Looking for RC Inspiration

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This is the most successful version of my kite aerial photography rig.  It took 3 prototypes and 3 or 4 refinements to get to this design.   The first one was too flimsy, the next one was too heavy, until I finally had enough lift and a light enough load.  It’s been 3 years since I looked at this design, so I think I’m going to scrap it and start over.  I can still use what I’ve learned about the process.  Here are some things to keep in mind if you’re trying to start into aerial photography.

Buy rechargeable AA batteries and standardize on them.  The Nikon 885 uses a special battery, $13 a piece.

I’m going to try a plastic frame next time.  My first metal frame was WAY too heavy.  Think about weight from the beginning.

I’ve settled on an 8 foot Delta Conyne to lift the rig.  The first kite I tried didn’t have nearly enough lift to get the rig into the air.

Think bigger about the kite, and smaller about the rig.

I’m not sure that the frame within a frame design is the best one to go with.

I think it would be a good idea to control the orientation of the camera from the ground.  With this rig, I have to bring it down to the ground to change the yaw or pitch of the camera.   I could achieve Pitch just by adding a servo to the outside frame and changing the middle nuts/bolts into ball bearing joints.  Yaw is a little more complicated.  The yellow wheel on my rig was me thinking about controlling yaw from the ground.  It’s geared, but I couldn’t find a satisfactory way to turn it with a servo.  Most of the connections I thought of put too much weight on the small shaft of the servo.  I think a rod and gear design is the best way to connect the frame to the Picavet.  Close to what I did above, but with the gear connected to the bolt, and a rotating joint at the head of the bolt.  I’m going to have to be very precise when I drill the holes for the bolt and the servo.  If they don’t rotate around each other in a perfect circle, the gears will wear, or the rotation will stop.

I’ve been toying with the idea of replacing the kite with RC helicopter blades.  That would require a stabilization system and more sophisticated power controls than I have.  As I was researching the idea, I ran across the Dragonfly company.  My idea was for three booms and single engines, but I think their design of double engines on quad booms is much better.  The complexity of powered aerial photography quickly got out of hand.  here are some youtube videos of people trying to lift things with RC helicopters.

So, I’m back to the Kite and camera.  Cameras have gotten a lot smaller and lighter in the last couple years, so I think it’s a good time to try some KAP.

Heights

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As I heard Mike Rowe say recently, “It’s not heights I’m scared of, it’s widths.”  I don’t think I’m overly afraid of heights.  Whenever I stand at a precipice, I can feel part of myself panic.  It takes some will to suppress that panic, and the higher I am, the more will it takes.  What makes sitting in an airplane seem perfectly normal, and standing on a ledge seem so dangerous?  There must be some psychology at work on a plane, making the environment seem less like 35,000 feet, and more like a living room or bus.  Skydivers must imbue that feeling of safety in their parachutes.  How else could they even stand at the door of a plane?   I guess that people who aren’t afraid of heights rely on their balance or insanity to get them through.  I think everyone’s looked over a safe ledge or platform to test themselves.  It’s a little thrilling to look down from a height and still feel safe.

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I went on an Outward Bound trip when I was in sixth grade.  We did a lot of things that this suburban kid had never done before.  We walked through a waist deep pond, navigated with a compass… and rappelled off of a 100 foot tower.  I think that’s the first time I had to deal with heights.  Dan Shechtman was at the top holding the safety line as I started up the ladder.  At first, it wasn’t too bad, it felt like climbing any ladder.  After about 20 feet, I started to feel that panic fighting against me like gravity.  I felt a little heavier after each rung.  Dan could see that I was scared, and kept encouraging me.  When I reached the top, there was a final hurdle that I couldn’t overcome.  Dan had put the safety line over the safety barrier, but I couldn’t climb over it.  All I could manage at that point was to flop under the railing and lie on the platform panting.

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I never really felt relief at getting to the top.  There were only two ways down, after all.  I wasn’t going near that ladder again, so that left rappelling off the front.  The front of the tower was covered with planks until about 20 feet off the ground.  I crawled towards the edge, then turned around and hung my legs over the edge.  It took a bit of coaxing before I really trusted the line to support my weight, but a second later I was hiked out on the wall, 100 feet up.  I froze for a second, but I had a good wide stance, and the panic became more manageable.  I let my death grip on the line go a bit and stepped down the wall.  The carabiner pinched my finger just as Dan said “Watch your right hand!”  It hurts, watch your right hand if you ever go rappelling.  That kind of woke me up a bit, because the line felt really real twisting my finger like that.  I stood up a little and freed my hand, and jumped out a bit.  the line slid through my hands until I squeezed and swung back to the wall.  Rappelling is a lot of fun, and I bounced my way down the wall until I met the last 20 feet.  By then, it wasn’t a big deal, and I hovered down to the ground with some grace that had been missing up till then.  I think it’s good for me to look over a tall height from time to time, just to remind myself what it takes to overcome a fear.

New Kite New Bracket

I’m sorry I haven’t been online this week. something personal came up and I’ve been focused on that. I did get out for an hour today, and I decided to try out my new KAP rig, version 3, maybe 4, if you count the mickey mouse rig I tried first.

Yeah, I know, another school. A soccer field this time… football pitch, if you must. that’s the New York State Thruway and a golf driving range in the background. It’s boring, but I’m still testing the kite and the camera rig. I think I need a new camera. These pictures have a lot of pixelation. We’ll see.

Here’s the new rig. I moved the servo up to the top of the frame and added a twisted wire to trip the shutter. I make fishing lures out of stainless steel wire, so I had the tool to wrap the wire. When I tried it with a single wire, it wasn’t stiff enough to take a picture.  The twisted wire is more reliable than the direct connection I used before.  It missed fewer shots, but I still expected more than 79 pictures on the card when I got it home.  Maybe I went beyond the range of the transmitter for a while?

The new kite works pretty well. It bucks a bit in the wind, but I think adding a couple tails will stabilize it.

KAP Set, Rocky Mountain DC Kite

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Sperry High School

 I restrung the picavet for my camera rig.  It crashed twice, and the second time the picavet was toast.  I did get a few shots of the High School.

 Here’s a view over the high school.  that’s the Henrietta Dome Arena in the background.

KAP Set

KAPitulate? Never!

 When I tried camera bracket v1, the kite was only able to lift the bracket about 10 meters into the air… once.  I decided to build a lighter bracket.  I made camera bracket v2 out of 1/16 inch thick aluminum.  The other bracket was 1/8 inch thick.  The v2 bracket is at least 1/3 lighter than its predecessor.  I don’t have a scale, so I’m estimating.  Once I got bracket v2 out in the field, I had the same problem.  IT’S TOO HEAVY!  I’ve already put the bracket on a diet, time to bulk up the kite.  I’ve had this old French Military Kite for years.  The cat chewed through the bridle a while ago.  After restringing the bridle, I took it out to the field.

 

 Ta da!  Left is the neighborhood next to the local high school.  Right is the roof of the high school.  I took about 100 pictures.  most of them were blurry.  I have to change the camera settings to get a faster shutter speed.  My French Military Kite also has a tendency to veer to the left since a crash some years ago.  The camera was swinging quite a bit at times.  The kite’s cross spar broke towards the end of the flight.  That’s ok, it was 20 years old, it doesn’t owe me a thing.  For now, I have a working aerial photographic rig.  It’s cobbled together and needs maintenance after every flight, but it works. 🙂

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Maiden Flight

 I looked out the window this afternoon and saw the bending branches.  Inspired, I grabbed the dog and headed for the High school playing fields.  I was only there for 15 minutes because my rig is TOO HEAVY.   The kite was only able to lift it a couple times.  These pictures were taken from the highest altitude I achieved. I think I have to adjust my trigger servo.  I triggered the shutter a dozen times, but only got 2 pictures on the card.  For a first try, it’s not bad.  I didn’t break anything…

Back to the drawing board.  I either need a bigger kite or a lighter rig.  I’m going to try a lighter rig first.  I thought aluminum would be light enough, but when I got the whole thing together, it was heavier than I anticipated.  Plexiglass might work.  I have some from a car computer that never got built.  I learned how to bend plexiglass with a propane torch on that project.

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Camera Bracket

I still have a couple things to do to the bracket before it’s ready to fly, but I’m getting close. I still need a cap nut at the picavet. It’s all held together with a zip tie right now. I also need to trim the threads of the eye rings on the picavet.

Kap photo set

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