The Coolest Thing *EVER*

Formation RC Flying

This is a video of my seawind flying in formation with a small fishing boat.  The boat was running flat out while I was holding the aircraft on the edge of stall.  There was barely any wind that day so we were able to do several out and backs.  If you’ve never flown from a moving platform, let me just say it is really weird and really easy to let the aircraft get way far away from you.  Videography credits (if there are any) 🙂 go to my Mom.



Building Openembedded for Overo on Fedora 14

Building Openembedded from scratch

The primary build instructions for building openembedded for the Overo processor can be found on the gumstix.org web site here:

http://www.gumstix.org/software-development/open-embedded/61-using-the-open-embedded-build-system.html

Fedora 14 Specific Fixes

Follow the instructions at the above link.  However, there are several places where the standard openembedded build breaks.  Here are the Fedora 14 specific problems I encountered with specific fixes and work arounds.  This is a moving target so if you run into new issues, feel free to let me know and I’ll update this page.  In all these cases I found solutions by googling, so if you have encountered something not mentioned here, google is your friend!

module-init-tools

Error in module-init-tools:

/usr/bin/ld: cannot find -lc

Solution:

yum install glibc-static (on the host system)

patch: **** rejecting target file name with “..” component

Error in patch (occurs in many places):

patch: **** rejecting target file name with “..” component: ../generic/tclStrToD.c

Solution:

As of 17th March 2011 if you have patch-2.6.1.-8.fc14 installed you may need to downgrade to an older version if you are getting patch errors during your build. To downgrade:

# yum downgrade patch

Note: pending a better solution, this will get you by … (as of April 12)

docbook build error …

Problem:

docbook.org changed the link to their source file

Solution:

$ cp ${base}/org.openembedded.dev/recipes/docbook-sgml-dtd/docbook-sgml-dtd-native.inc{,.orig}

$ edit ${base}/org.openembedded.dev/recipes/docbook-sgml-dtd/docbook-sgml-dtd-native.inc

Add the following two lines:

SRC_URI = “http://www.docbook.org/sgml/${DTD_VERSION}/docbook-${DTD_VERSION}.zip”

S = “${WORKDIR}”

And delete the following line.

SRC_URI = “http://www.docbook.org/sgml/${DTD_VERSION}/docbook-${DTD_VERSION}.zip;subdir=${BPN}-${PV}”

Finish building the main images with

$ bitbake omap3-console-image

Building MLO-overo

After the omap3-console-image is finished there is still one missing piece: “MLO-overo”.  To build this, run:

$ bitbake x-load

All the generated images will be found in:

${overo_root}/tmp/deploy/glibc/images/overo

Uploading your new images to the Overo

  1. Follow these instructions to Create a bootable microSD card article.
  2. Follow the instructions here to copy the images to your SD card and then to the Overo flash:  http://www.gumstix.org/how-to/70-writing-images-to-flash.html

Stay tuned … 🙂

 

North Pacific Ocean Sunsets


Being out on the open ocean is an awe inspiring experience.  The ocean is incredibly powerful and unforgiving.  The wind and waves are relentless.  The sunsets are the most incredible of any place I’ve ever been.  This is my collection from a NOAA research cruise through the Pacific straight north of the Hawaiian Islands:

 

 

North Pacific Debris Gallery

NOAA Debris Research Cruise

In the spring of 2008 I joined the ATI team on a NOAA research cruise into the “North Pacific Gyre”, AKA “North Pacific Garbage Patch” — an area north of Hawaii the size of Texas where floating plastic debris collects.  Plastic can break into smaller chunks but it doesn’t really decompose, or it degrades so slowly that it is accumulating much faster than it is disappearing.  This leads to an increasing colleciton of junk and garbage on the surface of our oceans and is an ecological problem.  I’ll leave it to others to debate the magnitude of the problem, but from a personal perspective, being out there myself and seeing the amount of junk, I was greatly saddened. It’s a big mess that is almost impossible to clean up, and it’s in a remote area that most people do not see.

There were many fascinating, exciting, and challenging aspects to this trip, but here I am simply displaying my picture collection of North Pacific Gyre Junk.

Tracking Ocean Debris in the North Pacific

The Search

On April 2, 2008 I found myself on a 224′ NOAA research ship, the Oscar Sette.  We were sailing about 1000nm north of Hawaii in the middle of the Pacific Ocean. This was day 10 of a nearly 3 week cruise.  Our mission was research. The task for the day was to search for debris. We had entered the North Pacific Gyre two days earlier. This is often called the “garbage patch”. A debris field of floating plastic junk the size of Texas.  It is made up of human generated plastic waste that never really decomposes, instead it very slowly breaks up into smaller and smaller chunks.

A Spotter Sees Something!

Early in the afternoon, the call went out. One of our spotters saw something, and it was much bigger than the ordinary floats and chunks of plastic we had been seeing.  We turned the ship towards the object.  When we pulled up closer we discovered it was a houser line — a giant rope used to secure large ships.

Retreival

When we were close enough, one of the crew members snagged the line.  We hooked it to a hoist and carefully pulled it on board.

The Release

We then attached an ATI gps tracking buoy to the rope and set it free.  The decision was made that the research value of observing the drift of this debris through the ocean currents was higher than simply removing the object from the ocean.  The deck crew then lowered the tangle of rope back into the water and set it free.  Here  you can see it drifting away with the buoy attached (the solar panels at the top just peek above the water line.)

This was THREE years ago now and the buoy is still alive and reporting it’s position twice a day.  Aren’t you curious where it’s been?!?

Drifting through the North Pacific

The following video shows an animation of the ATI tracking buoy on it’s three year journey.

I think this is incredibly fascinating to watch, and the buoy continues to send position updates twice a day, each and every day.  It has solar battery chargers so it could survive a few more years with a little luck.

Check the latest progress of buoy 15FXZ

As of this posting, buoy 15FXZ is still alive and well and drifting around the ocean. You can check up on it’s latest movements anytime by clicking on the following link:
http://www.atiak.com/buoy_maps/
At the top of the map is a drop down menu. Select 15FXZ (should be the very last entry, you might have to scroll), pick a date range if you like, and click “Go”!

Conditions at Sea

It is difficult to capture the magnitude and power of the ocean in pictures.  The waves always somehow look smaller and less impressive through a camera.  I took some video footage while the houser line was pulled up on deck.  You can see the wind, the spray, and how much the ship pitches up and down in the waves.  If you’ve never been out in these conditions, they are pretty typical of the north pacific, but getting tossed around like that 24/7 makes it very difficult to do anything.

Launching Update

Update on MiG-15 Launching Technique

Here is a launch tip for anyone who’s struggled to get the Hobby Lobby MiG-15 airborne reliably:

First, recognize that at FULL throttle, there is a small tendency to want to pitch up (probably due to the large mid-T tail configuration more than thrust lines.

Second, recognize that this is not a prop plane so there is no prop wash flowing over the control surfaces. All control surface effectiveness is due purely to forward speed. During a hand launch, forward speed is at it’s slowest and control surface effectiveness is at it’s lowest.

The problem: At full throttle and very slow speeds, the tendency to nose up is stronger than the control surface effectiveness, so right after the aircraft is thrown, even with full down elevator you may not be able to overcome the nose up force of the motor. This leads to the aircraft floundering … the full thrust is pushing the nose up, keeping a high angle of attack, and forcing slow flight speeds. The control surfaces can’t compensate due to slow flight speeds and no prop wash to help out. You can’t push the nose down, you never begin to accelerate, and often the flight ends after a few seconds as the aircraft stalls/flops/cartwheels in.

The solution: Launch at 2/3 to 3/4 throttle. (Basically keep the throttle as slow as you dare on launch.) Throw the aircraft level or even on a slightly nose down trajectory. This reduces the tendency to nose up, allows gravity to help accelerate the aircraft a bit, and allows the aircraft to accelerate naturally, and fly off as expected.

The launch problems with the MiG-15 are EXTREMELY frustrating, but once you get your launches dialed in, this little bird is a blast and really performs well! One final tip: this MiG does have a nasty spin if you manage to stall it. I try to hold at least 1/3 to 1/2 throttle through my turns and I’m careful not to pull too hard on the elevator. Let the plane fly itself, keep your control inputs light and you should have no trouble staying above stall/snap speed.

Hobby Lobby P-47

Introduction

Hobby Lobby recently introduced a neat P-47 warbird model.  It has a 40″ wing span, 4-channel flight control, retractable landing gear, and comes receiver ready.  It includes servos, motor, speed control, and even a suitable battery.  All you have to do is some basic assembly, install your receiver, and you are pretty much ready to go.

Construction

Here are the tail surfaces as they come out of the box.  Everything is pre-hinged.

Here is the fuselage as it comes.  The motor and speed controller are already installed.  Servos and linkages are installed.  Even the cowl comes pre-installed:

Here is the wing.  As you can see, the two halves are already attached.  The landing gear and retract system is already installed.  The servos and linkages are also installed and the control surfaces are hinged and attached.  The wing flaps are not operable by default, but I noticed there are servo mounts molded into the wing and it would be a 30 second job to cut the wing flaps loose and hinge them.  So if anyone really wanted to add flaps for additional realism, it should be a straightforward mod.  The aircraft definitely doesn’t need them though … it slows way up if you want it to and flies very stably at slow speeds.

Here is a close up of the machine guns on one side.  There are tons of little details built into this aircraft!

The prop was a neat surprise.  It’s an operational, scale, 4 bladed prop.  The prop tips are painted yellow and it really looks neat when it is stopped and when it is spinning.  It includes a scale prop hub and the final result looks really sharp!  I’m sure the prop is not the most efficent choice, but it looks great, and works great so I’ll run with it.

After hardly any effort or time, I ran out of things to do and the aircraft was done.  It’s midnight though so I took it out in my driveway for a pre-maiden photo shoot.  She really looks sweet.

Here is a good view of the business end.  You can see the scale prop and the retract system.  Very nice!

… time passes …

The next day after I finished the airplane we got a giant snow storm here in Minnesota.  Blast!  I figured it was still late fall, wait a few days and this first snow fall of the season would melt.  But unfortunately, mother nature had other plans for us.  The temperatures dropped, more snow came, and more, and more.  The RC club field was buried for the winter. 🙁

Fast forward to April.  The snow has finally mostly melted and the road to the field has dried out enough to be passable with normal street vehicles.

The Maiden Flight

I snuck out to the flying field for an early lunch break.  The winds were relatively light @ 5-10 mph.  But they were at a 45 degree cross wind though which was the only minor complication.

Here are some pictures before the first flight.  I also have a battle tested Hobby Lobby MiG-15 that uses pretty much the same battery so I brought it out as my “backup” airplane in case I found a problem with the P-47 and couldn’t fly it.  I hate wasted trips to the flying field!

She’s just as pretty in the grass in the morning as in my driveway at midnight. 🙂

Maidening a new airplane can get the butterflies going, so I always try to tell myself that these things are designed to fly.  They want to fly!  It will fly great!  And that’s the truth.  I had to dial in several clicks of right aileron and a couple clicks of up elevator and I was grooving around the sky.  The scale prop doesn’t offer blazing top end speed, but it’s solid and gives good power.  There is plenty of HP to climb very agressively.

Retracts!

I’m especially excited about this P-47 because it is my very first RC model airplane with retractable landing gear.  A WW-II warbird really needs retractable gear.  It just doesn’t look right flying around with the gear down, and if you build it with no gear at all, then you have to hand launch and belly it it.  The retracts worked great with two lessons learned:

  • I mentioned earlier I had quite a significant cross wind.  On my very first landing I mismanaged my rudder and my slip and touched down with quite a bit of side load.  This collapse the upwind gear leg and I skidded to a stop.  Dohhh!!!  That left a couple scratches on the bottom of the aircraft, but didn’t seem to damage the gear (it just popped right back out when I picked up the airplane) and the big scale prop was safe too.
  • On the second hop, the retracts suddenly stopped working.  Fortunately they were stuck down.  I landed, this time being much more careful with my cross wind technique and inspected the gear.  In my lap, the retracts worked perfectly.  I took off and still couldn’t get them to retract in the air.  Then I took a quick cheat peek at my hands and realized I was trying to toggle the wrong switch.  Dohh!!!  That’s what I get for buying a 7 channel transmitter with about 20 levers and knobs and switches on it.  Once I found the right switch the gear worked perfectly again. 🙂

Nose Overs

I read online that this design has a tendency to nose over and guys were busting up their scale props (and then complaining because they were out of stock.)  So in my test flights I was very careful to hold up elevator at the start of the take off run and touch down with a heavy dose of elevator dialed in.  By the way, this P-47 has awesome slow flight characteristics.  If you are careful to bleed off your speed and flair at the right time, this thing totally slows down to a walk and drops in for a nice 3-point landing.  I need more practice, but on a nice light wind day, I think there’s potential for some really really sweet landings.

Wing Crack

After my first battery was expired, I picked up the aircraft to walk back to the pits.  I noticed a crack developing in the wing foam on the bottom side of the wing, close to the wing root between the leading edge and the wheel well on the right side.  The spar was solid, but there was more flex there than I liked to see.  Bummer, done after one battery, but still happy with how things went.  I’ll file this under “shaking out the bugs”.  Hopefully a little glue will secure the foam and I won’t have any more problems.  It’s something to watch though. Update: the crack was a little more extensive than I first thought … it appears to be from landing, but I don’t recall banging it in real hard. Oh well, I glued it together and hopefully it will hold.