Intro: Traditional Polynesian Ice Canoe (Ice Proa) - How to Kite Ice Sail
Once it's too cold to kitesurf in the water, it's time to find a frozen lake and kite on top of the water. Build a "traditional" Polynesian ice canoe using aluminum extrusion or whatever material you have at hand. If the water ever froze in Polynesia, I'm sure this is what their ice kite/sail craft would look like.
Step 1: Ice Kite Buggy Didn't Work So Well
Step 2: A Brief Introduction to Kites
All kites fly and generate force within some quarter sphere defined by the kite itself, the pilot, and the conditions. The homemade 9 m2 nasawing, shown here flying above Quaboag pond, flies in an angle a bit greater than 135 degrees; some very efficient foils can push that angle much further.
Step 3: It's All About the Edge
To get going on the ice buggy, you edge against the pull of the kite and use only the component of force that points in the direction you want to go. Rarely do you want to be pointed directly at the kite, so the pull of the kite is almost always to the side. Since your feet are used to steer, there isn't much to hold you in the buggy. (Some more advanced buggies have specially designed seat to counteract this problem.)
Step 4: Turn to Leeward!
After a full day of ice kiting left me with a sore back and bruised hips (especially after a couple of crashes where I was actually pulled completely out of the ice buggy), it seemed clear I needed a proa type vehicle - something which has a constant windward and leeward side. I wanted to sit with the wind to my back and use my feet to steer and to hold my position in the vehicle.
Step 5: Use Scrap Material and Expensive Machine Downtime
With a bit of CAD, some leftover 8020 structural aluminum, a few jet machined connectors and blades ...
(download the zip file full of all the CAD drawings)
I designed it to use abrasive jet machined aluminum connectors and extruded aluminum bars. The blades were also jet machined from stainless steel and sharpened to a 90 degree angle by hand. The flexure is polycarbonate. You could accomplish the same thing with scrap steel from a bed frame welded together.
Step 6: It's Fast
Behold! The Ice Proa!
The plastic beam on the leeward side is a flexture that turns the two skates. Push out in the center at the footstrap to go upwind, pull in to go downwind. The flexture is rigidly attached on one side and slides on the other.
Step 7: Action!
Step 8: More Details
Step 9: Improve
After bending the rear blade, I made a much wider rear blade from 1/4 inch stainless steel. I also put a foot rest on the outside of the steering connectors.
Step 10: If You Do Nothing Else, Watch This One
Step 11: Safety Equipment
You'll want all manner of safety equipment to play on frozen lakes. The best thing to do is to find some ice fisherman and ask them about the thickness of the ice and if there are any thin areas. In New England there's an ice report website from NEIYA.
Check out the image notes for specific safety gear. More information here.
Step 12: Freeze
Enjoy freezing temperatures like never before.