foils

Kitefoiler kite & radio test – Apr 5

4/6/11

Yesterday we took the Kitefoiler out to test it with a kite and three T-foils again. Additionally, we tested the newest hands-free radio prototype from Paul Larkin, who visited from InduComm to show us the system. The system fits inside one ear of a crew member and picks up voice through his or her jawbone, a setup which is meant to reduce wind noise. We taped the radios themselves to the outside of each person’s drysuit. There are one captain’s headset and several crew headsets. The radio has both push-to-talk and open-mic options. For our test, Paul wore the captain’s headset on the Protector, and Don, Joe, and Richard wore the crew headsets on the Kitefoiler. Paul attached a directional […more]

Kitefoiler Tow Test – Mar 30

3/30/11

We tried the side T-foils on the Kitefoiler for the first time today. They performed very well in the glassy conditions, demonstrating much more lift than the J-foils, and foiling stably with little spray on the crew. The boat also had no trouble foiling with five people on deck. Don’s parents, Sharon and Roland, and Erika came out to help round out the crew.

Kitefoiler tow test – Mar 29

3/29/11

We went out for a brief tow test today to check adjustments to side foils and to compare performance of original T-foil rudder to newly fabricated larger T-foil rudder.

The attached plot compares the speeds and loads with each rudder T-foil. The speeds are not identical in each case, and other factors such as the tow angle and acceleration may have varied between runs. However, there is some indication that the “new” foil requires a larger towing force at 20-21 knots.

Kitefoiler kite test – Mar 28

3/28/11

We tested the Kitefoiler today with the new rudder. Using the kite-launching mast, Don, Joe, and Richard successfully launched and transitioned to sailing for the first time and on the first try!
Thereafter, they sailed the boat to test the foils. Both Joe and Richard sailed with Don, but the wind was such that foiling was only possible with two crew members at a time. The foils worked but adjusted unevenly, causing the boat to jump a bit as it sailed. The foils tested were one original J-foil (starboard), and one new, modified from old quadfoiler, more steeply angled J-foil (port). We will test again shortly after further foil adjustment.

Kitefoiler Tow Test – Feb 10

2/10/11

We towed the Kitefoiler again today. We added a pulley system that allows us to adjust the J-foils from the steering position at the stern of the boat. These pulleys worked very well. The port foil was sticking and not moving correctly as it did yesterday, but due to the glassy bay conditions, this did not prove a problem for our very short test. Henry visited the shop today and rode on the boat with Don and Joe.

Three Kitefoiler tow points were tested, each with the powerboat pulling at at 45 to 60 degree angle. The graph shows the measured forces and speeds for each tow point. The 3rd point appears to have reduced the load over the 1st. […more]

First Kitefoiler Kite Test – Feb 4

2/4/11

We performed the first Kitefoiler test with a kite today. Greg Ketterman, designer of the Trifoiler, joined us on the test. Prior to testing with the kite, we towed the boat to the city and back around Treasure Island to make sure that everything was working as expected. The foils were a little looser than we would have liked, but the wind picked up, so we tried the kite anyway. Despite the mediocre wind speed, the boat performed very well, foiling consistently with two crew members in the area between Angel Island and Chrissy Field. After returning to the shop, Joe disassembled the cassettes and found the problem with the foils–the stress on the bearings had caused them to fall […more]