightning: I like White Lighting quite a bit more. White Lighting has a longer burn time and more smoke. White Thunder has a quick burn time and not much smoke. Both Propellants are widely available.  

White thunder (an I345)

White Lighting (an I161)

Blue Thunder (AT) vs. Blue streak (CTI): Both are blue Propellants. The blue thunder has very little smoke and very little flame but buns very fast. CTI's Blue Streak has different characteristics. Blue Streaks have much more flame then a Blue Thunder. Just look at the pictures below:  

An Aerotech F52-8 Blue Thunder

A CTI F36 Blue streak

Redline (AT) vs Red Lighting (CTI): I love a good Redline. In my experience, Redlines have more flame then Red Lightings. Some Red Lightings are cool too. I love the G54R with a 3 second burn.

Red Lighting

Redline

Warp-9 vs V-max: Warp 9 and Vmax are both fast-burning propellants. Aerotech's Warp 9 is the fastest burning propellant available, with a G motor burning in .4 seconds. CTI's Propellant is a bit slower, burning in .7 seconds. Both these propellants are used for both mach-breaking fast flights or heavy rockets that need a little extra "oomph". Even though the Warp-9 burns faster, I like the Vmaxs more here is the reason: Warp-9 motors are always plugged so the require the use of an altimeter to fire of the ejection charges. V-Max motors use a conventional delay. Also, Aerotech Warp-9s cost about 1/3 more then regular motor, V-Maxs cost the same. 

A H999 warp-9

A H400 V-max

Mojave Green(AT) vs. Green (CTI) CTI currently has very few green motors. They only have 2 Green motors in the 38mm engines. Mojave green is widely available. 

A CTI green

An Aerotech Mojave Green. 

Black jack (AT) vs. Smokey Sam (CTI). Both of these motors are black motors. Instead of a flame they have thick, black smoke. Aerotech's BlackJack is a slow burning propellant with a long burn time. CTI's Smokey Sam is a quick burning propellant.

An F22J

An H178DM
Photo by Jeff M.

Other Propellants:

Both AT and CTI have propellants that cannot be cross-compared. Here they are:

Metalstorm: Metalstorm is a "sparky propellant" which means that Sparks are thrown of the motor along with the flame, personally "sparkies" are my favorite to watch. Metalstorm combines a White flame, white smoke and a shower of sparks. AT currently has the only "white sparky" Propellant.

My Mach mobile on a G75M 

Skidmark vs Dark Matter: Aerotech and CTI now both have a  black "sparky propellant". Both have black smoke, bright yellow sparks and a loud roar. Ive flown both types and both have their ups and downs. Both motors will be less powerful then the other motors in the same case. You wont use these motors for preformance, just show. In my experience, aerotech's DM has more sparks, more smoke, and more roar then the CTI equivalent, but a lower ISP. Since DM has not been around that long, There are only a handfull of reloads available, while skidmarks are available in almost every case size.

An H178DM 

An I180 Skidmark

Imax: Imax is a strange propellant, It starts off burning green and turns black before burnout. Imax also has a  higher propellant density then other motors, making it common for altitude record attempts.

Photo by Jurvetson

Classic: Classic is a CTI Propellant that burns clearly, with little smoke. Imagine a large Estes engine.

an H90 classic.

USEFUL LINKS:
CTI 
Aerotech
Jurvetson (amazing pictures)

October launch!

a few weeks ago we had our UROC October launch. Simon was unable to make it so I took Kade instead. I flew my "Hobo" on the G80 skid. There were lots of great flights.
All photos were taken by Kade.

 WATCH VIDEO HERE!

BYU Rocket on a K550W

Blue motor

Smokey motor

A G76G

The hybrid rocket.