I provided a full list of materials that I’ll be using to build the Darkstar Extreme, but just to offer a little preview on what the completed rocket will look like, here are some of the specs. And the picture below is just an example of the finished version – to be clear, I don’t usually post pictures that aren’t my own, but my rocket will look similar to this once it’s done (just probably a different paint job).
note: not my rocket
Length: 101 in. (about 8.5 ft)
Dry weight: 223 oz (about 14 lbs)
Airframe diameter: 4 in.
Motor mount diameter: 75mm
Altimeter/ flight computer: TeleMetrum
Backup altimeter: TBD
Main parachute: 8 ft diameter Rocketman parachute
Drogue parachute: 2 ft diameter Rocketman parachute
Motor: TBD
I’ve already started construction, so I’ll have a lot more updates coming soon.
As promised, below is the full bill of materials that I’m using to build the Darkstar Extreme. It’s important to note that, aside from this particular kit, many of the other things in this list are optional, depending on your particular rocket design; frequently, parts or materials can be swapped out and replaced with other similar items.
not pictured: almost everything
Rocket airframe
Darkstar Extreme kit from Wildman Rocketry, including:
Fiberglass booster (52″ length, 4″ diameter)
Fiberglass payload (24″ length, 4″ diameter)
Fiberglass coupler (11″ length, 4″ diameter)
Fiberglass coupler (6″ length, 4″ diameter)
Fiberglass nose cone (4″ diameter) with aluminum tip
Fiberglass motor mount (75mm diameter)
Fiberglass vent band (1.5″ length, 4″ diameter)
Fiberglass centering rings (x4)
Plywood centering rings (x2)
Fiberglass fins (3/16″ thick)
Aluminum bulk plates (stepped, CNC cut) for e-bay and nose cone
With the workshop newly completed, and a seemingly endless quarantine/ lockdown in effect, it’s time to turn my attention to building a new rocket.
ready to assemble
So far, I’ve built and flown a couple of low and mid power rockets, and I built one high power rocket – the HyperLOC 835, which is a 4″ diameter rocket made primarily from thick cardboard and plywood, with a 54mm motor mount. It can fly on an H, I, or J motor, and I plan to use it once launch events start up again for my L1 certification and probably for my L2 cert as well. It also gave me the opportunity to build my first electronics bay and learn more about flight computers and telemetry.
My next project is a bigger high power rocket: the Darkstar Extreme. This one also has a 4″ diameter but it’s made entirely from fiberglass (except for the aluminum-tipped nosecone and aluminum bulk plates). Fiberglass is significantly stronger than cardboard, wood, or other similar materials; it’s the strongest building material for rockets aside from aluminum.
The other chief advantage of this rocket is a larger 75mm motor mount. More powerful motors come in larger diameters, and this rocket can technically fly on a K, L, or even M motor. An M motor would require me to get my L3 certification, a daunting goal, though one that I plan to achieve in the not too distant future. But I could fly it on a K or L motor as soon as I get my L2 cert.
After unboxing this kit and soaking the airframe pieces in water for 24 hours, I’ve laid out the pieces on my workbench and am ready to start construction. The kit only comes with the major pieces: the fiberglass airframe and nosecone, a few aluminum bulkplates, some basic hardware (forged eye bolts, nuts, washers, and quick links), and nylon recovery harnesses.
The kit does not include the motor (of course), any parachutes, fire blankets, a motor retainer, or certain other necessary hardware (nylon screws/ shear pins, steel screws/ rivets, additional metal bulk plates, etc), so I bought those separately. I also splurged on some kevlar recovery harnesses rather than using the nylon ones that came with the kit because kevlar can withstand significantly higher temperatures and won’t burn easily.
I’ll post a more comprehensive bill of materials separately in case anyone is interested.
Since we had already done all the work involved in running copper wire and conduit outside to bring electricity to the shed, we figured we might as well run some cat 5 (ethernet) cable out there, too, for a wired ethernet connection. I mean, we’d already dug the trench – so why not? An excellent yet rhetorical question.
And as long as we’re running one cat 5 cable, might as well run two. Right?
double the conduit
In view of the larger project of transforming the shed into a workshop, I have to concede that this step was really more along the lines of “what the hell” than anything else. I can’t say it was absolutely necessary. In fact, one might argue it was totally unnecessary. I can’t say that I have any immediate plans to use a wired internet connection out there. The wifi signal from the house certainly reaches the shed, if I needed it. I cannot imagine why I would need a wired connection.
And yet… we already dug the trench, which is the type of work that I’d never want to do again. It may be totally unforeseeable now, but in the unlikely event I suddenly need a wired internet connection in the workshop, it seems worthwhile to invest in just a small amount of extra time and effort now, instead of undertaking another huge (and avoidable) project later.
And to be honest, compared to running electricity out there, this was much easier.
labeling the jacks for future reference
The PVC conduit (3/4″ this time, easily able to hold two ethernet cables) was laid in the trench about 8 inches above the other 1″ conduit with the electrical wires, still about 10 inches below ground level. Next to the house, the conduit runs up vertically along the wall and then over a door and off to the side, right next to the 1″ conduit. I’ll paint them both blue to match the house, eventually, as well. At that end of the conduit, we ran the ethernet cable through the floor and wall of the house, and installed a 4-jack outlet inside, next to the modem/router.
On the other end of the trench, the conduit came up inside the shed to a single junction box, pictured here. It was basically the same process as the electrical wiring, just much simpler inside the shed with a single piece of conduit and single box.
I labeled the jacks and ethernet cable on both ends for future reference and then slapped a metal box cover and 2-jack wall plate on top. Tested both jacks and they are perfectly functional. Success! I may not know why I did this, but I know that the objective was achieved.
ready to use
This means the wiring is complete and I’ve entered a new phase of this project: beautification. Basically, time to clean things up. Outside, there’s an enormous mountain of dirt and rocks that needs to go back into a deep trench and cover up the conduit. I also need to buy a few (hundred) bags of mulch to cover the bare soil, and make the building’s external appearance look at least marginally more presentable (not dissimilar to goals related to my own appearance).
Inside the shop, there’s some general cleanup to do and a few pieces to put back in place. I also need to spend a little time planning the design for the layout, and where tools and equipment should go. It may only be a small 10×10 ft space, but all the more reason that the layout matters: space is at a premium.
I’ll have a few more pictures and a final update once it’s complete. It’ll be ready for building rockets just in time for spring – a.k.a. rocket-building season.
Winter is not a popular time for high power rocket launches. Few clubs actually hold major launch events in the winter months – and the rare brave souls who do are nevertheless subject to the weather. I did find a local club (about a 4 hour drive from Seattle) that has a standing FAA waiver to launch one day each month, but the weather hasn’t been cooperating and so it was cancelled in December, January, February, and March.
Fortunately, spring is here, and clubs start holding many more launches in the coming months, as the weather steadily improves. Unfortunately… COVID-19 hit, and everything is cancelled until further notice. So April is out, and probably May as well. Everyone is at home, with shelter in place and lockdown orders in effect.
On the bright side, it’s a great time to start construction on my next rocket. My most recent project, the HyperLOC 835, has a 4″ diameter body, with a 54mm motor mount. The body is made from (very durable) cardboard and the nosecone is plastic. It’s a great rocket and I’m looking forward to launching it on several different motors, and with a flight computer and electronics bay capable of dual deployment.
My next rocket, though, will be the Wildman Rocketry “Darkstar Extreme.” It also has a 4″ rocket body, but with a 75mm motor mount that can fit more powerful motors, potentially up to an M. (As an aside, an N or O motor only comes in the 98mm variety and would require an even larger diameter motor mount.) The rocket body is made from fiberglass, and the nosecone is fiberglass as well with an aluminum tip.
the darkstar extreme, in sexy and exciting two-dimensional glory
Above is the design file for the Darkstar Extreme, from Rocksim, a rocket design and simulation program.
And here’s the description from the manufacturer, Wildman Rocketry:
“TAKING IT TO THE MAX Leave it to Wildman to push the Darkstar to the Max with this radical upgrade. No Mildmen allowed! This beast is ready to rock on any motor you can stuff in it!”
Can’t go wrong with that. Time to take full advantage of the quarantine.
This post is largely meaningless because I’m not actually including any electronics into this rocket, at least for its first flight. I should probably have titled it “How to build an electronics bay without any electronics.”
Meh.
Starting point for building e-bay: the sled
So first, what the hell is an e-bay?
An electronics bay (or “e-bay” for short) is where you attach any electronics that you want to fly in your rocket. It’s also sometimes called an avionics bay.
What kinds of electronics would you want to fly? Well, there are a lot, and it can get pretty interesting. A few examples of things are:
Altimeter. Measures the maximum height of the rocket (i.e. its apogee).
Explosive charge. If you put black powder on the outside of the e-bay and wire it up with some electronics on the inside, you can manually detonate the charge and cause the rocket body to separate on descent, for another parachute. This is called dual deployment, as you’re deploying two parachutes.
Camera. A GoPro camera can be installed on the outside of the rocket body, wired to electronics stored inside the e-bay.
E-bay mostly assembled: sled and coupler tube
The e-bay is actually pretty easy to assemble. It’s just a few pieces of wood, and some metal screws, washers, and nuts. You start by gluing together the wooden “sled,” and then sliding two very long metal screws through the slots, along one side. Each end has a circular piece of wood with an eyebolt (which can hook to other things like shock cords and parachutes) and it all stays together with some washers and nuts.
E-bay complete! Minus any electronics.
Now, if I actually had any electronics in this thing, it’d be more interesting. But I built it anyway for two very important reasons:
It’s necessary to act as a coupler and keep the rocket body together so it can fly in one piece. Without this, there’s nothing to connect the top and bottom halves of the rocket.
I plan to add electronics to this rocket for future flights.
I finally got my head out of my ass and started putting together this high power rocket. (My head is often firmly lodged in my ass, so extracting it is time-consuming and unusual.)
The basic parts are similar to those in smaller rockets. You build a motor mount (to hold the motor in place) by attaching three centering rings. These rings keep the motor mount tube centered – hence the name – within the larger body tube of the rocket. Then you attach the fins to the motor mount. All of these attachments should be made using a strong wood glue or epoxy.
Motor mount
Later in the process, the larger body tube will slide over the mount and will be flush against the edges of the fins, where they can be secured with glue again on the outside of the rocket. They’re held firmly in place, inside and out, which is important because of the high stresses that will be placed on them during launch.
Motor mount with fins attached
Finally – you attach a steel eyebolt through one of the centering rings, using some washers and nuts and then a strong epoxy to hold it all in place. The purpose of this is so that you can attach it to a strong (and fireproof) cord inside the rocket body, where the other end of the cord is attached to the nose cone, along with a parachute inside for recovery. This allows the rocket’s nose cone to pop off just after the rocket hits apogee (its highest point in the air) and lets the parachute deploy, while ensuring that all the parts stay together on the way down.
The core of the rocket
As a side note, if you include an electronics bay (“e-bay”) in the rocket, which is optional, then you need two cords: one to attach the motor mount to the e-bay, and another to attach the other side of the e-bay to the nose cone, so again everything stays together. The e-bay also have steel eyebolts on both ends for attachment. Just FYI, I’m building and including an empty e-bay in this rocket; I’m not actually installing any electronics in it for the first launch. I want to keep things relatively simple for my level 1 certification flight and will start putting in some interesting electronics for the next launch after that.
If you’ve built and launched any rockets before, you’re probably rolling your eyes at how I’m oversimplifying much of this, and you also likely already identified several inaccurate statements I’ve made. On the other hand, if you’ve never done any of this before, I probably just confused you with a bunch of inadequate and lackluster descriptions.
In fact, I’m pretty sure I’ve failed to satisfy anyone at all with this post. But then, who cares?
Improbable Ventures 