cheap and simple rig

Well Eric, some of this has been discussed on this forum in the past. I guess you either forgot the outcome of that or are willfully misrepresenting things. The IOR section you mention (again!) did not have anything to do with stayless rigs. It also did not preclude Freedom 40s from being measured and receiving valid IOR rating certificates.

The Marchaj quote has nothing to do with "constraints posed by wires in rigs". The measurements of the sails (including headboards and battens) simply attempted to rate the speed increase due to the aero improvements. The rule did not "prohibit" the use of long battens or an oversized headboard.

Rating rules still attempt to rate the speed of sail designs. With the current materials and design tools it is possible to get extra performance that exceeds the rating hit, so people are using big head sails.


Trying to have any discussion with these true believers is exactly like trying to have a discussion with religious zealots. They ignore facts and set up strawman situations that "prove" their position.

If there is an afterlife I'm sure PT Barnum looks down and smiles every time they tell their tale. Joseph Smith and L. Ron Hubbard would undoubtedly be standing right next to him.

 

Concur

 

A kite.. anyway the rig is cheap, dunno how much the kite.

 

sailor305, for a smaller catamran, a twin unstayed mast or "biplane" rig might suit your needs... simple, cheap, has a sail pocket etc... you could build these masts yourself without too much trouble...

 

OK, my recollection was correct but I agree he also restated the 'conservative' bit without the qualification. Not being a mind reader, I'll refrain from speculating on whether this is a typing oversight or he really meant to include all sailors.

Now, my take on things is that you're stretching a long bow. You're basically claiming that as people sell up stuff and go off sailing, they therefore can't be considered to be conservative as the 'conservative' thing to do would be to stay with the herd and stay home. Sure, I agree with you.

Not the point though.

My take is that Eric was clearly referring to cruising sailors being conservative WRT their equipment and rig, which is something different. So basically your above argument is dragging in a straw-man to debate rather than the point.

Anyway, if someone wants a cheap & simple rig, the first steps are to define 'cheap' and 'simple'. Until you've done this it's pointless. I notice the OP has clarified his needs now and fulfillment isn't IMO going to meet *my* definitions of cheap and simple so I have nothing further to offer.

Other than I'll rig my 12m monohull with all new rig & sails for less than $10K. It'll be cheap by my definition, but probably not simple in terms of freestanding mast etc.

PDW

 

Gooday Doug & 'some others'.

Doug - some are not able to compare rationally - about anything - that would require a rational - logically - well balanced -attitude. & that just ain't gona happen from those kind of people. Their 'bend' in life is to be totally bent. They see anything & everything anyone else knows as a direct threat to their personal inabilities. They feel they must pull everyone down to their lowest common denominator. We all don't need to follow them down that path.

I've made this suggestion a few times now & I'll do it again - just talk to the people that have something positive to offer & leave the rest of the 'no-hopers & nay-sayers' out of the discussion - - then we'd all be better off.

Empty vessels make the most hollow - usless - unessary - annoying noise.

Now to all those that are making a valuable contribution to this 'forum' subject - I say a big thank-you. Enjoy you week & being alive - look to the sunny side & let those who wish walk in the mud of despair continue without dragging others way down to their level. Ciao, james

PS. I do note that 'sailor305' has acknowledged all of those that have assisted him in acquiring more & valuable information - to help him make a better choice & I'm sure we've all been more than willing & happy to help guide him - along his chosen path. My thanks also to all those I've been fortunate to learn more from - I'm also very grateful. jj

 

Gooday 'groper' It's no wonder that those 3 have such big smiles on their faces. WOW Isn't that just the tidiest little machine ever ! ! & so KISS is the rig. They sure do look like they are - moving right along - I'm sure we'd all love to be there enjoying their thrill. Again wow ! ! !

I sure gota look into that 'rig' set-up for ease of handling - looks like a KISS cruising rig - for sure. Talk about a truely 'pocket-rocket' ! ! ! Thanks for posting, ciao, james

 

On a 1920x1080 30 inch monitor with a 2GB Nvidia card I can't see any big smiles, to me they look pretty bored and unengaged. If I was on that boat I'd certainly be visibly smiling. I'd also fix the messed up reefing lines and keep an eye on the sail trim as the telltales are showing turbulent detached flow. The boat is probably sailing at 60-70% of what it should be capable of. Can't figure out why they are reefed given the flat water and low winds either.

Funny how some people see what they want to see, and others see what actually is there.

Simple, cheap and easy to build? Perhaps "easy" for someone with serious experience. Perhaps "cheap" if you were following behind a composites delivery truck and a skid of carbon fell off. Oh, and a badly loaded truck from West System as well.

What do you use for a mandrel? What kind of shop has 30' of straight, level clear work space? Most garage shops don't have vacuum bagging facilities or prepreg experience. Most home builders don't have the experience to decide on layup schedules that will result in usable spars at reasonable weights. Most home builders don't have the engineering experience with composites to even design a mast. I can't tell if these masts have built-in bend for certain, but it sure looks like it - that can't be easy to get right. The I-beam curved and tapered booms don't look like a home shop item as well. It would be interesting to see if the masts are using a non-round section (under the sleeved luff) as well to facilitate better flow and less detachment. If they aren't round the build goes up several orders of magnitude in complexity.

If this is a non-round, curved tapered composite mast (which is probably optimal for this application) I see $10,000 in NRE tooling a metal mandrel. I see a professional engagement of a mast designer to get the material schedule right and build a first sample ($5000). Then I see a skilled amateur possibly building two units for perhaps $1500 each (while they are losing paying time working at their day job). Certainly not cheap, not easy or simple. Just educated guesses, but I would encourage anyone interested to come up with better numbers.

It is easy to write on a web forum that things are easy, especially if you haven't done it. The experience of people that have done it can't be gained without lots of mistakes, wasted material, broken attempts and non-recurring investment in facilities and tooling. It isn't easy, it isn't cheap and it isn't simple. Generally, you can't cost effectively produce anything on the first few builds - it takes time to figure out how to do anything efficiently and without trouble.

Although I understand the lollipops, rainbows and pink polka dotted unicorn crowd want only encouraging, supportive and cheerful people here, I'd trade them all for someone who actually knows what they are doing that can provide accurate and succinct advice - even if they are crusty, mean and sarcastic. This is a design forum about building boats, not a daydream parlour for people to find their happy place.

From my perspective, the original poster may have "thanked" people for input, but in actuality they have ignored any advice that didn't agree with the ideas they had pre-emptively chosen. This thread is more a request for validation of the poster's choice than an actual request for information. Repeated requests for information about the hull, it's design, SOR and numbers have gone unanswered.

Since James above has already asked me to leave and start my own forum, I think I fall into his bad books. Who's contribution actually is more worthwhile? The professional rigger who knows more about rigging because he's worked on everything from 1950 forward (with 15 rep points) or the high post count amateur (with 900 rep points) who has rigged one or two boats? I know which one is "nicer" on the forum, but I also know which one's work I'd trust more offshore (and it isn't the "positive and happy" one).

As an amateur boat builder myself, I'm always thrilled to see people of Rob Denney, PAR and Eric Sponberg's calibre posting here. Even if there is contention and disagreement.

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CutOnce

 

well, instead of being negative and offereing nothing constructive, how about we delve into the design and construction of a free standing carbon mast? so instead of rhetoric, we exchange facts and ideas?

Fact, you can design a mast based on the sailing loads and maximum righting moment of the said yacht it is to be fitted to to arrive at a maximum bending moment. You can calculate a reasonable engineering solution to a simple mast design, by using the simple section modulus method to determine a wall thickness for a given mast section.

http://en.wikipedia.org/wiki/Section_modulus

A brief overview on the process of this calculation has already been discussed on this forum by Eric Sponberg here;

http://www.boatdesign.net/forums/multihulls/calculating-beam-scantlings-catamarans-13137.html

You will also need the mechanical properties of a typical carbon laminate, and this can be found in multiple places on the web, i like to use the values listed toward the end of this document, which also has a number of other handy equations for composites design;

http://www.hexcel.com/Resources/Dat...eets/Honeycomb_Sandwich_Design_Technology.pdf

A pair of small masts, is not very daunting and the ones depicted on the photo arent much more than a pair of windsurfing masts on sterioids...

As for building, again there are many hints on how to do it already floating around on this forum... gary baigent has given much detail on his tensioned ply mast building methods, which could also be used with thin composite laminates instead of ply. personally i would look wind turbine blade manufacturing processes as i like using resin infusion build methods. so, i would essentially look at infusing a solid carbon box section, then wrap a thin laminate around it as an aerodynamic shroud.... this could be produced quite easily in a few steps on a long flat table mold.

The only limiting factor, is confidence in yourself, and the ability to research what you want to do....

 

Nice post, and I agree with most of what you are saying. If your objective is to build everything yourself for knowledge gain or satisfaction, your post is spot on. If your objective is to cost-effectively build a strong, light and functional boat in a time/money optimised fashion I disagree and think my post was quite reasonable and not negative at all.

Judging what jobs you can do cost and time effectively, and what jobs are better farmed out is a critical task and requirement to actually finish boats. Most boat building exercises do not get completed. People buy plans, some smaller number start builds, many complete their builds very late (with a different wife) and a very few actually build good boats, on time and on budget (with the same wife as at the start).

In my opinion composite masts are one of those speciality areas where it makes more sense to buy from an expert than build your own. The amount of information, engineering and experience required exceeds that of most amateur builders as well as the likelihood of a sub-par result on the first go. Paying Southern, Forte, Seldon or whoever for their expertise is a better bargain than taking on a huge challenge. Spar manufacturers all produce ever-cheaper composite spars as they get better at doing it. You can't compete with them in any way other than personal satisfaction. They buy materials cheaper, they use less time and labour, they know what works, they stand behind their products and in the long run their products cost less, even with their markup.

Practical engineering is choosing a careful path to an objective that weighs every intermediate step in terms of result quality, cost and time. If the objective is learning, personal satisfaction and the journey, your post is correct and mine perhaps negative. If the objective is getting to the goal in a cost and time effective fashion, my post is certainly solid, positive and worth consideration. Both are right, but different.

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CutOnce

 

Perhaps you are underestimating the process of development that took place in the windsurf industry to bring filament wound masts to market successfully as a dependable product? Your comment is rather dismissive in scope.

I'm sorry to tell you, but the process is a good deal more than the simplistic effort you indicate. Perhaps you could demonstrate the appropriate design/build steps through a personal blog and we can all follow along. Then, when the sticks are built and installed, shoot some video of the sailing characteristics demonstrated by your windsurf masts on steroids approach.

I think that perhaps we have gotten so used to having techno goodies about, that we have driven right past the process as it really takes place and plopped ourselves down in the marketing VP's comfy, leather chaired office instead of discovering what actually goes into the product as a pragmatic reality.

 

The small sticks shown in the picture posted previous, ARE a very simple mast... they are also quite small, and therefore the risk of attempting to build your own is minimal - my best guess is there is probably not more than $1000AUD worth of carbon in each one for that 8m cat... i would definately try building them myself - if thats what i needed - but my experience with composites and research ability may differ from yours...

On the other hand, if it were a +60ft tall single unstayed mast of much larger proportions, is a totally different ballgame. Eric has stated he has never designed a single free standing mast for a yacht smaller then 40ft- mainly because the $5000USD design cost itself cannot be justified for such a small mast in addition to the build cost.

In between, you can buy the plans and build this for $8000AUD, ($3000 for the boat plans, $5000 for materials to build the carbon mast) the plans are for the design for the whole 15m boat including the freestanding carbon mast and booms...





Rob Denney will help you along the way if you run into troubles and estimates 100hours of your time to build the mast (probably a bit optimistic IMHO)...

How many more excuses do you need to avoid this "huge chanllenge" or am i still lounging in the marketing VP`s leather chair?

 

It appears that in your haste to reply you have forgotten that it was you who said it would be an easy task and not me. It was you who said they... "arent much more than a pair of windsurfing masts on sterioids...(sic)"

So, issuing challenges that attempt to reverse the paradigm are not appropriate. Show us, Groper, that you have the skill to reference the build of these two beautiful sticks all on your own. We are all prepared to stand back in awe as you put them before us and then demonstrate that they actually work as intended.

In short, put your money in place of your mouth, or at the very least, come to grips with an apology and step away from the soapbox out of respect for those who do have the skill and cash necessary. There's a reason why mast builders of this style and material type exist, Groper.

So, what's next for you? Will you be building your own four stroke outboard? After all, it's just a collection of precision cast, molded and machined metal and plastic parts that are easily achievable by any bloke with a shed and a willingness to spend the next five + years in time plus the cash needed, acquiring the tools and skills to do so...? Then voila! There you have it, your own four stroke engine for the boat along with all the metallurgy, machine shop acumen and plastics technolgy understanding at your finger tips for even more adventurous tales in the future. ;-) Any eighth grader can do it if he only dreams it so.

And yes, you are still lounging. Time's a wasting my boy.

 

Indeed there is a reason, people spend too much time in front of the TV rather than learning to build what they need. These people are not the kind of people that should attempt to build a boat, a mast, or anything, but rather go and buy one as they will probably never finish what they started lacking the energy and drive. Other boaties, have so much cash they dont need to build things themselves because they can afford anything they want and dont even seem to notice the money...

The people that do have the confidence start something, an open mind with ability to learn, and tenacity to finish it, might come to a forum like this for inspiration... Someone like you, would be better off posting in "mastsales.net" or "saveyourcashandbuyit.com" where people might go to have lazy attitudes pressed upon them, "just because i cant do it, you cant and shouldnt either"...please!

Whats your line of work? building masts i presume? you sound like one to come here to scaremonger and protect your business interests...

heres garys home built wingmast, 15.5m length and light as a feather for his home built and designed tri foiler...


its not freestanding, but shows gary is the kind of guy to have go, not sit back and watch the TV... Gary has posted the designs and contruction of tensioned ply and carbon wing masts in this very forum (the correct place for this type of thing)...

Why is it, you feel its such a huge challenge anyway? are you burdened by past failures or commercial interests, or...?

 

Nice for Gary and all, but it's not the type of mast you argued as a simply constructed home built project. Pretty tough to argue a topic with you when you keep moving the goal posts around. How about you stay on the original comments?

How many folks here can have a go building a decent sized filament wound stick and do it with enough quality that it will work when out on the ocean? You mentioned Rob. Why do you suppose that he builds masts for customers who are only wanting a mast for their project? You're talking about a critically important piece of kit there that has significant engineering connected to it to work properly. If it was so easy, why does Sponberg get the fees he charges? A quality mandrel for this kind of project is a serious chunk of change and the stick will only be as good as the core on which you wind the tow.

It's really simple, Groper. You are on a public forum making flippant remarks about structural items that have great importance when it comes to the success of a sailing experience, the value of the boat, the safety of the crew, etc. I think that you owe the process more respect when the building of a filament wound stick that is well made is not a simple task for the average dude who might build his own boat. That you are not accepting the challenge says everything about your confidence in the matter.

Moving on now.