FX-ONE tuning help

That's a bummer Jim. When I took mine apart I spent probably five minutes just turning it back and forth, going a little bit farther each time. I was real fortunate neither of mine broke.

What is this mast stepper you're asking about? My own opinion is that most of the contraptions aren't worth the hassle. When I go to the lake by myself, I bring a 6' ladder to set the mast on so it can hold the diamond wire clear of the rear crossbar while I get other things ready.

I don't use the pin. After a stripped mast ball last year I decided I don't want to drop my mast again. I tie off a short piece of line from the dolphin striker post to the mast rotator.

After the mast base is secured, and the mast is resting on the ladder, I take another line and tie it to the forestay, run it through a block that I have at the base of the mast crutch, and then to the spinnaker halyard cleat.

I lift the mast like normal and pull up the slack on the line that is tied to the forestay. Then cleat it. Now I'm free to jump to the front of the trailer and pin the bridle/forestay. Loosen and remove both of my safety lines, and then tighten whichever shroud I use to tension the rig.

I don't know what the actual weight of the FXone mast is, but I swear its easier to step than a H16. Mostly because I hate the hinge setup. Point is I get on the water pretty fast. If I don't rig the spin, or bother with the wings, (some what dependent on where I'm launching from), I can go from trailer to water in probably 20 minutes. With everything else I'm on the water usually in 40 minutes. This year I'm going to leave the spin in the bag, and the pole on the boat.

I just reverse the process when putting it down.

I would highly recomend this for any cat trailer. Having a deck on the front makes rigging so much easier, plus you have a place to throw wet gear or something to stand on when changing. I hated straddling the frame members on the other trailers I had. When I had this one built it was one of the key things that I wanted.

Without a doubt that is one absolutely amazing trailer. It looks comfortable -- which is the end result that almost everyone wants when it comes to boat rigging.

About the mast stepper...

Found a great line out of one mast stepper review:



Emphasis mine.

Like that trailer of yours, all I am after is comfort and ease in some situations when raising the mast. The FX mast is light. I don't mind raising it myself, but I'll take brains over muscle. Your method sounds stable.

When it is needed, I think the test of a good mast raising setup is that you can halt the process any time. In other words, with the mast halfway up, be able to stop, let it rest momentarily if I need to untangle a line or something, and then continue when am ready.

Everyone seems to have a different opinion on this one though...

Phil Berman in his book suggests rigging the boat on land and then tipping it over so the sail is parallel to the ground and then doing an initial tuning on the sail. All cats, he says, should have a draft at about 30 to 40 percent from the mast, IIRC.

Sound right?

Mast:
Spreader angle
Diamond wires
Rotator
Mast rake

Sail:
Battens
Outhaul
Downhaul

Rudders:
Toe-in
Load (tilt forward or aft)

As far as the above list goes (from earlier), some things obviously you can adjust at the waters edge and only a few things you can adjust on the water. You could ruin a day's sailing by playing with the rudder settings unless you really school yourself on the adjustment techniques.

On the water, the mast rotation, for sure. The downhaul, some. The outhaul on the FX isn't much, it appears. That's about it, it looks like.

Only the mast rake, diamond wires, spreader angle are quickly adjusted at the waters edge... Battens? If you wanted a flexible set vs no flex, I suppose.

I still like Rick White's power vs speed setup -- which is against the above three set by a table like the tuning guide suggests...



Although, as quoted, besides setting up for power or speed, there is still that need to depower...

JJ,

While a lot of the information is still relevant, check the copyright date, this book applies to Dacron sails.

This book also applies specifically to the Hobie 18 diamond wire set up which is quite different from most modern cats. Look to F18, or other (modern) classes, for info on matching your sails luff curve to your mast.

Recall you wont be "batten tuning" the draft in your sail much as it is made of Mylar.

_________________
Sheet In...Max Out
www.fleet297.org
sailflatlands at gmail dot com

Karl, any reaction on this from Wouter from the other forum?:



Never know exactly how to take his remarks, but usually there are some interesting parts.

@ J Eaton

My curiosity was whether checking sail shape was still done by anyone that way -- by laying the boat over and looking at it. At this point, more as a learning experience so that the peculiarities of the sail are understood. It is under no-load that way. And max draft can be measured... Basic tuning, not intermediate or fine tuning, I guess. I caught your earlier post...

Catamaran Sailing From Start to Finish by Phil Berman (never gave the title) is the revised edition, 1999. And, still, wouldn't be surprised if some things aren't revised. The H18 diamond wire thing...?

Be nice if Matt Miller would post his "Matts Method of measurement" on his FAQ forum.

...wrong book...sorry!

I take this littany of information and wonder...how much of it is just explaining what I can adjust and how much of it is what I need to adjust? In other words, based on my total crew weight and typical sailing conditions, I will be able to get very close to an optimum setup, except for ranges way below, or above, these conditions. When I do this initially, I eliminate a lot "mind games" in my own head and can concentrate on getting optimum performance at a base setting and then adjust one thing at a time to guage any differences. Realistically, I'd have to have some pretty sophisticated measurement equipment to notice some difference (even boat-on-boat tuning may be skewed as how do you know things such as sheet tension and crew weight are/were identical?...you don't).

Starting with your first set of adjustables:

Mast:
Spreader angle
Diamond wires
Rotator
Mast rake

A combination of Spreader angle and Diamond wire tension will give your mast pre-bend (and here inject) take Wouters' point about the mast, it's a shortened Tiger mast and will be stiffer, and harder to pre-bend in the major axis. This is what you want to do for a base setting...get enough bend in the mast so the luff curve depth of the sail is close to, or the same as the masts'. Hobie has probably taken in to consideration the stiffer quality of the mast and built less curve in to the Main (comparitively speaking). If your sail and mast prebend are close to the same downhaul will work freely, and give you the on the water adjustment of flattening the sail (and without going in to more on theory, that's enough said here). Diamond wire tension can be loosened or tightened above your base, but since the effect on this shorter mast will be dampened, I think the effects will be dampened as well.

Rotater is an on the water adjustment, pointing somewhere around shroud will be base until heavy air then pointing further aft (up wind). And full off downwind.

Mast rake, Jeremy or Karl can probably give you a base setting for rake. Adjusting one hole either way (for conditions) may be benificial. On most boats, you find the rake and then leave it alone.

Sail:
Battens
Outhaul
Downhaul

Battens, we touched on this, snug up and then forget it.
Outhaul, Karl touched on this I think, find a base setting upwind and off down, forget it.
Downhaul, your friend upwind to flatten the sail (decrease draft/power) to keep the hull from popping up, downwind off (don't forget to release dowhaul BEFORE turning downwind)

Rudders:
Toe-in
Load (tilt forward or aft)

Toe-in set once and forget, maybe check once or twice a year?
Load (or rake) if it's not close now I'd be surprised. If once you start sailing the boat you got excessive weather or lee helm address in a different post

So OK, we just eliminated six or seven of your "daily" settings, leaving you downhaul and rotator as the only ones to play with. You'll find the right place for the rotator pretty quicky, really only leaving you downhaul to play while your sailing, and as stated in a previous post, unless you have a third arm, or crew, how are you going to adjust/play dowhaul on the water? I'd set it first to remaove all wrinkles from the luff. If in gusty conditions (and still popping a hull) you'll want to pull on more downhaul (and maybe more again), then decrease rotation (if that doesn't solve the popping), and then travel out the main (if that doesn't solve popping).

I despise spending time on the beach trying to tweak my boat for a miniscule difference in performance on the water, especially since for the majority of conditions downhaul, rotator and traveller will take care of it, IF my base settings are close.

_________________
Sheet In...Max Out
www.fleet297.org
sailflatlands at gmail dot com

I Think I'm one of the few people on Catsailor that genuinly likes Wouter. Most of his posts are over my head, but they are always informative. He is also one of the few people on there that will give you a subjective answer on boat related subjects.

The FXone does handle weight really well. Getting the bows pushed in is important, especially going to weather, and can be hard when at minimum weight. The minimum two up weight is something like 258#'s, which is probably about perfect the weight for running with the jib. When I was up on Lake Superior we were probably about 330#'s, and we didn't have too much trouble being able to keep the bows out for the most part.

I thought it was kinda funny that I proposed a two up rule change that was almost identical in every fashion to the one that the Germans proposed.

As far as tuning the sail/mast goes you gotta learn the boat first. If you don't you won't really know what the changes you are making are doing.

Hi JJ and Karl,

To answer your question about max draft of a mainsail ... my sailmaker friend (who was the sailmaker for two Australian Syndicates in the America's Cup) makes all his A-Cat mainsails so that the max draft is between 40-45% of the cord length of the sail ... I believe the actual measurement is closer to the 45% number. I can not remember (positively) if the percentage changes slightly as you move up the sail or down, but I "think" as you went up the draft should move aft .... slightly. For example start low at 42% and be at 44% at the topof the sail.

Now, we used to "shave/tune" the battens so they would bend/curve at the percentages that we desired for the H16 and H18 dacron mainsails. Tony ordered a new set of battons for my P19MX several years ago and he specified to the batten maker exactly where the pocket/max draft of the battens should be positioned ... this mainsail was made by Smythe and is constructed of Pentex.

The method discribed in Phil's book (and Welcome to A-Fleet) is the way most of us ol'timers have "tuned" our sails. I set my boat up in the backyard and turn it on it's side and measure away. I take measurements with different mast rotation, downhaul, and outhaul ... starting out just changing one adjustment at a time ... then trying two adjustments, then three. The downhaul and outhaul are easy to measure, the mast rotation was the toughest ..... I eventually made a large protractor and taped it to the tramp so I could measure the angles.

Next step is to take the boat the to the water and do some "speed-runs" using a GPS and see which settings make the boat point best both upwind and downwind ... go fastest ..... etc etc.

But first you need a baseline ... before you make a bunch of changes ....

And YES, I believe Phil's tuning quide is dated especially the diamond wires ..... (I don't care WHAT they say ... the Hobie factory sails for the H18 have varied over the years ... I have several different production date sails to prove it produced from 1978-2006!!!!)

And Yes, I like Wouter also ...... a very, very, very smart person. He is a HIGHLY educated engineer/professor who can analyze a technical problem "completely" through. And his general knowledge of the world is impressive. Someday I would like to meet him in person ..... Upon careful thought on his arguments I have yet to be able disprove his position/conclusions (I've been wrong every time so far) except for his choice of beverages ... he likes "Madiera" I've been told ....

_________________
HarryMurphey
H-18 mag/ #9458
Fleet 54 Div 11

Eye candy, after tarp off because of snow weight.

Amen to that. A lot of those mind games comes from conflicting expert advice (not yours!). I like Wouter's comments for that purpose, because he adds a "why" a lot of times to his "what" -- although not all the time. For example, he uses "stiff mastsection" to describe the FX mast. I have no idea why he says that because he doesn't say.

The FX mast is about a foot taller than the H16 and about a foot shorter than the Tiger, so he must be talking about the thickness or girth of the mast.

Wouter reminds me of those guys in the auto shop class in high school who could tell you the details about every kind of carburetor on the market. I assume he is typical of the European sailing club. Like others, I don't know where he gets all his firsthand "research data" sometimes, but he is informative. Within limits, I support him simply because he is a target. Nothing more fun than backing an underdog...



Yeah, and I am just being a little lazy here. Trying to pull as much information out of those, like you, who are experienced to come up with that baseline.

This was mentioned in an earlier post about tuning an FX:



Interesting stuff...

Thanks for the posts. I got remarks and some arguments to pick, but work gets in the way. I will go to one and two sentence remarks and stop the long litanies.



Yep, and Wouter agrees and says why, doesn't he? Or not... I don't understand the full meaning of that... but I am puzzled why the 17 people are such a tight group.

If the FX does not meet class rules, there's the reason. But it ain't like there are 200 Nacra 17s all ticked off about 200 FX's jumping in their fun off the coast of France or something...

A couple of things will determine the stiffness of the mast. The dimensions of the mast itself, width and depth of the section. I'm not sure what effect the shape has on this, but it must in some form or fashion. If it were perfectly round it would have equal stiffness in all directions. I'm guess the tighter the radius' on the shape the more spots it will have where it is stiffer per given angle of pull. Makes sense in my head, tough to put into words..... The cross section of a FXone/Tiger mast is frickin' huge compared to a 16.

Diamond wires also effect the stiffness of the mast, both in rake of the spreaders, and tension on the wires. The FXone has a smaller diameter diamond wire than the Tiger what kind of an effect and to what degree that actually has, I don't know.

The problem is that the the extrusion on the FXone is the same as the Tiger, but a bit shorter. The Tiger main is fricken huge compared to an FXone sail, and the Tiger is a 725lb boat, and the FXone is a 487lbs boat. Thats a big difference in weight.

Like I said before, I've got a ton of spreader rake, and I'm running quite a bit of diamond wire tension. 48 is the number that comes to mind on a Loos gauge, but that was better than 6 months ago the last time I checked it....

Does anyone know if it is the same mast as the Fox?

Jim, any interest in going to Mid Winter's East? There is one locally, If you and I went we'd get our own start. I might be able to go now. Not 100% but I maybe hitching a ride so the price is a bit easier to swallow.

I would give my eye teeth to be able to get Mid-winters but work is grinding thanks to all this fun economy.

Did your boat come from the Sandy Hook Club in NJ?