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SPIE 2016 – Manuscript (almost) In The Bag! / World Wide KAP Week 2016 / Visitors

Posted by Tom Benedict on 20/05/2016

Manuscripts for the 2016 SPIE Astronomical Telescopes and Instrumentation Conference are due May 30th, so a little over a week off. With my usual level of good planning I didn’t associate that date with a visit from my friend and his wife (May 27th-29th) or the dates for World Wide KAP Week 2016 (May 13th-22nd). So no, of course I didn’t get an early start on things! I left things ’till this week. >sigh<

But I think I’ve got a workable rev of my manuscript in the bag. The graphs took a while to sort out, but everything came together this afternoon. I still have at least one round of editing left to go, but at this point it doesn’t have to occupy my every waking moment.

I think I avoided impacting my friend’s trip, and I still have this weekend for WWKW. Not ideal, but not a complete loss, either. I’m picking out a couple of subjects for WWKW, and tonight I’m going home to clear my chips and charge my batteries. Kite flying and kite photography, here I come!!



Posted in Astronomy, Kite Aerial Photography | Leave a Comment »

Olson Wing and Damped Pendulum Suspension

Posted by Tom Benedict on 24/09/2015

One of the earliest experiments I did with aerial sound was to pop a windjammer on my Tascam DR-05, bolt it into my KAP rig, and send it aloft. I learned a couple of things from that flight: KAP electronics cause gobs of EM/RF intererence, servo jitter is incredibly loud, and the PeKaBe blocks in the Picavet suspension never ever stop making noise. I decided to solve all three problems by skipping the Picavet, using a pendulum, and losing the servos and electronics altogether.

I’ve wanted to built a damped pendulum KAP suspension for a while. My earlier designs involved a parallelogram section with four pivots and a straight section with a single pivot to minimize swing from changes in wind speed. I still think that design has a lot of promise and I’d eventually like to get back to it. For this, though, I only built a single straight section with a single pivot. It’s the easiest way to start playing with pendulum suspensions, and will let me figure out what the real design issues are. The pendulum I built has a pivot faced with a pair of 1-1/4″ disks of metal. I lapped the two plates together and filled the gap with Nye damping grease. The resulting joint is very quiet, smooth, and damps motion. There’s not as much damping force as I’d like, but that’s why it’s a prototype. I’m experimenting! As with any KAP project, as I was putting the finishing touches on the pendulum and loading the pivot with damping grease, the clouds opened up started to rain. So testing will have to wait.

Damped Pendulum Suspension

The other project I finished over the weekend was an Olson Wing microphone array, based entirely off of work by Curt Olson. Since the intent is to fly this from a kite I designed in wind protection from the get-go. The Olson Wing has an upward component to its sensitivity, so I built a 30 degree triangle into the back to angle the mics and baffles toward the source. Both legs of the triangle have 1/4″-20 threaded sockets in them. One allows me to use it on the ground, and aims the array for horizontal use. The other allows me to use it from the air, and orients it for downward vertical use. In both cases the range of motion from the tripod heads let me aim it in any number of directions. Unfortunately the photos I made of the Olson Wing looked horrible, so I’ll have to try again at a later date.

I had a little more opportunity to test the Olson Wing than I did the pendulum suspension. Some tests in 8-12kt wind showed that the furry windjammer does indeed work. On the advice of David Brinicombe from the Yahoo! Nature Recordists’ Group I added a 40Hz low cut filter, and almost all the wind noise is taken care of. Ready to fly!

While testing the Olson Wing I discovered something cool with my light stands. Two of them have 3/8″-16 threaded tips, and the other two have 1/4″-20 threaded tips. The 1/4″-20 stands can take the same mini ballhead I use on my photography pole. Depending on the mood, I can’ use them to stick a fixed angle camera 12′ up in the air, or I can bolt my KAP rig upside-down on top using my pole adapter, or I can stick either my SASS or Olson Wing on top and have a very portable self-contained field kit for doing stereo ambient recordings. Or I could use it to hold a light and modifier, the way it was designed. I love finding new uses for existing equipment!

Two other things happened later in the week that are also moving the kite aerial sound project forward. The first was the arrival of my second sound recorder, a Tascam DR-70D. It’s a hefty little brick of a thing, so I don’t think I’ll fly it on a kite any time soon. But it’ll be perfect for recording sound on the ground, including line scream. Which brings me to the other thing I did this week.

Tascam DR-70D

I built a contact microphone. Zach Poff has a nice article on building a contact mic with an impedance matching buffer circuit designed by Alex Rice. You can wire a piezo disk directly into a 1/8″ (3.5mm) microphone plug and plug it into a laptop or a recorder like the DR-05 or DR-70D. But the combination of the low capacitance of the disk and the low impedance of the recorder input effectively results in a high pass filter that cuts sound below a few kilohertz. This is why contact mics have an unfair reputation of sounding tinny. The impedance matching buffer solves this by presenting the piezo element with several megaohms of impedance, and providing an impedance-matched input to the recorder. The mic I built has remarkably good bass response. So far I’ve only played with it by recording things like kettles boiling and sinks running, but it should be a simple matter to attach it to a hoop winder to pick up the sound off of a kite line.

All in all it was a good weekend and a good week. If the weather holds I should be able to test out almost every combination of ground and air recording, as well as recording line scream. By the end of it I hope to have answered most if not all of my outstanding questions about the how-tos of kite aerial sound, and an idea of what I need to pursue it further.

– Tom

Posted in Audio, Kite Aerial Photography | Leave a Comment »

KAS – aka In Over My Head (again)

Posted by Tom Benedict on 15/06/2015

Some years ago I was hot on the idea of launching a high altitude balloon, festooned with cameras I’d used for doing kite aerial photography. I still have some of the bits and pieces from the balloon payload I never built, including a really neat little styrofoam cooler a co-worker was throwing out. In the process I watched a ton of videos from high altitude balloons (HABs), but none of them struck me like one I found from a launch in Florida. Unfortunately I haven’t been able to find this video again, or I’d share it here. What set it apart from the others was the lack of a music sound track. Instead, it used the audio from the camera. What I heard blew me away.

The balloon was launched from a city park. In the video you can hear all the normal sounds of a park: kids playing, dogs barking, the launch team talking amongst themselves. Just after launch you continue to hear these things, but gradually they die out, to be replaced by sounds of nearby traffic. Eventually the traffic dies out, leaving only a siren wailing in the distance. Finally the only sound left is that of an airplane flying well below the balloon, which at that point is over 50,000′ above the ground. After that, nothing.

I never did build a HAB of my own, but that video made me fall in love with the idea of recording sound from the air. I tried using the microphones on my KAP cameras, but the on-camera audio, even on a camera like a Canon T2i, is pretty poor. The microphones are tiny, the sound is hissy, there’ s no wind protection, and the T2i has automatic gain control you can’t turn off. (Later models like the T5i have this as a menu setting. Good move, Canon!) A few years later when I got into doing video on the ground with my T2i, I got a separate audio recorder for just this reason. It didn’t take long before I flew the recorder on a kite, but the sound still wasn’t great. No fault of the recorder, mind you. It worked perfectly. But I could hear the rig servos, the Picavet pulleys, line sing, and everything else going on on the KAP rig. I gave it up as a bad idea until I could think about it more.

So I thought about it. And I researched it. And I started learning the intricacies of field recording. I hit on Paul Virostek’s blog and bought a copy of his first book, “Field Recording: From Research to Wrap”. If you’re interested in sound and field recording, I highly recommend Paul’s book. He doesn’t start with the assumption that you have to own the latest, greatest, most expensive equipment. He starts with the assumption that you want to record sound. It’s a good place to start.

I haven’t had a lot of time to pursue my hobbies recently. I spent the last nine days painting and re-flooring my house, and in all that time I picked up a camera only once: to photograph the new floor. But Saturday morning I found myself in Kailua-Kona with time on my hands before my next appointment. “Aha!” I thought, “I’ll go record the surf at the Old Airport Park!” I grabbed my field recording gear and headed that way.

What followed was a comedy of errors worthy of a Marx Brothers movie. I set up to record surf, only to hear a persistent helicopter sound. I looked up to see a whole slew of skydivers with US Army canopies, and a Chinook flying overhead. The skydivers were landing in the park. One of the points Paul makes over and over in his book is that field recordists need to approach things in terms of serendipity rather than ruined opportunity. I couldn’t record the surf because of the helicopter, but I could record a helicopter!

I ran over to the landing area in time to catch it. But the mics on my little field recorder were overwhelmed. By the time I’d dumped the gain enough not to clip, the helicopter had landed and the event was over. I stuck around for takeoff, only to find I’d accidentally paused the recording until the helicopter was out of range.

So I went back to the surf, only to find the skydivers had jumped again, and the Chinook was coming back down. Back to the landing field!

This time I got a better recording of the helicopter, but the crowd noise was a little overwhelming and I still clipped. I got a good recording of the takeoff, though. Back to the surf!

I finally got a good surf sequence, but at the tail end a large set of waves came in and swamped my location. I grabbed my gear before it got splashed, only to have my windjammer fall off the end of my recorder and into the water. It looked like a little floating hairball. I fished it out, rinsed it off, and called it a day of lessons learned. Two days later it’s still damp. One more lesson learned: don’t let these things get wet!

I’m still a fair way from being ready to try kite aerial sound again, but I’m getting closer. I know what went wrong with my earlier sessions. I  know I want to wire in the audio channel on my video transmitter and set up my ground unit with a headphone jack. I also want to test all my gear in a studio box to see if I’m picking up RF hum from the transmitter. I now have real motivation to change from Picavet to pendulum suspension for the rig. I know I need line dampers to take out line sing, even though the KAP community moved away from them years ago. The list is long.

After that it’s a question of building a KAS rig that’ll give me the aerial sound I want. Right now I’m looking at building a variation of Curt Olson’s Olson Wing using EM-172 capsules, which I found from Zach Poff’s article. I’ve got other supplies from an earlier attempt to build windjammers for a borrowed pair of lavalier mics that should let me cut down the wind noise as well. I’m still not sure what I’ll use all this for, but it should be fun.

– Tom




Posted in Audio, Engineering, Kite, Kite Aerial Photography | 2 Comments »

Frankentransmitter Part 1 – Planning

Posted by Tom Benedict on 28/03/2015

If you haven’t seen a lot of kite aerial photos or posts from me recently it’s because I’ve been categorically spanked the last several times I’ve gone out. If it’s not weather, it’s my gear. If it’s not my gear, it’s my batteries. If it’s not the batteries, it’s just life being a pain in the rear. It’s depressing, so I haven’t been writing about it.

Some time back I decided I wanted to rebuild all of my KAP gear from scratch, but I never got around to it. A couple of things have brought this to the fore on my list of projects. The main one is this recent history of blown KAP sessions. But a second and much more motivating reason is some phenomenal work by Dave Wheeler, a fellow KAPer. Dave built a really beautiful controller he described in the KAP Forum and documented on his project’s Github site. The core of Dave’s transmitter is an Arduino and the RF board out of a HobbyKing 6-channel transmitter – the same transmitter I’ve done KAP with for years. Dave’s transmitter is honestly more than I need for my style of KAP, but now I have no excuses left. Time to design and build the thing.

Before launching into my plans for the new KAP gear, here are all the issues I plan to fix:

Ease of Use – My gear isn’t easy to use. My ground unit consists of an RC transmitter and a wireless video screen. To use them I have to attach them together, then stick a cloverleaf antenna on the video receiver. To pack up at the end of the day I have to reverse the process. I go through a similar process on my KAP rig: attach legs, attach a feedline to the video transmitter, then attach the antenna to the feedline, etc. There are so many steps, it’s easy for something to go wrong. I want to be able to pull an already assembled KAP rig out of my bag, stick a camera on it, pull out my ground unit, and fly. No screws, no plugs, no antennas to install, no nothing. Just pull it out and play.

Flexibility – I have several KAP cameras: Canon T2i, Canon A650IS, Canon A2200 (x2), and a Gopro. Depending on the wind, the subject, my mood, or what have you, I want to be able to fly any one of these. In the case of the A2200 cameras I want to be able to fly both at the same time and do four-color photography. Right now I have to swap tilt brackets when I change from one set of cameras to another. I want to have one tilt bracket that’ll take the camera of my choice without swapping or modification, even if it looks like Swiss cheese.

No Dangly Wires – One of the features the brushless gimbal designers incorporated a while back is either hollow cored motors so wires can pass through each axis, or slip rings so the signals are passed through without wires to twist. With the exception of the shutter cable and video cable, there’s no reason to have any exposed wires on a KAP rig. I’d like to have jacks on the bottom rear edge of the tilt frame so that all camera cabling terminates right there on the tilt frame and doesn’t have to pass from one moving part of the rig to another one. I want to make custom cables for each camera so they’re as short and stout as possible.

Suspension Independent – My current rig has this already, but it’s a feature I want to bring over to the new rig. I want to be able to use a Picavet, a pendulum, or whatever suspension I want without having to rebuild the top end of the rig. I like the system I already developed, so I’ll adapt that to the new rig with few, if any, modifications.

High Badass Quotient – This is a personal thing. I want my gear to look like it was made that way on purpose. My CNC mill is back up and running, including the rotary stage. I’d like to use it for most or all of the parts for the new KAP gear. We’ve been testing some new surface treatments at work, and one stands out for home shop work: Cerakote. It’s a ceramic coating that can be applied in the home shop. The coatings are amazingly durable, really good looking, and stand up to wear and tear better than any paint I’ve ever used. They’re about as durable as good anodizing. Every bit on my rig will be covered in Cerakote. I want Hasselblad to be envious by the time I’m done.

What I want, in the end, is a much smaller, completely self-contained ground unit I can just pull out of my bag, turn on, and use. I want a KAP rig I can pull out of my bag ready to run with no chance of a popped wire, broken connector, missing antenna, etc. I don’t care if I take on another 100g in the process so long as it’s flight ready right out of the bag. I want my KAP bag to come down to a winder, a rig, a ground unit, and the kites of my choice. And everything should just work.

After all, isn’t that what we expect out of every other piece of camera gear we own? That’s what I want for KAP.

The design phase is next.

– Tom

Posted in Engineering, Kite Aerial Photography | Leave a Comment »

I’m Writing Again! YAAAAY!

Posted by Tom Benedict on 15/09/2014

Rydra’s latest procedure went well. We’re still waiting on a follow-up CTA scan, but at this point she should be back on track. Both of us hope this marks the end of a three year stint of medical procedures. And we’re both looking forward to getting back to the things we love doing. For her this includes dancing, hiking, swimming, and enjoying life. For me it includes KAP, among other things.

I’ve been in a KAP dry spell for years, and it’s driven me nuts. To be fair I’ve done some KAP in the last three years, and have taken on a number of KAP-related projects during that time as well. But nothing like it was when I first started. I can’t wait to get back in the swing of things. I seriously can’t wait. And in fact, I didn’t.

Her last procedure took place on another island, so we caught an island hopper flight on Mokulele Airlines. They operate a fleet of single-engine turboprop planes that they fly around 8000′ ASL – higher than your typical KAP flight by 7500′, but a heckuvalot lower than the 35,000′ ASL of the big commercial jets. The view is fantastic. Ooooh yeah, I brought cameras. Lots of cameras. Infrared cameras and visible light cameras. And I pretended we were one super big kite, and I played!

The play had a purpose, though. One KAP project I’ve had on a back-burner for a while is to build a two-camera KAP rig so I can get R,G,B, and I channels for doing vegetation analysis and archaeology. I tried pointing my IR-converted A2200 out the window of the airplane side-by-side with my unconverted A2200. When we got back I tried aligning the images to see what I could do with them. To my delight, it worked! Here’s one pair, combined to look like color infrared film:

South Kohala Color Infrared

Combining the two a different way I got an NDVI image of the same field:

South Kohala NDVI

The cameras weren’t calibrated. I just pointed them out the window and pushed both shutter buttons simultaneously. But hey, it demonstrated that the idea works! I posted these to Flickr and to the KAP Forum, and got busy.

A couple of months ago – the last time I had time to work on this – I modified a spare Brooxes Tilt Frame to hold both the A2200 cameras. The only catch was that one had to sit a little behind the other. But since the subject distance is typically in the hundreds of feet, I figured a difference of one inch is negligible. (The cameras in the Mokulele flight were displaced by inches, and hey, they worked!)

The real trick was modifying my GentLED-CHDK cable to trigger two cameras. Around the same time I made the tilt frame, I emailed James, asking if this was possible. He assured me it was. So I got some right-angle adapter cables on Ebay and… had to drop the whole thing for several months.

Today I pulled everything out, mounted the cameras, cut the cables  to length, soldered everything together, and… Nothing.

I wrote a frantic email to James asking for help, then remembered something: Wire color coding on USB cables is random at best. I rang the cables out and found that Vcc was wired to the red wire (makes sense), but ground was wired to blue. (BLUE?! Really?!) With the correct wires connected, the cable worked fine. I tested one, then two cameras, then put the whole thing together.


The rear camera supplies the video feed to the downlink so I can aim the cameras on the ground. The cameras are functionally identical except for wavelength sensitivity, so I can either have a color or an infrared image on the viewfinder. (Yes, I tested it both ways before flying it!) With everything working, I rushed out to give it a test flight! And… the wind died.

Most KAPers are a little more sophisticated with their kite flying than Charlie Brown, but the spirit of the thing holds true. This is how it is with KAP. As soon as your project is done, the conditions for testing it are terrible. But that’s ok. I’ve waited three years to get back in the saddle. One more day won’t kill me.

– Tom

P.S. Ok, I’m biting my nails! I can’t WAIT!

Posted in Kite Aerial Photography | 1 Comment »

IR KAP with the A2200

Posted by Tom Benedict on 16/06/2014

I finally got out to do some near infrared kite aerial photography with my newly converted A2200. Opportunities came up during the week to fly around town, but I punted on them in favor of returning to my camera proving ground: Anaehoomalu Bay.

Back in 2008 when I replaced my aging Nikon Coolpix 5600 with a Canon Powershot A650IS I tested it in town first. But I really put it through its paces at Anaehoomalu Bay. There are so many different terrains with so much varied texture, it’s a great place to see what a camera can do. Back then the A650 was clearly a step up from my 5600, and the photos at Anaehoomalu Bay really let the camera shine.

Where the Wind Comes from - Panorama

That first session with the A650 was great. So how did my first session with the NIR A2200 go?

In a word, frustrating.

To be fair very little of this was the camera’s fault. This time all the blame is on me. When we got there the wind was very light so I grabbed my 7.5′ rokkaku. By the time we’d hiked to where I wanted to do KAP, though, the wind was blowing. Rather than do the smart thing and walk back to the car for a different kite (or, better yet, the whole kite bag!) I put the 7.5′ rok up anyway. The kite was clearly over-powered. It was iron-bar flying all the way.

Within a few minutes I heard an approaching helicopter. Sometimes tour companies will overfly Anaehoomalu Bay, but nine times out of ten it means County Search and Rescue. These guys routinely fly below 500′, so I started hauling in line as fast as I could. Sure enough the County S&R helicopter came flying out from behind the trees. There are plenty of horror stories of kites and kite lines being hit by low-flying helicopters, but the County S&R pilots are some of the best I’ve ever run into. I’m pretty sure they knew the day I started flying kites at Anaehoomalu Bay and noted every day I flew after that. They flew over, came back, circled my kite once, and took off. The whole time I was taking in line, hoping I didn’t get caught in their prop wash. Without having tripped the shutter even once my arms felt like cooked spaghetti.

After the helicopter flew away I put the kite back up to a good operating altitude. Eventually I even start to take pictures, but for some reason nothing worked right! I’d used this camera for KAP before, but for this set of tests I was using a new card I’d just prepared that same morning. Of course none of my defaults were set up, so the whole setup was hosed. I’d forgotten the cardinal rule of… well… really of all photography: Do an end-to-end test of your gear at home before you ever take it out in the field!

Camera settings were wrong, things were blurry, the wind was gusty, but I did manage to get a couple of frames I thought might turn out ok. In frustration I finally landed all my gear so I could catch my breath. Within minutes the wind shifted 180 degrees, flipped my kite up and over, and dumped sand on all my gear. I dismantled the kite and started shaking the sand off my rig and camera. By the time I had everything packed the wind had shifted another three or four times and was blowing stronger than ever. I was glad to have everything back in the bag and ready to go.

By the time we’d hiked back to the car the wind was howling. Well out of rokkaku territory and well into Nighthawk speeds. It was clearly time to go.

When I got home I was pleasantly surprised to see that despite the helicopter, the blurries, the blown panoramas, despite everything, one frame did turn out.

Anaehoomalu Bay Infrared Aerial

I spent the next morning sorting out all the native Canon and CHDK options so the camera would do what I wanted. Then I repeated all those settings on my unconverted A2200. Next time I’ll be better prepared. And next time I’ll test everything at home before I head out!

– Tom

P.S. Next step: Mounting both A2200 cameras on the same KAP rig for 4-color photos!

Posted in Kite Aerial Photography, Photography | Leave a Comment »

Yet More Experiments

Posted by Tom Benedict on 11/06/2014

Since I wrote New Experiments I’ve accomplished three out of four of my goals: My Gopro has a frame case and a remote video/power cable, so I can use it with the video downlink on my KAP rig and on my airplanes. I built a set of parts that let me move my KAP rig from various suspensions to a pole and back. And I built a helmet cam that aims remarkably well, though that’s still a work in progress. Of the set I wrote about in New Experiments only one is still on my plate: the OrangeRX Flight Stabilizer Hack. And it’s well underway at this point.

I honestly thought these would take more time! So rather than sit on my thumbs I came up with a new list:

Project 1 – OrangeRX Flight Stabilizer Hack

Yeah, still on the top of the list. I now have three stabilizers in hand, one of which has been flashed to the Open Flight Stabilizer firmware. Given the functionality of OFS I think it’ll be a drop-in stabilizer for a KAP rig. How well it’ll stabilize the rig still remains to be seen. And that leads me to:

Project 2 – Passively Damped Parallelogram Pendulum Suspension

This is a return to an earlier project I never finished working on. But the time served me well. I think I’ve simplified the design enough to make it straightforward to build. I also think I may have at least partially solved a long-standing problem with pendulums and Picavets alike: Taking out sway around the kite line. If this works then both fore/aft and side-to-side sway will be reduced and slowed down enough that an RC flight stabilizer might actually stand a chance of keeping the camera from rocking and rolling. Details to come.

Project 3- R,G,B,NIR Imagery from a KAP Rig

This is hardly news. I know a handful of people who are doing this or who have done it in the past. Scott Armitage, Chris Fastie, and I’m pretty sure Ned Horning have all done this. I’m just following in their footsteps. The two big fab items on this are a dual camera mount (done!) and a GentLED-CHDK Y-splitter cable so I can trigger two cameras at once (parts on order). The big purchase with this is a second Canon A2200 to replace… no… to augment the one I converted to NIR (already in hand!) This should come together relatively quickly.

Project 4 – KAP Gear Consolidation

In many ways my current KAP setup has brought me exactly where I’ve wanted to be for a long time: I can use a range of cameras on the same rig. I can get video feedback from all of them. Gear failures in the field are at an all time low. I can adapt my gear to whatever the circumstances require.

And my bag weighs like a brick! I’ve got more KAP goobers in my bag than I can count. Setting up a kite? No problem. Setting up my rig? It’s a maze of batteries, cables, antennas, oh my! I want to consolidate my gear to make it easier to carry and use.

The biggest changes on the rig will be moving the video transmitter, changing the antenna to a permanently installed cloverleaf with a radome, and neatening up all my cables to make life easier. But the biggest change will be to my transmitter: I want to rebuild the back of my video monitor so I can bolt a little hand unit to either side for either left or right handed operation. The hand unit will include a single joystick and button, as well as the RF board and antenna from my existing transmitter and either an Arduino Mini or Baby Orangutan board as the brains. If I build it the way I’ve envisioned, it should be about as wide as the joystick and about as long as the monitor. I think I can get the depth to match the monitor as well. Once it’s installed on the monitor the monitor and transmitter should make a nice neat ready-to-use package that should cut down on the amount of gear I have to carry by a good bit.

This is by far the most invasive project, and will be the last one I take on. But if the damped pendulum and the rig stabilizer work out, it’ll be a welcome change.

– Tom

Posted in Engineering, Kite Aerial Photography | Leave a Comment »

World Wide KAP Week 2014 Recap

Posted by Tom Benedict on 02/06/2014

I mentioned it a couple of times in earlier posts, but World Wide KAP Week 2014 just finished. Unlike a lot of annual “week” type events, World Wide KAP Week has no fixed time frame. Since good flying weather may start at different times of the year depending on where you are in the world, each year the dates are a little different so that no one spot on the planet gets the best conditions for WWKW. Some years it’ll favor those at more northern latitudes, other years it’ll favor those more in the south. This year it ran from Friday the 23rd of May until Sunday the 1st of June.

My WWKW started off great. One of my kids had an end of school year event at Anaehoomalu Bay, so I grabbed my KAP gear and brought it with me. I flew my Canon A2200, a camera I’d originally intended to convert to infrared. I probably mentioned it before, but I’ve had mixed results with the A2200 in the air. This time I think I finally got the issues sorted out. I came away with some good single frames and one really nice panorama.

WWKW2014 Anaehoomalu Bay Panorama

The next day I grabbed my gear and headed down to the anchialine ponds near the old village of Wainanalii. I wrote about this in another post. Just prior to WWKW I’d finished work on an aimable helmet cam. I tried using it to document my KAP session at the anchialine ponds with mixed results. Rather than fly the A2200 this time I had it mounted to the helmet running an intervalometer. But instead of coming back with a card full of stills the way I thought, I came back with a card full of three second movies made every five seconds. I’d left the camera in video mode! Regardless, the Gopro frames worked out well enough that I was able to de-fisheye some choice ones and put together a small set of photos for my blog post. The ponds were beautiful.

Golden Pools 1

I was weathered out Sunday and Monday (Monday was a holiday) so I didn’t get to fly until later in the week. In previous years I’ve taken time off from work for WWKW, but with everything else going on in my life I just couldn’t do it this time. In a way, though, I think that worked out ok anyway. I’ve been trying to do more KAP toward evening when the light is better, so this just forced my hand. Tuesday evening after work I drove down to the coast with my KAP gear and photographed Puu Kohola from the nearby harbor. KAP on that part of the island is always iffy, but for some reason everything came together this time. It was the perfect mix of good light, soft wind, and the best slack-line flying I’ve had in years.

Puu Kohola Panorama

The weather closed back in Wednesday, so I only got one other session in for WWKW 2014. Saturday and Sunday two of my kids were at a swim meet here in town. I asked permission of the organizers to do KAP over the event and was given the go-ahead. The wind was far from ideal and at one point the shear layer coming off some nearby trees caused a really nasty vortex that caused my kite to overfly and turn toward the ground. Rather than risk the safety of anyone at the event I walked everything downwind and finished up the session there. All of my KAP was done during a break in the competition, so when the whistle blew for the meet to get back underway I packed my gear down and went back to being a swim dad.

HPA Pool 1

Sunday afternoon after the meet finished I threw all my gear in the car along with my helmet cam, my Zagi 5C, my transmitter, and three coolers. It was time for the bi-weekly trip to Kona to go grocery shopping at Costco. But there are a couple of good spots to do KAP and slope soaring along the way, sooo…

By the time I got to the cinder cone at Kua Bay the wind was rocking. It was really too much for KAP, and as I learned a few years ago Kua Bay is inside the five mile radius of Kona International Airport. I looked at my KAP gear, looked at the plane, and… I parked by the cinder cone and grabbed my plane.

It felt a little weird flying a plane the last day of World Wide KAP Week. But in a way I’d already had the magic KAP session for the week photographing Puu Kohola. I didn’t want to end the week fighting a kite in that much wind. So I hiked up the cinder cone and had one of the best slope soaring sessions I’ve ever had. One flight lasted just over forty minutes. If I hadn’t brought it down so I could put on my helmet cam, I probably could’ve stayed up longer.

I even met a new friend while I was there. He was sloping a Radian – very different from my Zagi. So rather than getting helmet cam footage of me flying my plane, I videoed him flying his instead. When my cameras filled up I took off the helmet cam, picked up my plane, and kept going. (I did eventually make it to Costco.)

World Wide KAP Week 2014 was a fantastic kick in the seat of the pants. The past several years I haven’t been out doing KAP nearly as much as I used to. I probably did more KAP in those four sessions than I have all year. I came away with a broken kite (repaired Saturday), a broken video cable (repaired Sunday), a new pole head for doing pole aerial photography (built Saturday), and enough of a sunburn to remind me that hats only keep the sun off your face if you’re not looking up. Oh! And I came away with a lot of photos, some new spots to fly, and a smile I just can’t wipe off my face. I had a fantastic time. I can’t wait for World Wide KAP Week 2015!

Sunburn or no sunburn… Keep looking up!

WWKW2014 First Flight

– Tom

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KAP Rig to Pole Adapter

Posted by Tom Benedict on 01/06/2014

In my previous post I described some bits I’d made so that I could swap a rig from one suspension to another. I did this as the first step in getting into pendulum design. I needed a way to move my rig from a Picavet to a pendulum to whatever design I wind up testing so I can compare the performance of each. But even as I was making them I knew I wanted a mating part that would let me flip my KAP rig upside-down and mount it on a pole. Yesterday I got the chance to make the new pole head:

Pole Head

With a KAP rig most of the forces are axial: pulling up or down. With a pole rig the forces are mostly axial, but if for any reason the pole leans to one side the forces become radial: pushing out sideways, wanting to bend things. I knew the joints on the KAP adapters I made were plenty strong, but I wanted something a little beefier for the pole.

The core of it is one of the KAP adapter bits I’d made previously. The outer shell is the new part. It started life as a length of 1″ diameter 6061 aluminum. I bored out the bottom to match the depth and inside diameter of the original pole head. Once that was done I flipped it around. I turned the remaining outside diameter down to 0.6″ and put a 45 degree taper to transition between the narrow and wider parts. There’s a good bit of metal between the bottom and the taper at the top, so it’s plenty strong. Once the outside was done I drilled the inside 0.375″ to match the KAP adapter bits and drilled a #8 clearance hole between the upper and lower halves of the thing. The only step left was to cross-drill the lower half with a 0.128″ hole for the rivets. The original pole head had nice flats for the rivet heads, so I spotted each hole with an 0.250″ end mill to make a flat.

The 0.375″ hole on top is a close fit for the KAP adapter, but not so close that I had to force the part into place. I put some blue Loctite on the screw I used to secure it to the pole head, so it shouldn’t go anywhere. Once the head was pop riveted to the pole, the work was basically done. But I abuse my pole, and I knew the head would take damage if I didn’t do something to protect it. So I chucked up a piece of PVC pipe, faced off both ends, and used it as a cap. With the lock screw backed out just right, the cap is a snug fit and won’t fall off in transit.

I really wasn’t planning on pursuing this during World Wide KAP Week. Not with so many great places to fly. But weather is weather. Sometimes it cooperates, sometimes it doesn’t. The winds in town were gusting so I ducked into the shop to make this while I waited for conditions to improve. This morning the sun rose to a clear sky and almost zero wind. Here’s hoping there’s something to fly in this afternoon!

– Tom

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Interchangeable KAP Bits

Posted by Tom Benedict on 29/05/2014

Now that the aimable helmet camera is finished I’m on to the next project: interchangeable KAP bits.

A kite aerial photography rig is made up of two main parts: a suspension and a camera mount. The suspension is the bit that connects the KAP rig to the kite line. The camera mount is the bit that holds the camera and lets the photographer aim it at the subject. Each of these can be as simple or as complicated as the rig builder wants them to be. In previous posts I’ve talked about a number of ways to over-complicate a camera mount. In the near future I hope to come up with some new ways to over-complicate the suspension. But in order to do the testing I want to do on the new suspension I need a way to swap one rig between a Picavet, a pendulum, a handheld pole, or what have you. This is what I came up with:

KAP Suspension Connector

I made these out of 3/8″ 6061 aluminum round. Square stock would’ve worked just as well and wouldn’t have required a lathe. The two bits are threaded to go onto a Brooxes Better Gear Guide pan axle and to take a Brooxes Picavet. Both of these use #8-32 screws. I used the same screw thread for the two screws that hold the two parts together. There’s nothing magic about the #8-32 screw. If your rig uses metric hardware you can use metric hardware for this part as well. M4 is a good size.

This probably would’ve worked with one screw, but I like backup when it comes to KAP rigs. Having a camera fall out of the air is never a good thing. Besides, by using them in opposition like this I was able to design the parts to be identical regardless of whether you’re talking about the camera end or the suspension end. The two halves are entirely interchangeable. In both cases the outboard hole is tapped #8-32, and the inboard hole is drilled for tight clearance on a #8-32 screw.

Between the two screws is another hole. I originally designed the hole to take a 1/8″ dowel pin, so these are drilled a few thou under the 0.1240″ diameter of my press-fit reamer. The idea was to ream one as a press fit and the other as a slip fit. But in the end I decided the dowel pin wasn’t really necessary, and having pins in some of the parts and not in others would’ve broken the nice symmetry I’d built into them. Which leaves the question: what to do with that hole? Easy! Safety tethers! Now there’s even more safety in case both screws fall out.

I’ll have the opportunity to try these out during World Wide KAP Week 2014. Meanwhile I’m building a slightly beefier version of this to use on the end of a 25′ painter’s pole. Once that’s done I’ll be able to use the same KAP rig on a Picavet, a pendulum, or a pole, just by popping out two screws.

– Tom

P.S. I typically write a post over the course of several days, editing at the beginning of a writing session and writing during the second half. In the middle of this post’s write/edit cycle I was approached at work about the possibility of doing some still photos using a cable cam. Only problem: we don’t have a cable cam at work. Hey, no problem! The suspension on my KAP rig is now interchangeable! So swapping it over to whatever cable cam system we build is a no-brainer. YAY!

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