Blog Annoyance

The previous blogpost has the wrong date.
It should've read June, not January.
The reason why is smart software that is dumber than I would've thought.
Instead of using the date when it was actually posted, the software used the date from when the post was first created and saved as a draft, this despite extensive editing and additions the day I actually posted it. While the draft date might be useful information to me in a nagging sort of way, it is totally useless to the reader.
There are a couple other drafts scattered in my Edit Posts section, and if I decide to use them eventually, I'll now have to remember to paste them into a new post rather than risk them posting with the wrong date, or worse, being inserted amidst older posts outright. I would consider that to be an example of revisionist history, albeit minor and unintended. Rereading my old posts, I've run across quite a bit of stuff that could use reediting, but most are of the typesetting or spelling variety plus a few phrases that could've been done better. Just not worth the effort. If I found some gross errors, that might be a different story
People can rip pages from books, but that leaves evidence of the fact. People can burn books, but there are always more books. Be wary of the web, because computer editing and manipulation are very hard, or impossible to detect, especially text. Anyone can post to, or reedit a Wiki entry.

Beware of Rotating Parts!

At a typical modroc launch, any monocopter pads get set up nearby other pads in order to share launch control wires. I already posted about the [extremely] close call I had on the Pitchwing-2 first flight. This time it was another new monocopter called the Wig-Wag.

Right after takeoff the Wig-Wag drifted downwind slightly and the wingtip collide with an 1/8" stainless steel launch rod. The rod was mounted in the same launch rack that the Campitch-2 didn't hit. The launch rod was ruint [Texan for ruined, but with more finality], totally FUBAR! The only part of the rod that was still straight was the 1" section clamped in the pad base. One might expect the rod to be bent away from the direction of impact, or bent sharply toward DOI at the point of impact. Nope, neither. After the sharp 20-25deg bend away from DOI at the base the remaining rod length was bent in a continuous arc like a bow. quite strange really. I'm an old hand at straightening bent metal but this was scrap!

I owed Art Applewhite a new launch rod. Luckily I had some spares at home.

The monocopter wing was fiberglassed balsa and suffered only a 1/2" deep notch in the leading edge, and the MC went on to complete a nominal flight. That's right, it kept on flying.

Repairs were relatively easy. I sawed out and replaced a square of balsa, filled the gaps with Cya and micro balloons, then sanded the fill to shape and reinforced the area with a fiberglass patch. Since the wing is already a veteran of many flights on the Pitch Wing 1, I didn't even bother to touchup the paint.

I'm glad this first flight was only on a C6, if it'd been a D12, damage might've been much worse.

Campitch 2, 1st Short Hop

Pics by John Lee

These are pics of the Campitch 2's 1st flight. Just a test hop if you will. I would've posted these pics before if I'd known they existed. They were uploaded out of flight sequence at Flickr, so I didn't find them till the other night.

When I designed the CP-2, I meant it to be an 'E' powered monocopter and I succeeded well. A 'D' motor barely gets it into the air as the photos illustrate. Only about five feet up, woo-hoo!

I hate "reinventing the wheel" [Unless it can become a perverted mockery of science!], and I see no point in rewriting the flight description when I can copy & paste from one of my own previous blogposts.

>>>>>The first flight back in August [2010] had us rolling on the ground, and we weren't even on fire! I launched the CP-2 on an Estes D12-3, it took off from a 2x4 pad low on the ground and ascended to no more than 3ft [more like 5ft] as it travelled 5-6ft upwind, then curved left going just over a modroc launch rack passing through a gap in the launch rods with scant centimeters to spare, then it drifted back downwind to land right next to it's takeoff point. It looked a lot like an olympic highjumper in action.<<<<<

Lucky thing, one of the launch rods was missing that day. [And that leads to another story.]

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

I haven't posted lately because I had to move. With major assistance from my brother, I started moving early Thanksgiving week. It took us nearly 2 weeks, after which there was a lot of settling in and rearrangement of storage, closely followed by more holidays.

While I have my own PC up and running, it currently has no online connection. I have to borrow time on other computers.

Success of the Campitch 2, an update

The Alamo Rocketeers had a night launch and weenie roast on Nov 20. The first time I've done any night flying in years and years. We started early enough to do some day flying too.
Right after sundown I flew the Campitch 2 without any visual augmentation. I used an entirely antique Aerotech E10-4wl moonburner that I had been hanging onto for years. The flight was fantastic, a complete success and a worthy use for that old motor. It was a blustery evening but the CP-2 maintained good stability, achieved a respectable altitude and was in full autorotation mode about 1/2 way down, landing less than 100 feet downwind.

After the last time I flew the CP-2 I obtained a new piece of 3/16" graphite tubing, cutting a new flybar 3" longer and then added internal wire tipweights to increase the weight from 11g to about 20g, nearly doubled.

Snaking the thermalite ignitor fuse into the offset port on that E10 was definitely cause for reminiscence. Ahhh... the moonburners that I have known. I initiated the thermalite with a
Quest Q2 ignitor. If I'd remembered them Id've used a flashbulb initiator to wow the crowd.

Moonburner Motors Get Bent

First time I've tried to upload a vid clip.
Hope it works OK.


When I first started experimenting with making my own sugar motors, I made several decisions under their own merits which eventually lead to an epiphany. When combined, these factors
created an interesting moonburn synergy.

First, I chose to use 15/16" diameter [24mm] phenolic cases that are thicker walled, than Aerotech, being 3/4"id instead of 7/8"id. To simplify the nozzle issue, I elected to buy Aerotech nozzles instead of producing my own from scratch, though this requires that I turn down the nozzle OD to fit my cases. Like most other experimental motor makers, I still wanted to maximize the propellant fraction. I decided to pour directly in the cases, including the convergent frustrum. No casting tubes or liners required. After only a couple false steps, I tried silicone tubing as my core spindles, which works great when casting sugar propellant. The silicone spindles are longer than the motor case, and extend all the way from the nozzle to beyond the top end. A rod or dowel, as the case may be, the same diameter as the nozzle throat, but loose inside the silicone, extends through, acting as an alignment guide and throat plug. After curing, the rod is drawn out, then with a steady tug, the silicone stretches, losing contact with the core wall, and pops right out pretty as you please.

Though I started with core burners, a major goal all along was to make moonburners since I couldn't buy any commercial ones for a long time, and then when I could, only in 'J' and above.
With the old Aerotech D-G moonburners, the fuel was precast and had a drilled port to one side that you would have to blindly hunt for with a piece of 'S' bent Thermalite. Even for
someone experienced with these motors, it was tough to install, tough on the Thermalite and chuffed too often at the best of times.
Epiphany; My flexible silicone spindles need not be straight. I attached the silicone tubing to the nozzle throat with a short plug, then 'S' turned the tubing over to the case wall where
it's held in place with a suitably fashioned wire clip. This creates a smooth pathway for the ignitor during installation AND expulsion, even when using Copperheads. This 'S' turn also creates a short area of coreburn configuration near the nozzle, producing a higher takeoff spike before it settles into full moonburn mode. Perfect for a medium size 'D'-'E' bird.

Another goal of making motors was that my wife [now ex] and I had always been into clustering, especially air-starts. Estes 'D's are great for this but keep costing more and more.
I was already enamored with the idea of focused thrust [long before Flis-Kits] and wanted a way to add that feature to already existing rockets with air-start clusters. The curvy silicone core spindles work even better with the angled nozzles. Now there's only one shallow bend instead of an 'S' curve. This also reduces the coreburn section, making the motor more of a true moonburner. Since classic moons ramp up and down more gently than other motors, they are less prone to affecting the flightpath if multiple ignitions are uneven, or lacking. Focused thrust, of course, further reduces possible flightpath disturbances. I made a 10 degree angled nozzle holder for my lathe, so that I could modify the Aerotech nozzles before gluing them into the cases.












Angled lathe tooling with unmodified nozzle
installed, and a used angle nozzle motor.

Campitch 2

Pics by: KeithAlanK

This is the new improved Campitch 2.
It has the same features as the defunk Campitch 1 but is larger and beefier. Most notable is that the wing is much larger, by nearly 50%. The span is 2" longer, but the wing is made from
1/4" x 4" Sig airfoil stock instead of 3/16" x 3" stock. The thicker wing allows for a thicker 3/16" carbon pivot rod instead of the 1/8" carbon, then steel pivot rod on the CP-1. The hub assembly is about 1/2" longer on the motor side.

The CP-2 is already leading a better, or at least charmed, life than the CP-1 did. It has made three flights so far with nothing worse than some burn through charring [routine] and a ding on the wing tip.

The first flight back in August had us rolling on the ground, and we weren't even on fire! I launched the CP-2 on an Estes D12-3, it took off from a 2x4 pad low on the ground and ascended to no more than 3ft as it travelled 5-6ft upwind, then curved left going just over a modroc launch rack passing through a gap in the launch rods with scant centimeters to spare, then it drifted back downwind to land right next to it's takeoff point. It looked a lot like an olympic highjumper in action.

Todd, one of my flying buddies said he'd buy me lunch if I would fly it again. I didn't have any more suitable motors for it, so I told him I would if he could donate an Estes E9. For various reasons, I had yet to use any E9's before, so this one was my 1st. Well that turned in a perfect flight, 60-70ft up, transitioning to full autorotation mode about 1/2 way down and landing about 100ft downwind.

September launch dates were all rained out, so I had to wait till October for flight #3. Since the CP-2 flew so well on an E9 I figured it could handle one of my long sugar moonburners. These are sized the same as the E9 though heavier start to finish and has a higher sustain burn and longer duration. Well this spinny thang tookoff and immediately tilted about 45 degrees downwind for about 100ft then curved back and up in a boomerang turn till it was knife edged, pointing into the wind, at which point it ran out of sugar and dropped straight into the ground. Amazingly, the only damage was a little mushing of the wingtip, easily fixed by supergluing my fingertips to it.
The only other time I ever saw a monocopter with quite that flight profile was when I actually launched one with no flybar installed at all. Obviously a flybar with more authority is needed.
Not too surprising really, since the flybar was the same one the smaller CP-1 used.

Tig Bitty Alert

The orange paper has an exact [from the screen] print of
the other side of the shot glass.

This blogpost was substantially written by my brother Keith
and first appeared in his blog; Zzakk's Garage last year. I
edited it to make myself 1st person and made some additions.

Back in 1991 when my brother and I owned a screen printing
company (that did everything but T-shirts) we used to make
personal items from time to time. Keith handled the artwork
/typsetting and darkroom, plus made the screens--I was in
charge of the machinery and tooling (makes perfect sense if
you know us) and then we would do the actual printing
together.

I had Keith pirate the art of Patty Melt [one of Cherry's friends]
whipping out her tig old bitties from a Cherry Comics adult
comic book, and we printed at most a dozen shot glasses
[1 sub-carton]. We shipped two of the shot glasses to Larry
Welz, the comic's author, who then sent us the original and
never-seen-before-now drawing that's in the frame. We
traded a few comments about our favorite liquors and
thoughts on doing a production run. Unfortunately, our
epoxy based glass ink wasn't durable enough for hard use
[we termed it "Souvineer Quality"] so we declined due
to warranty concerns.

We put milk in the glass so our printing would be legible in
the photo, then drank it. Till someone else brought it up,
we never thought about the humor of our choice of liquid.

Probably the only time Keith has tasted white milk since
we made the shotglasses 18 years ago.
Personally, I can't get enough of the stuff.

The first issue of Cherry Comics was titled Cherry Poptart.
A great way to infuriate Kelloggs and Archie Comics at the
same time. There were some not so thinly disguised Archie
characters in that first issue too.

Time to Google Larry Welz and see what he's up to lately.
www.cherrycomics.com If you're 18 or older.

Girl Genius Comics, Steampunk Heaven

Not an artistic page but
Agatha's rant says it all.













2008 Hugo award


A quick plug for Girl Genius comics.
The hero is Agatha Heterodyne, an extremely sparky
mad scientist from a long and dangerous family of
sparky mad scientists. A nice girl actually, but she's
learning fast.
I wouldn't mind being her Lab Assistant.
Phil & Kaja Foglio just uploaded this great photo of
the Hugo award they won for Best Graphic Novel
of 2008. Great trophy. Absolutely fantastic comic.
I can't recommend it enough. You can read a new
page every weekday online, but support your artist
and buy the books, I have the 1st 7 or 8 plus a lot
of other Foglio comics and cool products.

I installed a link in the lefthand sidebar some months
ago but I wasn't fired up enough to do a blogpost
about it till now.

Back in the Saddle, NOT!

I had high hopes for upping my post rate this fall
here at the Lab, but such is not going to be the case.

In late September my landline was disconnected and
I about refuse to pay a further autodebited dime to
ATT/yahoo for their klugey [sp?] email that I have to
constantly wait for advertising to load on. I expect
advertising on Yahoo free sites, but not on something
costing me over $17/mo and is slower than ever already.
GRRRRR!
When the email software switched over, the previously
full featured address book lost everything except the
names and email addresses. All the phone numbers, all
the USPS addresses, all the aliases and side notes. ALL
GONE! DOUBLE GA-ERRRRR!!!
Of course this means my access is limited at the moment,
and I'm losing all my old email files and peoples addresses.

So my friends & relations who read this, please email me
at; kur.kzak@gmail.com
I tried changing my blog personal data to the new email
address and was denied. WTF?
If I can't resolve that issue I'll have to change emails again.
Gee, Google Blog and Google Email together sounded like a
Good idea at the time.

I also aquired a cell phone again after doing without one for
about 7 years and not missing it most of the time.
Thanks K&S.

Campitch 1 Monocopter Pt 3

A good ascent. Note wing gap.

Takeoff. Sign of an inadequate flybar.
1 ft up and already 1 ft sideways.

The wreckage.

The Campitch 1 is no more.

It made 10 flight attempts in 10 months.
Four flights were considered OK, one was very good,
and only one was nearly perfect. One way or another
it tossed it's wing four times. It tore up one part  or
another of the cam system four times, and broke one
flybar. The final flight did all three at once.

Even the best flight bent the cam follower bolt.  It
was the ninth flight and I used one of my 24mm E  
sugar moonburners.  It ascended to around 60 feet, it's
highest flight, and when it coasted about halfway down
it finally slowed enough to retract the wing into full
autorotation mode.   D motors never gave it the needed
height to do this.

On the tenth flight, I used an Aerotech E11J. At about
the 40ft mark, still under power it disintegrated. The
flybar was broken and the cam follower bolt was half
torn from the wing root, and the bolthead was pulled
through the G10 fiberglass cam track.

This spinny thang taught me more than all my previous
monocopters put together.

The biggest problem the CP1 had was it's pretty wing.
Being fully glassed it was too heavy [especially with
balance weight added to the leading edge], and that
eliptical wingtip made it too slick. Together this
gave it a higher than average rpm AND a tendency to
not slow down anytime soon.
Again, because of the wing weight, the unweighted
3/16" flybar used on the first five flights lacked authority.
This caused the motor and wing to pick their own pitch
angle and for the monocopter as a whole to squirrel
around and track at odd angles instead of going straight
up. The second flybar was 1/4" diameter and slightly
longer, but it had so much drag  altitude was reduced
by half.
The wing retract spring is always an issue. If it's too
heavy; it takes extra rpm to extend for takeoff.
If it's too light; it has to slow more to retract into
auto rotation. I used springs because I had a pile to
pick from. A better solution would be rubberbands
which might be easier to fine tune.
Finally, 1/8" pultruded carbon tubing it totally
unsuitable for D+ powered monocopters.  I managed
to break them outright 4 times, in three different
applications.

I'll spare y'all the flight log.
Yahoo Monocopter Group won't be so lucky.