Instructables
Picture of DIY Picavet Cross for Balloon Photography
I built a simple picavet cross to hold and stabilize my camera when I sent it aloft using helium balloons.

A picavet is a self-leveling rig that attaches to a kite or balloon string. The picavet stays level even while the string changes angles when blown by the wind.
 
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Step 1: Making use of "trash" as building material

Picture of Making use of
I wanted to put my Canon SD1100 IS up in the air. I wanted to shoot video not stills and this camera does great video.

The picavet rig will hold the camera level and facing down no matter what angle the balloon string is. The picavet is like a self-leveling marionette platform.

My camera fit into the foam packaging from my G1 phone perfectly.

Step 2: Parts and stringing it all together

Picture of Parts and stringing it all together
I used the instructions on this page to figure out how to build and string my picavet http://www.kaper.us/basics/BASICS_picavet.html

I
 taped the packaging up at the corners and used scrap wood and eyes in the corners of the cross.

I didn't trust myself and restrung the kite string a couple of times until I convinced myself it was right. The key is that until there's weight in the picavet, the self-leveling doesn't really work. Empty picavets aren't as good as full ones.

Step 3: Now go launch your ballloon!

Picture of Now go launch your ballloon!
I used very small carabiner-like clips to attach the picavet to the kite string.

Watch this video of our camera launch to see how it all worked together: www.youtube.com/watch?v=O7RyHSwMvqs

I store my picavet attached to a coat hanger so the string doesn't get tangled up and it's ready to use the next time. (and there will be a next time!)

More details: www.JetCityOrange.com/balloon-photography/
bwrussell3 years ago
How do you think this set-up would handle severe winds and sudden updrafts, possibly with the entire balloon rig flipping end-over-end? It wouldn't need to stay level during this obviously, just not get completely tangled.
JetCityOrange (author)  bwrussell3 years ago
I've been thinking about revisiting this project once the weather gets better. One lesson I learned is never underestimate the power of the wind! We're on a hill at the end of a peninsula overlooking Puget Sound and there's wind coming from all directions all the time.

My Flip video camera is lighter and while this means less ballast it also means it will take fewer balloons to get it aloft. The other thing we all agreed was almost a necessity was a way to reel the string in and out faster. As Cub Scouts we used to take a piece of wood (let's say 8"x10") and cut a broom handle to use as handles.

Bad drawing but the broom handles extended to one side at the top and the other side at the bottom so we could pull in 10" X 2 every rotation.

I hereby promise to post an update once the weather warms up!
kite.bmp
My possible application is with a high altitude weather balloon, so untethered. Some people have had their entire rigs flipped ballast over balloon, which is fine with a static tether but never having used a picavet I was wondering if that sort of motion could cause problems.
jooknon3 years ago
Do you have any of the video your camera took? I was hoping you would show what it could do on your site.
Otherwise, very cool build
JetCityOrange (author)  jooknon3 years ago
Try looking here: http://www.jetcityorange.com/balloon-photography/video/

Too bad I didn't notice that the lens was zoomed all the way in. The video doesn't do justice to high it went. Next time...

thanks,


Jerry
Cederic3 years ago
Looks good... but according to the instructions you linked to, the eyes should be perpendicular to the direction of the strings, not along them. (I.e. you need to turn each eye 90 degrees.) This should allow the box to self-adjust even with a lower weight in it, and give a better result.
JetCityOrange (author)  Cederic3 years ago
I'll give it a try. Thanks!
JetCityOrange (author)  Cederic3 years ago
If you look, the eyes are oriented the right way. The cross is 12-3-6-9 o'clock in this photo.
picavet-cross.jpg
After going through the instructable again I realize I might have been mistaken. I believe I was thrown off by the video, in which you show the picavet on its storage hanger - When applying the picavet to a mount with two different mounting points (which is the best for self-levelling action) the mounting points should be at 10 and 4 (or 9 and 3, wherever it settles) in your photo, not 12 and 6 as you have it in the video when stored.

JetCityOrange (author) 3 years ago
I just put my picavet on the scale at the food co-op just now. .34 lbs for the picavet itself and .66 lbs total for the picavet with the camera.
gomiboy3 years ago
Do you suppose this type of rig would work for one of those weather-balloon space shots? One of the problems with those is the severe bouncing of the image. If you have no idea what I'm talking about, you can look at http://space.1337arts.com for an example.

Nicely done!
JetCityOrange (author)  gomiboy3 years ago
I was really satisfied with how the picavet performed. My biggest mistake was not checking the camera (or I would have realized it was zoomed all the way in).

The things I do differently? More balloons to get more lift vs drift. Timing it for little or no wind. Having a reel or some way to handle the line quickly without it getting tangled up.

The picavet? A real winner!

I'll try to throw it on the digital scale at the food co-op and get the weight of the rig and of the rig with the camera.
swilus3 years ago
Very cool! I sent a flip video camera into the sky. It took approx. 40 12" balloons. Let us know how many balloons it takes you!