On Sept 19, I went to fly with the Alamo Rocketeers over in China Grove.
Since my truck is broken, I went on my Harley Sportster with whatever I could carry in a knapsack. It's been a long time since I did that. You're limited to rockets that are either small enough, or that disassemble. Sturdy is important too. The Campitch 1 is certainly small enough once the flybar is removed. The hard part is getting by while leaving a new 25LB field box at home. It helps to have friends.
The CP1 sitting on a borrowed pad, loaded with a D12-0
After ignition it's only spun 180 degrees and the wing is already extended for ascent at least part way. The pads' rod angle adjuster is slipping.
That's the wing in the foreground after bouncing off the ground, and tossing up a small cloud of orange soil.
The hub is falling after making a respectable altitude, wingless.
No major damage to speak of, but the cam follower pin was sheared off where it came out of the reinforcement plate on top of the wing. The pin was essentially a 2-56 steel bolt. I've already done repairs and replaced the 2-56 with a 4-40 socket head bolt, and widened the
camtrack slot to take it.
In retrospect it's not too surprising that something happened, given the number of MC's that come apart under centrifigal loads. I would've been much less surprised if the 2-56 pin was simply bent but still there. While I was at it, I installed the heavier return spring I had pre-selected as a possible upgrade. I never liked the limited wing attachment method on this model. A secondary safety attachment would be nice, but how to do it without making the next failure worse?
This is the Campitch 1. The 1st of 2 recently finished
monocopters. Both monos employ quite different wing
control mechanisms, but I decided to build both at once
because most of the construction is routine enough to be
a bit boring and I always mix too much epoxy anyway.
The Campitch 1 uses a system similar to that of the
Rotary Space Ship that I posted about back in March of
this year. When the vehicle begins to rotate, centrifigal
force causes the wing to slide outward on its' pivot rod,
as it does so, a pin on top of the wing root follows a
cam track causing the wing to rotate from down pitch to
up so that it can ascend. Once the motor burns out, the
mono will slow it's spin until a spring can retract the
wing, returning it to down pitch so that it can autorotate
for a gentle landing. No stopping, no falling.
Now, I've done away with the burn string that the
Mousetrap requires. After I work the bugs out on D12's,
I'll be able to fly it on my own small moonburn sugar motors.
I can't remember the last time I was hot to go to a museum.
The Cosmodrome when I was in Kansas for LDRS 12?
That was a space related museum, no surprise there.
This time it was the McNay art museum here in San Antonio.
I've driven past it a 1/2 a million times without knowing it
was even there, this time we were pulling in. What snagged
me was a traveling exhibit of the art of Edward Gorey.
We aint in Kansas anymore, for sure.
We managed to get down there on the final day of the exhibit
and it was great. There were plenty of prints of course, a
mere drop in the bucket from a prolific artist, but mixed in
were occasional originals, and pencil layout sketches. One of
the prettiest displays was a cabinet with hand drawn and
watercolered envelopes that Edward sent to his mother over
the years. I'll spare you further descriptions, the book covers
above are adequate examples. The Doubtful Guest above was
my intro to Ed Gorey, it was read to me/us when quite young,
but then I grew up with hippy school teachers.
My brother and his Sylvia were the ones who went with me,
in fact drove me as I had no transportation at the time. Last
weekend was my birthday and they gave me Ed Gorey's
Amphogorey Again, a compilation. Love it.
The website below is a .net, but it's actually a .com.
http://goreydetails.net/
Other than that go to Amazon for books or simply Google,
there's plenty of E.G. out there.
I've been flying monocopters since 1988. I've also seen
other people fly them. They all shared two common
problems, the first is getting them to stay in one piece
throughout the flight despite the high rotational loads.
I've seen a few fly apart, including some of my own.
Anyone who hangs in there a while, can conquer this
sooner or later.
The second problem is the subject of this post. When
a monocopter's motor shuts off, they typically stop
spinning and fall down. Some falling monocopters will
reaquire spin, either backward or upside down, hopefully
before impact,and make a safe landing.
In short, after getting monocopters to go up reliably, the
next trick is to get them to come back back down safely.
I've seen other recovery methods tried with varied success,
but the coolest will always be autorotation, ie; true
mapleseed recovery. Spinning up, and spinning back down,
without stopping, without falling.
Last fall, I built the 1st step on this quest. I call, it the Flying
Mousetrap. It somewhat looks the part. Mousetrap has a
wing that pivots around the center of lift. There's a spring that
pulls the wing to descent angle, and a length of string to hold
the wing at ascent angle until the motor [D12-3] ejection burns
it through. This gives a timely transition after slowing to
autorotaion speed, but without falling or reversal. The string is
actually dental floss, it's easy to work with at the field, and it
comes in a neat dispenser WITH a built-in cutter.
Minty fresh too.
I don't consider this to be the best approach to the problem.
It's a simple up/down system instead of being reactive, and it
limits the choice of usable motors to ones with suitable delay
and an ejection charge. Since I make my own sugar motors,
I would prefer a system that can use them, and they're all
capped. However, I figured this would be a good first step
that others might prefer.
The 1st flight video was posted by friend John Lee at the time.
http://www.flickr.com/photos/23694991@N03/2953720670/
"A
aarh, Ye be welcome to the Pirate Art Institute"
How many ways can you COPY this pirate?
When wewere kids we would see this art school ad in the back of magazines. "Can you draw this pirate?" or some other bit of cutesy art. "Then enroll today and have a future as
a commercial artist, bla-bla-bla..."
When my brother and I had a print shop back in the late '80's, it became a running joke early on. Customers would bring us totally crappedout art, or ask for art that we didn't
have, or to infringe on copyrights in a questionable manner.
The Pirate Art Institute to the rescue!
We would clip, photocopy, photograph, trace, or redraw, then shoot a transparency, use it to expose a screen, and finally silkscreen print it in [hopefully] vast quantities.
Whatever it took to make a buck.
Anything but FAX!
We refused to install fax service because at least one customer a week would want to fax their art to us. No, nope, nu-uh, don't do it! Most fax looks terrible on a good day. Imagine what it would do to the aforementioned already crapped out art.
When I first saw a pic of what I take to be Quest
Aerospace's dealer table at NARAM 51 I had a primal
moment. I curled my lips back and hooted a few
times while slapping my head. A quick check of the
Quest web site confirmed that what I spotted in the
pic was one of Quest's new kits, the Striker AGM.
Well there's new and then there's new. I've seen that
design before and it takes an old rocketeer to know
where.
Way back when, some of the movers and shakers of
model rocketry got together to create a truly cutting
edge company called Enertek. To make a long and
mostly unknown story short, Enertek failed to make it
into production. Gary Rosenfield and/or his company
Aerotech was a major participant, others participants
went on to form Quest. A lot of Enertek tooling had
already been done and this formed the core of
Aerotech's kit line. The Mantis launch pad, the Initiater,
Strong Arm, and Arcas kits. All underwent some changes
minor or major, but there they were. Enertek was
where C-slot motors and Copperhead igniters [called
Top Shot Igniters then] gestated as well.
A close look at the Astra 2000 will cause a lot of fellow
rocketeers to have a primal reaction themselves, the
critter is obviously based on major components from
a Black Brant II. Nose cone, boattail, and the narrow
waist ring [the white section below the upper fins].
Quest naturally used what was at hand and used a Nike
Smoke nosecone.
I always wanted to build a clone-rok of the Astra 2000,
but being a difficult person, I wanted to stage it and
that upper fin set is dreadfully small. I have cloned a
couple other Enertek vapor-roks over the years, but
that's a story for another day.
Enter the Kaman K-Max.
This is a pure work helicopter employed to transport and set
bulky and heavy objects. It's got a centerline winch and the
fuselage is extra narrow so that the pilot can stick his head out
the sides to look down. The K-Max has a long tailboom so it
doesn't need as much fin area as the Huskie has, but like the
Huskie it doesn't need a tailrotor either. As a direct
consequence, a lot more horsepower is available for lifting.
In fact, 6000lb at sea level, impressive for a 5100lb helicopter.
Another neat design feature shared by all Kaman helicopters,
eggbeater and conventional alike, is the blade control flap.
On other helicopters, the blade pitch is controlled by pitching
it directly at the hub. This requires hydraulic controls on any
helicopter of size. With the blade control flap, the flap is
actuated in the opposite direction and this causes the blade to
twist in the desired direction, Just like the elevator on a
conventional airplane. This means the control input required is
much lighter, [no horsepower robbing hydraulic pump needed]
and because the blade is being controlled out where lift is
created instead of at the hub, the blade trim is more precise
and reactive to the airflow around it on a per blade basis.
This spells greater efficiency and reduced vibration. The
simplified rotor hub also reduces mechanical friction losses,
and reduced aerodynamic drag in forward flight.
Kaman has utilized the K-Max's light and easy main rotor
control and the lack of a squirrely tail rotor to produce a
dual function version that can be remotely controlled as well
as piloted. As far as I know, this is the first full size
helicopter to be flown unmanned. The fact that it can still
be flown manned as well makes it quite versatile.
Kaman has partnered with Lockheed Martin, called Team
K-Max to modify and demonstrate the UAV K-Max for military
operational testing. These modifications are at least the minimum
needed to turn a civilian bush aircraft into one that's integrated
with the 21st century US Navy and Marines.
As kids we lived on and around Randolph AFB, Texas back in
the '60's, Randolph had a squadron [well at least 2 anyway] of
Search and Rescue [SAR] helicopters stationed there. A bravo
idea. At a training base accidents do happen. Back then, the
helicopters they used were the HH43 Kaman Huskie. Along
with patrolling the local flight paths and training areas off
base, they would take part in practice crash rescues and fire
suppression. There were a couple wrecked airframes on the
east side of the base and once a week or so they'd light one
on fire, then scramble a Huskie and the base firetrucks to
come in and put the fire out. Top entertainment for a kid,
a bit nerve wracking for pilot's wives.
As helicopters go, I ALWAYS thought the Kaman Huskie was
the coolest. A stubby little glass box with a whole bunch of tail
fins and those eggbeater twin rotors counter-rotating overhead.
A unique look and a unique sound. At least till recently.
I onced swapped a few beers with a heli pilot who flew USAF
SAR Huskies in Thailand during the "Police Action". He loved the
Huskie, but he said they had one major drawback at the time.
The rotor blades were made of Spruce wood. After a rain or
even a heavy dewfall, the wet blades would sag far enough to
risk a strike during startup. The blades had to be dry before
takeoff. No doubt modern composite blades have little or no
trouble with this.
Wahoo!
ZZakk's Lab passed the 1000 visitor mark today.
Not bad for a blog that's only 5 months old, with 34 posts.
I swear, I accounted for no more than 200 of them myself.
250 tops. By May the count had crept up to 138 for the
month. June practically exploded with 345 visitors. July
may edge that out by a few. According to the average visit
duration, most visitors are even staying long enough to read
something.
Thank you everybody.
