Kite Tests on Land and Water

Jan 29 – Arrival in Bermuda

1/29/12

Don and Joe arrived in Bermuda and met the Lone Ranger research team. Don kitesurfed around the boat and he and Joe took some photos at the dock.

Testing new rokkaku kites

1/17/12

Dudu and Betsy tried out a couple of new rokkaku kites this morning, and he, Don, and Betsy went out this evening to try some more. The photos preceding each label depict that model in flight.

From Dudu:
Our prototypes from versions 26 27,28,29 and 30 are made with the 2 piece light Dacron material with the closing seam on top of the tubes. This caused the curve to be flatter than usual.

We tried to fix this issue on version 30 by adding more curve to the design, but we also changed the curvature flow, getting more curve at the center than the tips. This resulted in the same maximum, but the new flow is not ideal, making […more]

Balloon kite flight

1/13/12

Yesterday Dudu inflated both of the new balloon kites in the shop and left them overnight to insure that there were no leaks. Today we inflated one with helium and launched it outside.

Balloon KITE DATA:

Diameter of Burger: 2000m
Height to Diameter ratio: 0.6
Height of Burger: 1200mm
Volume of an ellipsoid: 4/3 * PI * a*b*c
(a,b,c are each radii, so a=b and c=height)
Volume of our Burger: 4/3 * PI * 1*1*0.6 = 2.5 cubic meters
1 cubic meter = 35 cubic feet
Volume of Burger: 88 cubic feet

We used the 110cubic feet tank of helium to fill and there was some left.

Our 3D gas kite improved the […more]

China trip December 2011 – ROK kites

12/19/11

On this trip we made many ROK kites with the latest updates. We took the prototypes to fly at our usual test site and based on the results, designed some more with the new ideas and new software results.

On the materials side, we made 3 ROKs (3 different sizes) using Cubic Tech CT3.5, with Tapeglue along the intersegment panels and dacron reinforced stitch closing seam. The result was good, but after keeping the kites inflated for 3 days, the bottom of the main intersection started to fail, proving that we can’t use tape at that spot. We are fixing that by making the intersection with dacron, after a transition from the CT3.5

The other tests were 2 new sizes:
[…more]

Kitefoiler Test – Sep 16

9/16/11

We took the Kitefoiler out at dusk today to test Pete Lynn’s newest kite, the 25 sqm flat kite that we used on Sept 6, with Pete. We went out with the kite under-inflated in order to try and mimic the deformation we saw on the 6th, when the wind was much higher. The kite did indeed deform today, although less drastically than last week. The kite was folding into a C-shape instead of maintaining its flat silhouette. One solution to this problem would be to add more bridle lines, as on Armand’s flat kite, but that’s a solution we’d like to avoid if possible. Pete is pondering other options, including fatter struts.

Beach test of kiteboat kites – Sep 1

9/1/11

Today, Don, Dudu, and Pete Lynn went to Crown Beach to test Pete’s new 25 sqm flat kite with the bridge bridle. We also compared it to the MB6-25-v10-9s kite, which is so C-shaped that it is almost U-shaped (last three photos).

We spent most of the test adjusting the brake lines on the flat kite and talking about the turning of that kite and also talking about the spread of the back lines–how wide they get by the time they attach to the kite.