Search found 503 matches

by Bill Roberts
August 4th, 2017, 6:58 pm
Forum: General Discussion
Topic: Pre-Bend
Replies: 9
Views: 4696

Re: Pre-Bend

Frank and Kevin To put the prebend back into a mast after it has been removed, wires removed, for some strange reason. Support the mast at the ends and sail track up. Hanging weights at the center of the mast is not needed or required. Pull a tight string from one end of the mast to the other. Measu...
by Bill Roberts
July 31st, 2017, 9:51 am
Forum: Technical Forum
Topic: Controlling twist on Square Top sail
Replies: 5
Views: 2715

Re: Controlling twist on Square Top sail

Hi parajacks, You want to be ahead of "most people" so don't do what they do. With adequate telltail coverage including leech telltails, trim the mainsheet and traveller to the positions where the greatest number of telltails are pointing aft, especially the leech telltails. Remember we all sail in ...
by Bill Roberts
July 23rd, 2017, 12:46 pm
Forum: Technical Forum
Topic: Controlling twist on Square Top sail
Replies: 5
Views: 2715

Re: Controlling twist on Square Top sail

parajacks, Sailing downwind the twist is controlled by traveler car position and main sheet tension. A more centrally position car and less main sheet tension will increase mainsail twist. More down haul tension will increase twist even more. What wind conditions are we talking about? With a full cu...
by Bill Roberts
June 27th, 2017, 12:54 pm
Forum: Technical Forum
Topic: America's Cup Speed Difference, US vs New Zealand
Replies: 5
Views: 2781

Re: America's Cup Speed Difference, US vs New Zealand

Thanks for your comments gahamby. You are right on as to the superior sailing of the NZ team. Their % flying time was always better than Oracle's. Spithill had two over early starts and more penalties on the race course than NZ. In the last race Oracle took the lead at the start and held the lead pa...
by Bill Roberts
June 26th, 2017, 4:30 pm
Forum: Technical Forum
Topic: America's Cup Speed Difference, US vs New Zealand
Replies: 5
Views: 2781

Re: America's Cup Speed Difference, US vs New Zealand

Well, what do you think? In the last race Oracle was the first boat to the first mark. Tacking downwind near the end of the second leg, NZ drove over the top of Oracle and ended up ahead and to leeward. Then NZ was in position to jibe for the gate first and rounded at the gate first and NZ opened up...
by Bill Roberts
June 26th, 2017, 6:30 am
Forum: General Discussion
Topic: Pre-Bend
Replies: 9
Views: 4696

Re: Pre-Bend

So, what's up? Does everybody understand what "PREBEND" is all about?
by Bill Roberts
June 24th, 2017, 11:00 am
Forum: Technical Forum
Topic: Kevlar fabric tape on keels
Replies: 2
Views: 1846

Re: Kevlar fabric tape on keels

Don't use Kevlar. It becomes a mess in an abrasion situation. Test: Sand Kevlar with a very rough sandpaper like sliding up on a sandy beach. The Kevlar does not sand away but it holds on and turns into a steel wool pad. The resin goes away somewhat but the fibers stay and become a giant fuzzy mess ...
by Bill Roberts
June 23rd, 2017, 5:37 pm
Forum: Technical Forum
Topic: America's Cup Speed Difference, US vs New Zealand
Replies: 5
Views: 2781

Re: America's Cup Speed Difference, US vs New Zealand

Thanks for your input. The kink is not the trick. A smooth curve is actually closer to the ideal shape. Here is the NZ advantage: The NZ boat is WIDER by a couple of feet. Therefore the righting moment is greater on the NZ boat. Therefore the wing pressure and thrust are greater on the NZ boat and i...
by Bill Roberts
June 23rd, 2017, 4:27 pm
Forum: General Discussion
Topic: Spring Races
Replies: 10
Views: 4529

Re: Spring Races

There is a wing for each side. This race this year was a one tack port tack race, The wind was 12 to 15 mph. The forecast was 17 to 20 mph. Therefore the 30% undersize sails. We would have been faster with standard size sails. The Miami to Key Largo Race is an "anything goes"race. Therefore many mod...
by Bill Roberts
June 22nd, 2017, 10:24 pm
Forum: General Discussion
Topic: Pre-Bend
Replies: 9
Views: 4696

Re: Pre-Bend

Question: Does everybody understand mast PREBEND now? As long as you guys understand it. that's good. You all are the most important.
by Bill Roberts
June 20th, 2017, 6:25 am
Forum: Technical Forum
Topic: America's Cup Speed Difference, US vs New Zealand
Replies: 5
Views: 2781

America's Cup Speed Difference, US vs New Zealand

Why is the New Zealand boat faster than the US boat??? The reason can be seen by watching the two boats sail/fly. OK, Here's a hint: The two boats are flying straight at you, front view. What do you see as a difference? How much would the American AC Team be willing to pay for this answer? Answer: I...
by Bill Roberts
June 18th, 2017, 10:21 am
Forum: General Discussion
Topic: Pre-Bend
Replies: 9
Views: 4696

Re: Pre-Bend

Hello fjviols, I see much confusion here. PREBEND is a structural thing. It is not a performance thing. Prebend, ~3", tends to stop masts from inverting when carrying a spinnaker. Remember when the I20 first came out and owners were breaking masts left and right when flying spinnakers. THEY HAD NO M...
by Bill Roberts
June 9th, 2017, 6:36 am
Forum: General Discussion
Topic: Spring Races
Replies: 10
Views: 4529

Re: Spring Races

Hey Guys, Where are the comments on the race/the boat? Ever seen a sailboat average 23 mph for 42 miles in a little less than two hours. At times the boat was going over 25 mph and other times 20 mph. Was that a smooth ride or what? It wasn't wild and hard to control. It was a Sunday ride. Anybody o...
by Bill Roberts
June 4th, 2017, 7:06 pm
Forum: General Discussion
Topic: Spring Races
Replies: 10
Views: 4529

Re: Spring Races

Hi Guys, Here's a link to the video of the 2017 race.
https://youtu.be/cfrePYoHjtA
Enjoy,
We will do better next time with the video
by Bill Roberts
May 23rd, 2017, 6:20 am
Forum: General Discussion
Topic: Spring Races
Replies: 10
Views: 4529

Re: Spring Races

Yes, it was my RC30. The camera was located aft of the rear beam looking forward.
It was our first effort with a camera and we learned alot and will do a much better job next time.
This is a start.