Photo courtesy of Tim Sapp
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October 21, 2004
After over a year's delay, I finally made my Level 2 attempt on Saturday,
October 16, 2004 at DARS' Shoot for the
Stars launch in Windom, Texas.
This 6" upscale Midget
was my Level 2 vehicle. The airframe was fiberglassed PML phenolic
tubing. The fins were 1/4" lite-ply and potentially the achilles
heel of this rocket. While also 'glassed, sticking out way aft made
them susceptible to breaking at touchdown.
Unlike the original Midget, there was no booster stage. That's
not appropriate for a Level 2 attempt. I'll save that for later :)
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| Left: Here's yours truly striking a pose with the Midget600
loaded on the launch pad ready to go..
RustOleum was used for the yellow and black. |
| The nosecone was glued
up from yellow wood with the aft 2/3 hollow, then turned on a lathe.
It's heavy, but necessary for stability. It was built hollow for
two reasons. One was to allow extra space for the recovery harness
and nose ballast. The other is because it's very difficult boring
such a large hole; it's much easier to just build it in.
The rocket was originally built in a crash program to get my L2 last
year only to have the launch rained out. And many more since then.
It's been over a year, but I finally made it out to fly this thing.
I even had to retake the L2 written test since the previous one expired.
At one point, folks around Texas started calling us (DARS)
the Dallas Area Rain Service because so many of our launches were rained
out.
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| Above: This photo shows the hollowed base of the nosecone and the
u-bolt for recovery attach.
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Photo courtesy of Tim Sapp
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Left: Here's a great shot of the liftoff
on a Cesaroni J285. It was a beautiful flight...for the most part
:(
Because of the rush to build this, some tradeoffs were made. The
lite-ply fins were one of those. They've been 'glassed, but because
they're so big, they're still susceptible to getting broken. And
adding material to strengthen them only puts more weight in the worst place
on the rocket - at the back.
To try to minimize the chances of recovery damage, an external recovery
attachment point was installed on the boattail. The u-bolt and quicklink
are just visible between the fins on the right.
The idea was to bring it down throat first so that it didn't land on
the fins.
The recovery harness runs from the u-bolt, up the side and then into
the airframe through a notch just below the nosecone.
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| Right: Here's a cool shot from below as the Midget600
raced skyward.
The flight was spectacular. A beautiful, straight up boost.
No weathercocking at all. And not too fast, either. A truly
majestic climb. |
Photo courtesy of Tim Sapp
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Photo courtesy of Tim Sapp
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For whatever reason, the nosecone stuck in the airframe.
Several saw the ejection charge fire, but the nosecone didn't budge.
Left: Here's the Midget600 in its death dive. It's a
feeling that's difficult to deal with, but at least I didn't cry.
Lawndart. Ouch. It wasn't a very high tech rocket, but it
proved to be very pleasing to the eye, both on display and in its lone
flight. Needless to say, I'm a little bummed.
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| Right: Here's the noscone stuck in the ground.
The forward airframe was destroyed. Its remains were scattered, but
part of it lines the hole around the nosecone. |
Photo courtesy of Pelham Swift
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Photo courtesy of Pelham Swift
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Left: Michael gave me a ride out to the crash site.
We both tried pulling the nosecone out of the ground. Eventually,
we pulled it out with his truck. |
| Right: The tail section still resembles a rocket.
But it's really ugly. Nothing left to salvage here but the nylon
strap and kevlar cord. |
Photo courtesy of Pelham Swift
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Photo courtesy of Pelham Swift
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| Above: Jordan and her friend Sarah joined me to
recover the rocket. The best advice I got that day was to take a
plastic bag to the crash site. "You'll need it." |
| All the aforementioned weight and strength analysis points out one
of the weaknesses of upscaling from model rockets. HPR rockets tend
to not have fins extending aft of the airframe. This keeps them from
being exposed to hard landings. But when a rocket is upscaled, that's
not an option. However, none of this was ever tested. We don't
know how the fins would have held up to the stresses of a parachute landing.
I've wanted to try some of the high tech material such as the carbon
fiber honeycomb that's available, or to build up fins from hardwood strips
and foam laminated with fiberglass or 1/64" plywood. Looks like I'll
get that chance now. |
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Left: Other than the chute and motor case, there wasn't
much salvageable. With some effort, the nosecone can be repaired,
but right now that's iffy. The fin at right came off in the crash. Here it's been
partially reinserted into the foamed fin can |
10-21-2004
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