Actual mast rake

[Barry Pyeatt]

hborger,

It looks a bit off to me as well. More rake than it should have, but that is a tricky thing to estimate by just looking at the angle. Stick your angle keeper down the hatch and set it as built. Then measure it and see if it is different than designed.

One indicator to me is the height of the aft end of the boom at rest. It looks too low unless the sail is not made to measurements. Another indicator to me is the angle of the forepeak and the angle of the gaff. When the angles are correct it is almost the same. Also the angle compared to the front of the cabin looks like it is raked back rather than nearly parallel to the cabin front. Small differences are hard to see off hand. Measure it and be sure. Then you have something to go by.

I totally respect what Tim has done with his Weekender, it seems to be well thought out and it seems to work well for him. I think it would be fun to sail.

I don't however feel that it is something that anyone should just take off and try to do on their own to copy it unless you have quite a bit of experience in tuning a rig and knowing what you have accomplished when you get it done. In other words, not something for a first time builder or novice at sailing.

The Weekender as designed and if built to the plans will most likely exhibit good handling characteristics once you get used to handling it. It isn't a big boat, it is a little boat. It doesn't handle like a lot of other boats the same length. In some respects it handles better and in others it doesn't seem to handle quite as well. But I think that most of that is learning how to tune it once sailing it becomes second nature.

As designed, the boom sets comfortably just above my head, and I'm 6'2". If it hangs lower, something probably isn't right.

I've seen the issues in tacking first hand. Learning how to keep the momentum up while tacking doesn't come quickly for a lot of newbies.

Even those that are used to sailing other designs. It takes some getting used to. Learning how to do that and handle two jib sheets while tacking can be a really interesting learning curve for some people.

For what it is worth, I don't really believe that there are any two Weekenders that are built exactly the same. Or exhibit exactly the same characteristics under sail. Sails are different, materials are different, measurments are slightly different and the rigging is slightly different on all of them. Fortunately the design is very forgiving and small changes generally don't really degrade the ability of a builder to have a really good time with learning to enjoy the boat.

The discussions here are more or less for those that have tried the standard rig and just want more from it than it gives without changing things a bit.

Mine will rig is different than Tim's or Frank's or any that I've sailed on thus far. I've incorporated things that I know that I will want to have for ease of handling as well as good performance. I want a boat that will give a good show of itself and as my learning curve continues to climb, will hopefully perform better than those that I've been on. Not that any of them have been poor performers. But all of then have needed some adjustments to rigging to tune it better. All of them will continue to need it.

It is my opinion and many others as well from what feedback I get too, that you go back to the basics when you have something that bothers you about how it handles. First thing I look for is angle of the mast how other spars, sails and rigging are set up. Then how the rudder and steering system feels. More often than not, the cause is right there in the basics.

Generally it is easy to correct and then handling is noticably better immediately.

A mast that is more than about 3 degrees off in mast rake coupled with a boat that sails bow high is likely going to have more weather helm than you would want. Get the bow down and the mast top will move more than a couple feet forward. Yes, it doesn't do a lot to change the COE. But it does change the balance considerably and the handling too. Correct the mast rake to nearer to the 93 degrees as designed and it becomes better yet.

Then it is a matter of tuning the rigging and learning sail management under varying conditions. That takes some time and is a lot easier if you have someone that has gone thru the steps and can evaluate the changes as they are being made. One change at a time rather than a lot of changes at one time. You just don't really know what is working for you or against you that way.

I just know that when you can be sailing when the other boats are still sitting idle makes the Weekender a lot more fun to be out in. And even in high winds, learning how to reef and manage sail trim makes even heavy water sailing fun. But you have to really understand what is going on to do it. Give it time before making a lot of changes, just because someone else has done it. That doesn't mean that they aren't good, but I'll give you odds that the conditions they sail under are significantly different than your own. And their expectations are different than yours as well.

Good discussion!

[capt jake]

I find this topic compelling. I never really gave the geometry much thought in this area. I did raise my mast during construction by about 9" (if I remember correctly). At 6' I still have to duck for the boom ever so slightly, but the performance seems fine. I will take a closer look at this next time out.

BTW, according to the spell checker, I am spelling teh correctly.

[PAR]

Every Weekender I've been aboard and most I've seen on line have been built heavier then they need to be. This has the unforeseen effect of causing her to drag her transom, well immersed, which will reduce the performance abilities and increase the weather helm. It also can cause the bow to lift when meeting a chop, leading to pounding. Two complaints I see often on line.

Flat bottom, skiff like, sailers such as these need to be sailed up right (limit the amount of heel by shifting crew weight) and kept light in construction and stores brought aboard.

If rigging adjustments don't sort out the helm pressure then a skeg or addition to the deadwood assembly aft, could well reduce her rudder angle. Additional headsail area can also be added. These two things; moving the CE (Center of Effort - pressure point on the combined sails) forward and/or adding lateral plane aft will solve any helm balance issues. This will permit the rudder to work in the favorable 2 to 5 degree window of efficiency necessary for good feel and safety, but not act like a brake or be stalled from an angle of attack that's to high .

Typically the CE is moved as it's the easiest to do, with mast rake usually, though more headsail area or decreasing the mainsail area can also have the same effects. Cutting up sails or getting new ones isn't a very cost effective technique when using trial and error methods. Mast rake will fix 95% or better of the problems found in balance (balance is the relationship between the CE and CLR, which is called lead) The correct lead isn't science, like a lot of design work is, but in fact a good guess by the designer. The lead for each boat will need adjusting to fine tune the boat, or correct a bad habit or two she may develop. Amercia's Cup boats spend months fine tuning the lead position.

Below is a better idea and one I'm incorporating into my build.

W1.bmp

[Guest]

I would think that an easy way to figure out lead and its placement would be to take the original hull and bolt samples at certain points, along side of the orginal keel, built to design and sail under similar circumstances. I am not sure the the full keel, as drawn is a benefit for handling in certain conditions such as current sailing, no matter what the prevailing wind conditions. I know I maybe going out on a limb here, but from a fair amount of reading on the charateristics of handling upwind, your drawing maybe an inprovement. Now take this with a grain of salt since I am not an expert in the field of sailing, but have attempted to deal with our east-west waterways and our southwest winds and its bear with the shallow draft boats, even with a small vee with the barn door rudders and large skegs.

[PAR]

Lead is actually reasonably easy to figure out, but you must have an accurate lines drawing and sail plan. In truth, the lead moves around underway, but general positioning can be done with simple geometry. A quick, but not so precise way of finding the CLR is to print and cut out a drawing (on stiff board) of the underwater profile of the hull and appendages (less the rudder). Using a pin, try to find the point the shape balances on fore and aft. This is the CLR, a bit rough but close enough. The CE can be calculated by finding the centers of the sails and then the center of the sail plan, which is simple geometry. When both CE and CLR are found, mark them as vertical lines across the LWL on the sail plan or hull profile drawing. The distance between them is a percentage of the LWL length (5% of the LWL, for Weekender as an example)

Each rig and hull combination will have certain needs in a lead requirement to balance the helm properly (this is the guess work part) There have been attempts to catalog the configurations (centerboard/flat bottomed/low aspect gaff sloop, canoe body/fin keel bimu sloop of high aspect, etc.) but these are only other folk's good guesses. Though they can be a good starting point, experience with a particular type, rig and previous successes are the only way to nail it down, pretty close. It will still require fine tuning, especially if you've jumped well out on the design limb in various areas of the design.

Pointing ability is mostly a function of aspect ratio, in both the appendages and sail plan. The higher the aspect ratio, the better to windward you should be able to go. Hull type or shape can be a limiting factor, as can other things, but generally . . . The Weekender/Vacationer have quite low aspect sail plans and keel profiles. The sectional shape of the keel isn't very efficient either, this coupled with the, generally over built construction (heavy) low rig and pivot point under the hull, conspire to keep the boat near 100 degrees, before it has to pinch, limiting their windward ability. Tim Diebert's wonderful job of cut down deadwood assembly and dagger board have shown great improvements in handling, maneuverable and pointing ability. This is a perfect example of reduced drag and centralized appendage. The forefoot is rather bulbous and under certain conditions will restrict turning. The deadwood assembly area is well forward and has no drag (fore to aft slope) which leaves little but the rudder input to force the bow over. Every design I've seen (I have thousands in my data base) have a defined appendage or use drag (keel sloping aft to the stern post) this permits the boat to have the turn started with the rudder, then the sail plan pivots the hull around it's appendage.

The drawing above is for a friend, who's boat I'm building. I'm building one for myself, with the same profile and foil shape, but also with a "slice of pie" centerboard. The centerboard will be housed entirely within the deadwood assembly, so not to intrude into the cabin and cockpit spaces. My boat will also have the same area in sail, but taller (longer luffs, same sq. footage) these changes will increase both the aspect ratios of the appendages and the sail plan. My boat has been converted to a true tape and seam construction, which will save some weight and be stronger.

[Frank Hagan]

Par, as always, you bring a great perspective to all of this.

We have to remember that all of the formula and calculations came as a result of trying to figure out why boats work, not the other way around. In other words, "form followed function" in boat building for centuries, with designs "field tested" and refined by each new generation of that design. The fact that designers are still often very surprised that a design they thought would be wonderful is a dog, and designs they didn't think much of end up sailing like a witch, is a testament to that. There is still a lot of art to the science of boat design.

[PAR]

This is so very true, frank. Design work was employed by great artists in the past, who I suspect would have been fine art painters if it was not for their upbringing and early experiences, driving them towards yacht design (similar happened to me). I have a large collection of drawings form the "masters" and the detail is usually quite amazing, right down to the grain in the trim pieces, in some cases. It's sad that a lot of these skills are cast aside for a software rendering, sans the wonderful scroll work seen on the bow of an old Chapelle schooner for example.

What Frank really hit on was, the plan fact that the concepts, formulas and understanding we have and incorporated into software are generated from observations and truism, noted long ago buy folks a lot more into it then we. These are the men that swam along side or viewed from afloat near by a new hull form model, being dragged across a pond, by string, just to see if the wake was flatter then the previous version. The skills these men had was well above our modern understanding (a select few noted) and outside the ability of math to describe accurately.

There aren't many truly new ideas in yacht design, generally a revisiting of older ideas, maybe made available because of new materials or processes, or just "to see if it can be made to work". We have the pointy end of the boat in the front, because though many different, not so pointy shapes have been tried, this one seems to dominate in head to head matches. Even the blunt, squared off bow of the lake scow turns into a nicely pointed spear when heeled over on their sailing lines (if you want to go fast take one out for a reach someday, trust me)

Even with the new software available, you'd think anyone could now design a boat and have it come out pretty well. Nope, it requires the user to have more then basic understanding of the concepts and principles, before you can generate a shape that will not go turtle farther from shore than you'd care to swim back to. I learned these skills with a set of fine drawing tools, given to me by my father, made of the best surgical stainless steel and a sweet brass edged slide rule. Those ruling pens and quills were quickly replaced with rapidographs, "T" squares with raised plastic edges and a $200 "TI-99" calculator (which we weren't allowed to use in collage, if you could afford one) The abilities of that calculator can be had on a wrist watch at Wal-Mart for less then 10 bucks now. These were handed over for a mouse and keyboard (my preliminary work is still done by hand then scanned) and with all of this there is still the "good guess" that is performed many times. What appendage works best on this hull form, where should it be located, what shape. There are many formulas that can be used to help with the decision processes, but a good grasp of what works, what didn't and the progressive nature of advancing the design, leaves reasonably one well armed for a good guess. Okay, how many know what a slide rule looks like? How many can use one?

[Stump]

I saw a slide rule once... :roll: They are used by...uhmm...sliding something, right? :wink:

[Steve Day]

There is at least one more guy that remembers what a slide rule is and how to use it.

In my engineering school, they would not let us use calculators and we used slide rules. One of my Profs said that "Why do you need 9 decimal place accuracy in a 3 significant figure world? :wink:

We also had to figure out where the decimal point went rather than just punching numbers into a calculator and reading the answer.

Too bad that slide rules are only found in museums and desk drawers of old guys like us. :roll:

Steve

[Guest]

Sorry, with upmost respect to old folks and their slide rules, some of those old folks and slide rules are superseded by flannel shirts and spotted khakis britches, but seem to ignore that fine tuning of those engineering numbers with other common and historical facts that also makes up museum pieces that works and folks drool over and show their 21st century kids.

[Barry Pyeatt]

AMEN! With great respect for technical tools and the people that use them. I too recall how to use a slide rule. And drafting equipment. I was trained in their use and gave it up to work in a warmer, more dynamic environment.

But sorry to say that in a dynamic environment, such as working with wood in boat building. Fine lines and even 3 place decimal points often have no place except on metal engine tolerances. It takes an appreciation for the character and grain of wood as well as appropriate choices to make up those museum pieces. Along with a love for the "hands on" experience that just doesn't come directly from the drafting board. And it generally stays dynamic as it ages and gets more beautiful.

And please understand, I'm not intendingn to step on anyones toes or question anyones abilities. Just different appreciation levels for traditional building methods and abilities. It will be a sad world indeed when those Old timers that did it the hard way are gone and the gee whiz kids only have the CAD, cold plastic and metal to deal with in a throw away world.

[PAR]

Until very recently I wasn't terribly impressed with the work coming off the screens of the latest designers. Then the "W" class revisited by White and a few others in very near years have begun to show up. With an eye on the artistry of the forms (at least above the waterline) beginning to reappear as options to the cookie cutter offerings available from everyone else. I resent the idea of being one of the old guys, though I did just celebrate the 21st anniversary of my 29th birthday, and am quite rusty, but can use the slide rule. In a lot of calculations, it's faster then the digital version. I have a pony tail (baldness denial) and gray in my beard (which is the only reason I shave) I never wanted to get old, it just kind of snuck up on me. I've repeatedly found the finest designers and engineers are the folks who have hands on experience with the materials the spec out in their design work. This was true in Herreshoff's day and is still accurate today.

[Phil Gowans]

SlideWhat? ... Sliderule, I've heard of that. Oh, yeah I've actually got one of those. No, two of them. I wonder where they are now. Yeah there are a few of us old farts around. Now, if I still had some memory left, all this experience might be worth something.

It's coming to me now, I use to use one of those things to multiply, divide and even more complicated things. Started using the thing over 50 years ago. I remember buying a fancy Versalog rule for college classes (you know with the cool hip case), but I used my little pocket one the most. I go back where we weren't told we couldn't use calculators - there weren't any. Because I was so lazy, I started using a sliderule in Elementry School. My kids can't believe it when I tell them about applied stat classes without anything but a mechanical adding machine. Yeah, those were the days. Sliderules didn't do any good for that kind of calculation. What was really frustrating, I could design a calculator out of nand and nor gates, but didn't have the money to build one.

He He, now this is funny. This spellchecker doesn't recognize the word sliderule.

Sorry about this diatribe, sometimes I'm amazed at how old I really am. Now don't let me start telling you about when we the iceman came 3 times a week to load the icebox.

[Barry Pyeatt]

Phil, you must be old!

It was only my grandparents that didn't have electricity for their icebox. Their icebox was literally a box, dug into the side of their root cellar. I do remember going with my grandfather about 14 miles each way to get ice though in their Model A over logging roads. And no, the roads weren't paved and for most of the way, weren't even gravel or passable in bad weather.

But no, I didn't have to walk miles thru snow drifts to go to school. The school was too far away to walk to. :roll: But the lake sure had good fishing and was a great place to go boating. And the draft horses were fun to ride while dragging the old growth Douglas Fir and Western Red Cedar logs to the lake. When he would get enough logs the mill would send a steam powered boat to tow them down the lake to the mill.

My God, I must be getting old too! :wink:

[hborger]

Barry and Frank

I just back in town and read your posts regarding my mast rake. Hate to bring that subject back from the dynamic slide rule fun. Yes, I own a slide rule (gift from my dad when I went off to engineering school). Wouldn't fit on my belt, so had to upgrade to a calculator to be the model nerd of the 70's. I would like to think we set the trend that led to the mobile phone belt clip.

My mast rake must be off....I'm 5'4 and I have to duck to keep from getting nocked unconcious (although that might improve my personality). I'm off to the lake this weekend for some turnbuckling. thanks.

[Barry Pyeatt]

You might want to check it with an angle keeper and then measure it with a protractor. It is amazing how many notes I'm getting from builders who seem to have a problem and how easy it is to correct for most of them.

In every case so far the boats have handled much better when they get it corrected.

Second biggest difference has been with those that had loose rudder boxes and steering that wobbled. Again the fix was easy, simply placing a tube inside the eyes on the rudder and rudder box to keep things centered and smooth turning.

A couple of builders had major stalling issues due to too much rudder swing combined with too much mast rake. Both were easily corrected in just an afternoon and that took care of things to their satisfaction.

A few have had the angles nearly correct, only off by a couple degrees and they just tightened up on the forestay and it made some positive differences for them. Their concern seemed to be low boom at the helm as well. A couple of them were a result of incorrect measurements on the homemade tarp sails that allowed the foot and clew to set lower than called for.

One recut the foot to the correct measurements and that solved the problem. Lots of head clearance.

Other one just put a 4" block under the tabernacle and lengthened the shrouds and forestay enough to make the difference.

One builder that wrote me has changed to a lapper that he made himself from light weight white poly tarp and David Gray's Polysail directions. He is extremely happy with the difference in handling. He has primarily light wind conditions the majority of the time and the extra sail area forward has helped to balance things out. He said the helm will now stay where he puts it in light air, just requires attention in medium air and only has moderate pressure in meadium-heavy air. He has had other boats and loves this because it is so easy to single hand.

[kydocfrog]

Well, I guess I started something with this thread...

Charlie Girl II is upside down, so I can't go out and fool around with this, but I've got a question about all this I'm reading. Given that the Wkndr mast is set in a pretty deep, rigid sleve and the whole thing has this gate hinge in the rig smak down near the deck, just how much adjustment can you get with wedges or flexing it by cranking down on the forestay. I wouldn't think there is a lot of a) room to wedge one fore and aft or a lot of potential for flex without really stressing that hinge. (I know I'm way ahead of myself here since I don't even have a mast.)

And, speaking of slide rules, as an oldf.rt, I still have one of those in a big blondish leather belt case too. But if you really want think on something that has gone obsolete...consider the drafting studio. As a design student I didn't use the slipstick near as much as all those wonderful compasses and dividers in their fitted cases and parallel rules and drafting machines and leroy letters and tech pens and 8 different shades of grey markers and racks of 6 different grades of pencils and scum bags. Sigh. They don't hardly use those things any more either. Witness some of the drawings that get posted on this site.

Cheers. Going to try to fillet and tape seams this weekend.

DocA

[Barry Pyeatt]

DocA,

Sure, you started a good thread. And it applies to a lot of builders that are wondering "WHY" they have a heavy helm and low boom.

My kids still want to know what the heck the set of drafting pens are for and why I have this huge tilting table still set up in my study. Guess it gets to them even more when I'm using it. Still draft out many projects by hand. Especially modifications and ideas.

I just ask them what they will do when they don't have a CAD system to work with or understand how to use it. I can still work when the power is gone or onsite without it. Still can convey an idea with a good sketch. Don't know many of the whiz kids that can still do that. No offense meant to those that do the work with the systems. Cuz I really appreciate them too. 8)

The wedges will help to keep the mast base stationary in the box and keep things from getting sloppy. No, there isn't much room for adjustment within the box itself. And with the hinge, you really don't have all that much actual rake adjustment on the mast. Yet getting a good balance of tension and adjustment will allow for tuning to some extent on these rigs.

If the mast box is off by several degrees, a wedge can be cut from the back of the mast base corresponding to the amount it is off. The wedge removed can then be attached to the front of the mast base and that will create a bend in the mast and straighten it right up. No issues with strength and the wedges will still lock it in. But now the mast will be at the correct angle and lessen the weather helm.