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After
lobbying by some interested members, DARS scheduled a night
launch. So I built this rocket for night flying, and modified
another as well.
And then it rained, and the launch was scrubbed. And it
happened again, and again. So I finally flew it at an indy launch
one night 
One of the instigators had scrounged some plastic tubes which had been
used as cores for plotter paper rolls. They are a bit
heavy, but one heavy piece doesn't ruin a rocktet's performance.
But several heavy pieces will. And that's what happened with this
rocket. Because it has a 29mm motor mount, it's not a huge
problem. A lot of woosh makes up for a heavy rocket 
The extra heft begins with the airframe. A thick-walled, 38mm, paper motor tube was used.
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Fins are 1/8" birch plywood with balsa fillets. The balsa was triangular shaped molding for use in model airplanes.
In the pic at right, the balsa has had a first pass of rough sanding.
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The launch lugs require offset for the launch rod to clear the payload section.
The aft lug was mounted to a fin. The forward lug was then mounted on a standoff aligned with the aft lug.
The three flashlights are cheapies from the dollar store for use on key
chains. They are intended to give the rocket visibility from
behind to make tracking easier during boost.
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Below is a close-up of one of the flashlights. They are attached to the
hard points with tie wraps.
The on-off switch is momentary contact. A
groove was filed into it to allow another tie wrap to be used to hold
the button down to keep the light on.
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More
added weight comes from the transition. This is turned from
cedar. The forward end is hollowed out to receive the base of the
light mast. A drywall screw secures the mast in in place.
A balsa transition is surely possible, but my experience is that balsa
is too easy to make crooked. It only takes a tiny error in either
shoulder to end up with the nosetip off axis by a 1/4" or more.
So, at the expense of weight, a harder wood is preferred for
transitions. It's easier to keep it true on the lathe (IMHO).
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The mast is a 5/16" hardwood dowel.
It has three tiers of three LEDs each. The three groups are wired
in parallel to the 9V battery at bottom. Power is switched on by
connecting the battery clip.
The three LEDs in each tier are wired in series. One LED (in each
tier) is a blinker with the result that all three LEDs blink
together. Thus, all three tiers blink.
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| The LED leads were bent at 90°, then taped to the mast. Connections were secured with solder.
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a close-up shot of the payload tube. It's translucent plastic,
and has grooves molded into it. Being translucent, it attenuates
the light somewhat, but also diffuses it which tends to make the
payload tube glow. The high brightness LEDs are very focussed, so
they're not nearly so bright not aligned with their sweetspots.
The duffusion tends to counter this making the lighting effect more
omnidirectional.
Another drawback of the plastic is its weight which further adds to the list of heavy components in the Niteloader.
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At the top of the payload
section, a hole exposes the screw which holds the nosecone on the mast
which in turn holds the payload section in place.
The nosecone was turned from cedar. It was thoroughly hollowed
out so it's not very heavy, but does add some weight versus a balsa
cone.
Between the thick-walled airframe, cedar transition and nosecone, and
plastic payload section, the rocket turned out pretty heavy.
On top of the heaviness, the lights aren't really very bright. Frankly, they're pretty lame.
Considering the weight and lack of brightness, the rocket is a turd. I guess that's why they say 'stuff happens'
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That said, it's still a
good looking rocket. At left is a liftoff shot of it during a
daytime checkout flight on an F39. It flies just fine.
Doug
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1-3-2009
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