09_2015_kaiconcepts_sep_monthly

Kai CONCEPTS
UPDATE SEPTEMBER 2015
Kai Concepts
Monthly Update: SEPTEMBER 2015
KITEBOAT PROJECTS
K2 Development & Testing
Downwind Performance....................................................................................................3
Custom GoPro Mounts.....................................................................................................5
T-Foil Electronics Covers.................................................................................................5
K4 Development
Ama Bulkheads & Flanges................................................................................................6
Kite Deck.......................................................................................................................6
Kitearm Bulkhead............................................................................................................8
CONTRIBUTORS: Joe Brock, François Gounard, Adam Hill, Don Montague, Betsy Pfeiffer,
Alex Pouchkarev, Jamie Schulte, Paul Stanek
(on front cover): K4 kite deck with chair track
KITEBOAT PROJECTS
1 K2 Development & Testing
SUMMARY
This month, we entered the kiteboat in the Ronstan Bridge-to-Bridge race and we conducted a long downwind test
in preparation for the race. We made several small upgrades to the boat, including fabricating custom GoPro mounts
and finishing the carbon covers for the electronics.
PROJECT DETAIL
1.1 Downwind Performance
At the beginning of this month, we conducted our first real test of the boat’s downwind performance
with the new T-foils. As discussed in last month’s report, the T-foils appear to have improved the kiteboat’s upwind
performance, which was unexpected. We did anticipate, however, that the T-foils would improve the boat's downwind
angles, which would be ideal for our eventual Transpac goal with the larger boat.
K2 Test: September 2nd
On September 2nd, we towed out past the Golden Gate Bridge and sailed the Bridge-to-Bridge race course, from
the Golden Gate Bridge to the Bay Bridge, with the KB-KW-40D, the 40 m2 high aspect ratio Ken Winner kite.
We finished the test by successfully sailing under the Bay Bridge on the west side of Yerba Buena, the official race
finish line and a difficult location to keep the kite in the air.
The boat’s performance on the downwind course was really impressive. Handling the boat and large kite in
the chop and wind outside the Golden Gate was challenging, but once we were inside the bay, we were able to
execute foiling jibe after foiling jibe en route to the other bridge. Boat data confirms that kite line load was very
low during loop jibes. In the three jibes highlighted below, the speed never dropped below 15 knots, and the boat
was effectively going dead downwind faster than the wind. A rough estimate based on this day’s data suggests
that the boat’s best downwind performance could have improved by as much as twenty degrees.
(above) KAIView data from September 2nd, showing a series of foiling loop jibes, throughout which the kiteboat maintained speeds over 15
knots with very little kite line load—graph shows boat speed in kts in red, wind angle in deg in purple, and total kite line load in kgf in black
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(top left): GPS track from September 2nd,
highlighting foiling jibes shown in graph
on previous page; (top right): rough water
outside the Golden Gate Bridge; (bottom
right): preparing to launch the kite outside
the Golden Gate
Ronstan Bridge-to-Bridge Race: September 3rd
On September 3rd, we repeated the Bridge-to-Bridge course in the actual Ronstan event. A delayed start and low wind
near the finish made the race difficult for many entrants to complete. K2 placed a respectable fifteenth overall and
first in the Open class.
(left): K2—red kite
center of photo—
prepares for race start
amongst other entrants
on September 3rd
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1.2 Custom GoPro Mounts
During a break from testing this month, we made eight new permanent camera mounts for K2. The mounts combine standard GoPro mounts with custom-machined Delrin parts and custom-fabricated carbon supports and splash
shields. These fixed mounts will protect the cameras from line snags and excessive spray and will make mounting the
cameras simpler. They also allow us to mount cameras in places we could not previously.
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(top left): faired cover for mast camera protects it from tangling on kite lines; (top center): beam-mounted camera; (top right and bottom left):
these custom mounts allow us to place cameras in places we could not previously, like on the bow and stern of the amas; (bottom right): this
carbon support replaces a plastic clamp which would bend when hit by wave or bumped by a crew member
1.3 T-Foil Electronics Covers
Other upgrades to the boat this month included finishing and installing protective carbon covers for the T-foil
electronics.
(above, from left to right): first iteration of electronics cover; modification to cover; final version of T-foil electronics cover
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2 K4 Development
SUMMARY
We have been steadily working on K4 over the last several months. This month, thanks to a lull in testing, we were
able to focus more of our energy on the build. We also hired a new part-time carbon specialist, Elizabeth Goodine, to
help with the work.
PROJECT DETAIL
1.1 Ama Bulkheads & Flanges
The K4 ama bulkheads and flanges are complete. Once we finalize the design for the foils, we will be able to make the
foil boxes and join the two halves of each ama.
(top left): François and Adam—intern—fabricate pre-preg bulkheads
for K4 amas; (top center): detail of
ama flanges; (top right): detail of ama
bulkheads and flanges; (left): two
halves of one bulkhead, ready for foil
box
1.2 Kite Deck
We finished fabricating the center hull pieces that fit under
the kite deck, and this month we have been sanding and
fitting them to the hull and the kite deck. We fabricated the
kite deck in April, and this month we made and installed
the kitearm bearing in the center of the deck, and installed
the track on which the kite chair will slide.
(right): underdeck pieces fitted to hull
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(top row, from left to right): kitearm bearing part; Paul installs kitearm bearing; (middle
row, from left to right): underside of kite deck, showing kite rail attachment bolts; same
view, showing entire deck; (bottom row, from left to right): top of kite deck with kite chair
track—custom made by Harken—installed; close-up of cars on track
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1.3 Kitearm Bulkhead
We designed and machined a mold for the large center hull bulkhead that will fit under the K4 kite deck, and we laid
the dry fiber for the majority of the part. Early next month, we will infuse the part and fit it to the hull.
(top left): kitearm bulkhead mold in CAD; machining the same part on fiveaxis router; (bottom left): K4 center hull with plywood placeholder in shape
of kitearm bulkhead; (middle right): laminate schedule for bulkhead; (bottom
right): Elizabeth lays dry carbon in bulkhead mold
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