rotating mast stay attachment

If you get a chance John any more detail, or links to diagrams or pictures, on those methods would be very much appreciated.

 

Mast Tang & Rotation Base Casting

I had occasion to rumage around an old cedar chest and found a few sketches from my old Firefly Trimaran project. So here I post the tang sketch and a couple for the mast base casting.

Note that the mast rotates on a graphiite reinfoced nylon ball. Its rotation center was placed more reward of the mast centerline so that upon rotation the trailing edge of the mast did not act to close off the slot between the main and jib sails. This casting also was designed to provide a pivot point(hinge) for rasing the mast from horizontal layout forward of the ball (mast laid out in front of boat and pivoted up from there.

This boat was also boomless so there existed no pressure by the boon to induce rotation of the mast...all the more reason to insure rotation and then limit it by a limiter. The traveler for this boomless mainsail was circular to prevent flattening of the mainsail as the traveler was let out to its extremes.

 

Thats looking a bit more like someone meant it to work!

The idea of the mast stays pulling the mast in the right direction seems to be a common theme in serious schemes.

I am a bit wary of systems that require the 'right' tensioning of the side stays - it complicates setup for a trailerable boat, and really shouldnt be required for a well engineered solution.

The forestay is still a problem, even though it is closer to the mast.

Thanks for that insight, it is very interesting

 

the bury photo

its strange how people jump to conclusions the boat mast shown is very familiar to me .the rig was first on my f boat and performed very well
in this pic its on a custom 6.5 jarcat the rig rotated smoothly and in total unison with the rotation bail it achieved every required angle without fuss or clunking , Whilst it performed faultlessly for over twenty years you are of course at liberty to make any assumptions you like

 

Umm - what are you talking about please ? I cant even see a post from you on this thread, let alone 'people jumping to conclusions.

Please explain ???

 

double stays??????????

I have a poor picture of a carbon fibre rotating mast off someone elses cat that illustrates the problem that I took to see what I was doing wrong. As far as I can see, they had exactly the same problem made worse by double stays (less room for shackles).

Well my friend you are as poor a photographer as a rig designer hold the camera still next time you try to solve the issues of the world .
This is Australias first fully autoclaved carbon mast, it has been performing flawlessly for over twenty six years without your erroneous input.

thank you to the members who private messaged me about your misuse of my work in this forum post, you might like to know many hundreds of satisfied customers equals a big internet presence to nip internet experts in the bud
Take a good look at yourself how can so many boats use this type of rigging in fact more than any other rotating system, and yet you personally cant get it right, post less and get out and do it in real life, and remember accountability for internet know all's is here already

 

There's a letter on the Mystic Seaport site where Francis says, to a later owner of Live Yankee,that the boat was very erratic and hard to get performance out of.

Are you sure it killed the class in Marblehead? I seem to recall from the Herreshoff letters that they kept on going? I do know that you're very sound on this stuff whereas I'm just going of recollection.

Of interest, Nat warned Francis by letter that his rotating mast gained an unfair advantage (effectively providing unrated area) and would lead to the rules being changed. While Francis was narked with the NYYC, one gets the strong impression that Nat, architect of the rule, felt that the NYYC got it right.

 

I have that same problem.
What is 'sowhynot' talking about :?: Where is this "poor picture" he is talking about ??

Edited
Aw so, just found the photo he must be talking about here http://www.boatdesign.net/forums/sailboats/rotating-mast-stay-attachment-30189-2.html#post317999
But still don't see a proper defense of his claims about a better way to induce mast rotation?
____________________________________

I'm sorry, I worded that incorrectly. He made no such claims, but rather insinuates that the old way of attachment is the best way, as he has had no failures. I would direct him back to this quote by myself:

 

I haven't time to go back through my notes right now, but I think it pretty well discouraged people from commissioning new boats while the old ones sailed on in declining numbers. I seem to recall that at one point a number of Rs were shipped off to the Great Lakes.

And yes, Nat was always cautioning Francis about his taste for complexity and gimmicks. The correspondence about Whirlwind is full of that. Nat's sailing model of Whirlwind is in storage at Mystic. There have been persistent rumors that the published lines are wrong, and it would be interesting to see what the lines of the model are. Halsey once told me he suspected that Nat had a larger influence on the Whirlwind design than most histories note.

Cheers,

Earl

 

sowhynot,

Please explain how you recognized the "firs fully autoclave carbon mast" from a picture I couldn't even recognize how the attachment was made?
Do you have a better picture?
What boat was this on?

What are you talking about?

There is not a recognizable picture in this thread about your comment as far as I can tell.

Personally I did not see anything that attacked anyone personally.
Perhaps you would like to tell us who you are?

Also, what F-boat are you talking about?

 

I took this as referring to myself -

"Take a good look at yourself how can so many boats use this type of rigging in fact more than any other rotating system, and yet you personally cant get it right, post less and get out and do it in real life, and remember accountability for internet know all's is here already"

If so, it indicates some kind of severe personal disturbance.

If not, it still indicates some severe kind of personal disturbance.

And as for this cryptic comment
"thank you to the members who private messaged me about your misuse of my work in this forum post,"

Seems like some sort of underground conspiracy.

 

the severe disturbance is a fraud making comments whilst admitting he has no ability to see it through , you may like your historical posts but others are so sick of the tripe they mailed me your post , i guess all forums have a potion of <insult/personal attack towards others removed>

 

Who and what are you talking too and about ??????

 

Its time to just ignore this person or thing.

Is this the definition of a troll?

Thanks to the moderator.

sowhynot has now successfully become the 2nd person on my ignore list.

 

I think you are onto it UPC - a new form of trolling.

I used to have an aged Uncle who would get very upset about things that no-one knew what he was talking about, and that he thought was perfectly obvious.

The most disturbing thing to me is that I had no intentions of upsetting anyone, and if I had made a faux-pa, I would be very happy to clarify and apologize for it. Impossible to do without a rational, detailed explanation of course.

Never mind, I will catalogue the whole thing in with the Marie Celeste - a complete mystery.