AutoKAP - Still Dreaming

Ok, so the AuRiCo wasn't utterly painless to get running. I built out the new battery pack for it this evening, and gave it a go just by moving my servos over to the new controller. No dice. For starters it rotates the shutter servo the opposite direction, the tilt servo kept losing position, and things generally went to pot.

My guess is the 3xAAA battery pack is simply too skimpy for driving a PIC microcontroller and three servos. SHOOT! So now I'm considering whether I roll my own using an AVR (I don't really do PICs) or whether I get another BBKK from Brooks and build out an AutoKAP rig from scratch.

More and more I'm thinking my best bet is to build out one of Ben Peoples's controllers, which uses an AVR at the KAP end, and a second one on the controller. XBee or XBee Pro radios connect the two, allowing remote operation of the rig. If the ground-side controller is turned off, the rig goes into AutoKAP mode and drives the rig itself. No second rig, no reconfigure, just turn off the ground-side unit and away you go.

So Mauna Kea aerial photography waits. But meanwhile I'm planning on taking my rokkaku to Waipi`o Valley tomorrow to try my luck. Hoping for fair winds and good photography!

Tom

Privacy to Tic

I don't think I've mentioned it here, but I have TS. It's not that I'm shy about it. It's just not something I spend my days pondering, so when I find time to jot something down it's not at the fore. Today it is.

I tried to fly kites at lunch, but the gusts were really too high for the rokkaku. So I reached into my back for my Flowform 16 and... Oh drat. I left it at home. I tried flying the 8 with 15' of fuzzy tail on it to steer me through the gusts, but it wasn't really what I was after. Besides, I finally figured out how to photograph this remarkable weathered building with a rusted tin roof, and the 8 just wasn't providing enough lift to put a camera on the line. So I packed up my gear and actually went to eat something. (What an odd occupation to have at lunch time!)

And that's when the tics started. No real surprise. I tend to suppress them until I have a private moment, and then they happen with a vengeance. I work in an office, so I actually have a fair number of private moments during the day. Besides, this time I was standing in the middle of a field, with no one for a hundred yards! You don't get much more private than that.

So I went to lunch anyway, ticcing the whole time.

For the most part people really don't notice, or at least they don't comment. Most of my motor tics are pretty subtle. For example, how many people can tell if someone's abdominal muscles are constantly contracting over and over and over? If they're wearing a shirt (and I do), chances are a bystander wouldn't even notice.

But while I was ordering I wound up with my full-blown shoulder/arm/neck/face/eyes dystonic tic, and couldn't shake the thing for a number of seconds. And then it happened again. And again. And again.

The folks at the place where I was getting food are too nice to comment, and too friendly to do anything that would hurt my feelings. But it wasn't exactly subtle, and for the first time in a long time I really just wanted a private place to go off and tic without a bunch of people watching. Full-body dystonics can make you look like you're a crazy person. To someone who's not used to them, they can look scary. Seeing that look in someone's eyes as they stare at you just makes me sad. And tired. I just wanted to go off somewhere by myself and tic. Instead I sat down and ate my lunch.

It all stopped a while later, and now I'm back to the normal running-theme tics: bunny-nose, abdominals, snuffing, etc. The ones no one sees, or don't notice if they do.

Tomorrow I'm packing my Flowform 16. If the weather holds I might get a chance to photograph that building, and maybe this time I can tic in private.


Tom

New Kite & New Controller

I got out with my new 6' rokkaku every day this last weekend. Mygawdz what a beautiful flyer! It's steady, it tracks very symmetrically, and it lifts gently enough not to feel like I'm holding onto a truck. I had one almost bad flight where a thermal collapsed and nearly dropped my kite and camera rig into a kiawe tree (think 40 foot high thorn bush). But I got lucky and was able to recover everything. My line still needs a thorough inspection, but I have 1000m of #200 line in a spool in my closet. I'm not sweating it.

Saturday morning I placed an order for an AuRiCo from Brooks's web site. The AuRiCo is an Automatic Rig Controller. You plug your tilt, pan, and shutter servos into it, and it controls the camera rig, taking pictures and rotating the various axes as you tell it to. Today the AuRiCo showed up in my mailbox, only three days after I ordered it. Brooks, I still don't know how you do that, but I'm happy you can! I need to double-check my battery's output voltage to make sure I don't fry the AuRiCo, but I think I should be able to have it mounted and working by this weekend.

I hope to make two flights with the AuRiCo. The first is at the summit of Mauna Kea. The Office of Mauna Kea Management gave me permission to do this a while ago, provided none of the images are used for commercial purposes, and provided I don't interrupt any observatory operations. I'll be careful!

The second flight is still in the dreaming phase: The humpback whales are here again, and I'd like to be able to go out on a boat and fly a kite over them. I've been warned by enough people that soft kites are tough to use on boats (Flowforms are out) and that kites with long bridle lines are also difficult to use (rokkaku is out, too). Which means I don't have a kite for this venture yet. I've also been told that radio rigs are difficult to use from a low-slung boat, and that dunking your transmitter is a very real risk. So I wanted to use the AuRiCo to drive the camera. If I manage to pull this off, I'll be pleased as punch. 'Till then, I'll happily fly on Mauna Kea.

On another note, I'm apparently just as boring as I'd guessed. No comments to my last post. So I don't think anyone other than me reads this. Ah well. Maybe I shouldn't quit my day job.

Tom

I Conclude: I Am Boring

I'm not grousing. Far be it. Truth be told I'm smiling as I write this. But I have come to the conclusion that I'm boring. I don't know how many posts I've made, and I have zero comments from anyone. So what other conclusion can I draw? All the evidence points to it: I'm the only one who reads what I write.

Ah well. In a way it's no big disappointment. I'm writing this more as a personal journal than as any sort of "message". After all, I don't write about much that's profound. Kites? Photography? Machining? Robotics? These are all my interests and how I choose to spend my time. It would be arrogant indeed if I thought others should share my interests. So it really doesn't surprise me that no one appears to be reading what I write. As I'm fond of saying, it's all good.

But if you are reading this, do me a favor and drop me a line so I know. (And if you have any really stable kites to suggest for high wind, let me know!)

Thanks!

Tom

First Flight

My friend did indeed finish the sail last night, except for the grommets where the bridle attaches to the spreaders. We had meetings all day today at work, so I brought all the bits and pieces in, and built the frame in between meeting sessions. The bridle came after we stopped for lunch. By the time lunch was done I was able to walk backward with the rokkaku on the front lawn and actually watch it fly. Gary Engvalls gives very good starting points for spreader bow and bridle adjustment. It flew great the first time!

Since people more or less scattered after the meetings were done, I grabbed my gear and headed out to the park. There was no wind, but I figured I could get some time in just walking backward and tuning. I used my #90 line, figuring I wouldn't walk backward fast enough to cause problems with that. I was, of course, wrong.

Kona winds picked up slightly, but it was enough to get airborne. Then things started shifting, and finally I wound up flying in tradewinds. When I heard the trees behind me start to rustle, I knew I was in for a ride. The rokkaku went almost straight up with the increased wind speed, and the pull on the line was enough to make me take it down. A quick walk back to the car let me switch to #200 line and re-launch.

But the trades were there to stay, and were increasing in strength. I couldn't get the kite down! In desperation I wound up clipping off to my car using one of my new carabiners I got from REI (yay!) and used a second one to walk the kite down. It pulled like a truck right up until it was on the ground.

I learned a lot. Lesson 1 was that the kite may have a wide wind range, but any given tuning doesn't. If the wind changes it can develop a huge amount of pull in a very short amount of time. Lesson 2 was that the kite will fly in almost no wind at all, and since it pulls almost straight up, I figure if it can fly it can lift my rig. (I'm waiting on flying the rig until I can characterize the kite over several flying sessions in different wind conditions.)

Lesson 3 is that I'm in love with the thing. It's a fantastic kite, and I'm more than happy to add it to my kite collection.

There's a catch, however. I thought (THOUGHT!) I'd waited long enough for the CA glue to set when I installed the ferrules in the center sections of each of the spars. I wound up with the spreader's center sections attached to one or the other arm of the spreader, and I wound up with a spine that couldn't be disassembled at all. So the kite, when collapsed, is six feet long. Unless I build out another frame for it I'm not taking it on any airplanes! But it fits in my Jeep with room to spare, and should be able to go to any and all of the places I fly.

On another note I picked up an AuRiCo from Brooks. This is a neat little board that lets you convert a radio controlled KAP rig to autoKAP. A step backward? Maybe not. AuRiCo is flexible enough to handle anything from a "point straight down and bang out a shot every seconds" to "rotate 30 degrees at a time with a level horizon until you've made a full circle, then tilt down N degrees and repeat." So the AuRiCo is my gateway to flying on Mauna Kea where radios are not allowed (they interfere with the radio telescopes) to flying a rig from a boat to take pictures of whales. It should open up a whole new aspect of KAP!

So it's been a good week. I have a kite that will fly in places and conditions where my Flowforms can't, and I should get a care package from Brooks soon that should let me take pictures in places my radio rig can't operate. Can't beat it!

I'm looking forward to a good weekend of kiting and KAPing.

Tom

Welcome to the Rok

"The Rock" is hardly my favorite movie, but that one line is pretty useful at times. In this instance I'm referring to a new kite a friend is making for me, a 6' rokkaku. She's following plans from Gary Engvalls's site with a lot of additional photographic material from various kite makers and fliers around the world. (Thanks, Google Images!)

I bought all the bits and pieces from Kitebuilder.com, including the fabric, the bridle line, grommets, webbing, spars, basically everything. I got to see the sail for the first time today, and it's beautiful! Even having looked at pictures and diagrams online, I wasn't prepared for the size of the thing. It's 72" tall, 60" wide, and a total of 23.5 sq ft of area. Considering my largest kite at the moment is a Flowform 16, this is a big step up for me!

But it's a step in the right direction. Flowforms typically have line angles on the order of 40-50 degrees, give or take. The bridle can't be adjusted to give different angles of attack, so this is a feature of the kite that's fixed. I adjust the line angle on my Flowforms by adding or removing tails. More tail produces a lower line angle. Less tail produces a higher one. No tail makes for a line angle in the 50 degree region, but it's typically not stable enough that I'd trust a camera to it.

This limits what subjects I can photograph, though. Waipi`o valley on the Hamakua Coast is a gorgeous place, with lush taro farms and huge ironwood trees lining the black sand beach. It's also a great place to get a steady onshore breeze, and should be the perfect spot for KAP. But the trees are close enough to the water that a Flowform can't fly there without risking a tangle in one of the tree tops. I've flown there only one time, and vowed not to risk my kites again.

A rokkaku, on the other hand, has a much higher line angle and allows for bridle adjustments. It's a sparred kite where the Flowform is not, and also allows for adjustments to lines that put an induced bow into the spars. The combination of adjustments let it fly in a wide range of winds at a fairly wide range of line angles. Perfect for flying in Waipi`o and Pololu, two beaches with ironwood trees. And the larger sail area makes it perfect for flying in Kona where wind tends to be a little light.

There's one other benefit to a higher line angle: If a kite's line is horizontal to the ground, you essentially need infinite tension on the line in order to lift a one pound camera rig. If a kite's line is completely vertical, you need only one pound of tension on the line in order to lift a one pound camera rig. The higher your line angle, the less pull you need to lift the same rig. So with the larger sail area (23 sq ft as opposed to 16) and with the higher line angle, I can basically lift my rig in almost any flyable wind now.

I'm stoked!

My friend says she can likely finish the sail tonight. That means I need to cut, square, and finish the spars, make end caps, make the kite's bridle, make bow tension lines, put grommets where the bridle will poke through, etc. I may be able to fly it tomorrow afternoon, good wind willing!

Can't beat it...

Tom

The Nature of Wind

If you look in practically any high school text book, wind is said to arise from solar heating causing an updraft, which results in convective flow. Other mechanisms may be mentioned in passing, but one that's often overlooked entirely is the coriolis effect, or the differential rotation rates at different latitudes on the surface of the planet.

What's truly odd is that this is not some obscure effect that only generates small localized wind patterns in faraway reaches of the Earth. Coriolis-generated wind patterns are some of the largest on the planet. Better known as the Tradewinds, they are directly responsible for trans-oceanic travel by sail. They are also the major component of the weather patterns on Jupiter, Saturn, Neptune, and Uranus. No small thing.

As it turns out, it's also the main driving force of the wind where I live. Wind can either be described as "blowing trades" or "blowing Konas". The former is the predominant wind pattern, whereas the latter is almost always the case when a storm is involved.

All of this makes kite flying wonderfully predictable, if you're in an area of clear air. If it's blowing trades, it's blowing trades. If you're solid at 200' above ground, you'll be solid at 500' above ground. And unless there's a storm brewing that's likely to change things, you'll still be just as solid six hours later.

Oh what a wonderful place to learn to fly kites!

So when I visited the Mainland in December, I brought my KAP rig, my kites, and everything that goes with them. There was even wind! Heaven! But wait a sec... the wind shifts 90 degrees when I'm 300' above ground, and does another shift 200' above that. Then as I'm winding back in, the ground layer shifts 90 degrees and the uppers don't change at all. WHAT?! Then the uppers die, but the lowers are screaming so hard I can't get the kite down. ARGH!

All this tells me that maybe I should've paid more attention to the description in my high school text book!

Of course I'm over-simplifying the winds where I live, and I'm over-complicating the winds on the Mainland. But not by much. We do get convective wind patterns where I live. (Physics doesn't stop working just because you live on an island.) Those, too, are nicely predictable because the updrafts tend to center around recent lava flows where the ground is a wonderful matte black. If it's party cloudy the patterns can get rough because of the patchy sunlight, but the directions are all predictable.

It's less-so where I flew on the Mainland. In the three weeks I was there, I saw wind come from every point of the compass, sometimes all in the same day. I was afraid to leave a kite unattended, even for a few seconds, and wound up with hands on the line the entire time. I still treed my kite twice. It was a whole different kind of flying.

Today I flew a kite for the first time since getting back. It's blowing Konas, so the winds are backward, but they're predictable. No KAP since the wind wasn't consistent enough for me to hook up my rig. But I spent a really pleasant few hours just flying and feeling the wind out.

It's good to be home.

Tom

Vacations: Purpose?

My wife bought our first serious camera in 1995: a Canon A2 with a 35-135mm lens. Over time more bodies and lenses came along, as well as several tripods. We even branched out in to large format photography with 4x5 gear. In the end we became fairly competent photographers, and had a purpose for our vacations: photography!

A typical day had us picking a location, throwing on way too much weight in gear, hiking around all day, and dragging our sorry looking selves back some time after dark with a couple of rolls of film shot, an exposed set of film holders, and big grins on our faces. But it didn't involve a lot of talking or visiting with other people, and to be painfully honest when other people were involved we did a lot less photography.

Recently, I got into kite aerial photography (KAP). When we decided to go to the mainland for vacation, my wife packed our camera gear and I packed my KAP gear. It was going to be great!

But after three weeks of vacation, I realized I only had one good flight and most of our pictures are of people. It wasn't for lack of wind or subjects. On the contrary the wind was remarkably good for that time of year, and my list of subjects was longer than my arm. But we had a choice: Are we here to do KAP? To do photography? Or are we here to visit with people we haven't seen in five years? The people won.

This phenomenon isn't limited to photographers and KAPers. It applies equally well to anyone else with a hobby that can be fed while on vacation. How many history buffs, sports buffs, fossil buffs, etc. ruin their family vacations by insisting they drag everyone to place X to see thing Y? And how many more wind up hating their family vacations because their family won't let them?

Let's face it: To an outsider, spending two hours crawling around under sage brush with a camera and a blacklight chasing scorpions is no less aberrant than insisting on visiting every civil war battlefield between Natches and Alexandria. So which is it going to be? Hobby? Or people?

So in the future I'm making a conscious choice: If it's going to be a KAP trip, I'll pack KAP gear with the understanding that I will be using it at the expense of doing other things. If it's going to be a photography trip, we're bringing both tripods, the 4x5 bag, the DSLR bag, etc. But if it's going to be a people trip the KAP and photo gear stay home.

But please bear with me if I'm still looking for wind sign and my wife is still composing shots.

Tom

Vacation

I just got back from a three week vacation. Lots happened, lots didn't. I started off homesick for the place I was visiting (where I grew up) and wound up homesick for the place I'd left. So all in all it was a good trip. Too much happened to put into a single post, so I'm writing them up separately as time allows.

Tom